Module:Citation/CS1: Difference between revisions

    From Nonbinary Wiki
    m>Trappist the monk
    (Fix kerning; tweak doi display;)
    m>Trappist the monk
    (Synch from sandbox;)
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    -- Include translation message hooks, ID and error handling configuration settings.
    -- Include translation message hooks, ID and error handling configuration settings.
    local cfg = mw.loadData( 'Module:Citation/CS1/Configuration' );
    --local cfg = mw.loadData( 'Module:Citation/CS1/Configuration/sandbox' );


    -- Contains a list of all recognized parameters
    -- Contains a list of all recognized parameters
    local whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist' );
    --local whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist/sandbox' );
     
    --local dates = require('Module:Citation/CS1/Date_validation/sandbox').dates -- location of date validation code


    -- Whether variable is set or not
    -- Whether variable is set or not
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    if true ~= Page_in_deprecated_cat then -- if we haven't been here before then set a  
    if true ~= Page_in_deprecated_cat then -- if we haven't been here before then set a  
    Page_in_deprecated_cat=true; -- sticky flag so that if there are more than one deprecated parameter the category is added only once
    Page_in_deprecated_cat=true; -- sticky flag so that if there are more than one deprecated parameter the category is added only once
    table.insert( z.message_tail, { seterror( 'deprecated_params', {error_message}, true ) } ); -- add error message
    -- table.insert( z.message_tail, { seterror( 'deprecated_params', {error_message}, true ) } ); -- add error message
    table.insert( z.message_tail, { seterror( 'deprecated_params', {}, true ) } ); -- add error message
    end
    end
    end
    end
    Line 260: Line 263:
             label=handler.label , prefix="//www.amazon."..domain.."/dp/",id=id,
             label=handler.label , prefix="//www.amazon."..domain.."/dp/",id=id,
             encode=handler.encode, separator = handler.separator})
             encode=handler.encode, separator = handler.separator})
    end
    --[[
    Format LCCN link and do simple error checking.  LCCN is a character string 8-12 characters long. The length of the LCCN dictates the character type of the first 1-3 characters; the
    rightmost eight are always digits. http://info-uri.info/registry/OAIHandler?verb=GetRecord&metadataPrefix=reg&identifier=info:lccn/
    length = 8 then all digits
    length = 9 then lccn[1] is alpha
    length = 10 then lccn[1] and lccn[2] are both alpha or both digits
    length = 11 then lccn[1] is alpha, lccn[2] and lccn[3] are both alpha or both digits
    length = 12 then lccn[1] and lccn[2] are both alpha
    ]]
    function lccn(id)
    local handler = cfg.id_handlers['LCCN'];
    local err_cat =  ''; -- presume that LCCN is valid
    local len = id:len(); -- get the length of the lccn
    if 8 == len then
    if id:match("[^%d]") then -- if LCCN has anything but digits (nil if only digits)
    err_cat = ' ' .. seterror( 'bad_lccn' ); -- set an error message
    end
    elseif 9 == len then -- LCCN should be adddddddd
    if nil == id:match("%a%d%d%d%d%d%d%d%d") then -- does it match our pattern?
    err_cat = ' ' .. seterror( 'bad_lccn' ); -- set an error message
    end
    elseif 10 == len then -- LCCN should be aadddddddd or dddddddddd
    if id:match("[^%d]") then -- if LCCN has anything but digits (nil if only digits) ...
    if nil == id:match("^%a%a%d%d%d%d%d%d%d%d") then -- ... see if it matches our pattern
    err_cat = ' ' .. seterror( 'bad_lccn' ); -- no match, set an error message
    end
    end
    elseif 11 == len then -- LCCN should be aaadddddddd or adddddddddd
    if not (id:match("^%a%a%a%d%d%d%d%d%d%d%d") or id:match("^%a%d%d%d%d%d%d%d%d%d%d")) then -- see if it matches one of our patterns
    err_cat = ' ' .. seterror( 'bad_lccn' ); -- no match, set an error message
    end
    elseif 12 == len then -- LCCN should be aadddddddddd
    if not id:match("^%a%a%d%d%d%d%d%d%d%d%d%d") then -- see if it matches our pattern
    err_cat = ' ' .. seterror( 'bad_lccn' ); -- no match, set an error message
    end
    else
    err_cat = ' ' .. seterror( 'bad_lccn' ); -- wrong length, set an error message
    end
    return externallinkid({link = handler.link, label = handler.label,
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    end


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    --[[
    --[[
    Formats a PMC and checks for embargoed articles. The embargo parameter takes a date for a value. If the embargo date is in the future
    Format a PMC, do simple error checking, and check for embargoed articles.
     
    The embargo parameter takes a date for a value. If the embargo date is in the future
    the PMC identifier will not be linked to the article.  If the embargo specifies a date in the past, or if it is empty or omitted, then
    the PMC identifier will not be linked to the article.  If the embargo specifies a date in the past, or if it is empty or omitted, then
    the PMC identifier is linked to the article through the link at cfg.id_handlers['PMC'].prefix.
    the PMC identifier is linked to the article through the link at cfg.id_handlers['PMC'].prefix.
    PMCs are sequential numbers beginning at 1 and counting up.  This code checks the PMC to see that it contains only digits and is less
    than test_limit; the value in local variable test_limit will need to be updated periodically as more PMCs are issued.
    ]]
    ]]
    function pmc(id, embargo)
    function pmc(id, embargo)
    local test_limit = 5000000; -- update this value as PMCs approach
    local handler = cfg.id_handlers['PMC'];
    local handler = cfg.id_handlers['PMC'];
    local err_cat =  ''; -- presume that PMC is valid
          
          
    local text;
    local text;


    if id:match("[^%d]") then -- if PMC has anything but digits
    err_cat = ' ' .. seterror( 'bad_pmc' ); -- set an error message
    else -- PMC is only digits
    local id_num = tonumber(id); -- convert id to a number for range testing
    if 1 > id_num or test_limit < id_num then -- if PMC is outside test limit boundaries
    err_cat = ' ' .. seterror( 'bad_pmc' ); -- set an error message
    end
    end
    if is_embargoed(embargo) then
    if is_embargoed(embargo) then
    text="[[" .. handler.link .. "|" .. handler.label .. "]]:" .. handler.separator .. id; --still embargoed so no external link
    text="[[" .. handler.link .. "|" .. handler.label .. "]]:" .. handler.separator .. id .. err_cat; --still embargoed so no external link
    else
    else
    text = externallinkid({link = handler.link, label = handler.label, --no embargo date, ok to link to article
    text = externallinkid({link = handler.link, label = handler.label, --no embargo date, ok to link to article
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    end
    return text;
    return text;
    Line 322: Line 388:


    -- Formats a DOI and checks for DOI errors.
    -- Formats a DOI and checks for DOI errors.
    -- DOI names contain two parts: prefix and suffix separated by a forward slash.
    --  Prefix: directory indicator '10.' followed by a registrant code
    --  Suffix: character string of any length chosen by the registrant
    -- This function checks a DOI name for: prefix/suffix.  If the doi name contains spaces or endashes,
    -- or, if it ends with a period or a comma, this function will emit a bad_doi error message.
    -- DOI names are case-insensitive and can incorporate any printable Unicode characters so the test for spaces, endash,
    -- and terminal punctuation may not be technically correct but it appears, that in practice these characters are rarely if ever used in doi names.
    function doi(id, inactive)
    function doi(id, inactive)
         local cat = ""
         local cat = ""
    Line 342: Line 419:
    end
    end


    if nil == id:match("^10%.[^%s–]-[^%.,]$") then -- doi must begin with '10.', must not contain spaces or endashes, and must not end with period or comma
    if nil == id:match("^10%.[^%s–]-/[^%s–]-[^%.,]$") then -- doi must begin with '10.', must contain a fwd slash, must not contain spaces or endashes, and must not end with period or comma
    cat = ' ' .. seterror( 'bad_doi' );
    cat = ' ' .. seterror( 'bad_doi' );
    end
    end
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    end
    end


    if "podcast" == cite_class then -- if this citation is cite podcast
    if "AV media notes" == cite_class or "DVD notes" == cite_class then -- if this citation is cite AV media notes or cite DVD notes
    return "Media notes"; -- display AV media notes / DVD media notes annotation
     
    elseif "podcast" == cite_class then -- if this citation is cite podcast
    return "Podcast"; -- display podcast annotation
    return "Podcast"; -- display podcast annotation


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    end
    end


    -- returns a number according to the month in a date: 1 for January, etcCapitalization and spelling must be correct. If not a valid month, returns 0
    --[[
    function get_month_number (month)
    Determines whether a URL string is valid
    local long_months = {['January']=1, ['February']=2, ['March']=3, ['April']=4, ['May']=5, ['June']=6, ['July']=7, ['August']=8, ['September']=9, ['October']=10, ['November']=11, ['December']=12};
     
    local short_months = {['Jan']=1, ['Feb']=2, ['Mar']=3, ['Apr']=4, ['May']=5, ['Jun']=6, ['Jul']=7, ['Aug']=8, ['Sep']=9, ['Oct']=10, ['Nov']=11, ['Dec']=12};
    At present the only check is whether the string appears to  
    local temp;
    be prefixed with a URI schemeIt is not determined whether
    temp=long_months[month];
    the URI scheme is valid or whether the URL is otherwise well
    if temp then return temp; end -- if month is the long-form name
    formed.
    temp=short_months[month];
    ]]
    if temp then return temp; end -- if month is the short-form name
    function checkurl( url_str )
    return 0; -- misspelled, improper case, or not a month name
        -- Protocol-relative or URL scheme
        return url_str:sub(1,2) == "//" or url_str:match( "^[^/]*:" ) ~= nil;
    end
    end


    -- returns a number according to the sequence of seasons in a year: 1 for Winter, etc.  Capitalization and spelling must be correct. If not a valid season, returns 0
    -- Removes irrelevant text and dashes from ISBN number
    function get_season_number (season)
    -- Similar to that used for Special:BookSources
    local season_list = {['Winter']=1, ['Spring']=2, ['Summer']=3, ['Fall']=4, ['Autumn']=4}
    function cleanisbn( isbn_str )
    local temp;
        return isbn_str:gsub( "[^-0-9X]", "" );
    temp=season_list[season];
    if temp then return temp; end -- if season is a valid name return its number
    return 0; -- misspelled, improper case, or not a season name
    end
    end


    --[[
    -- Extract page numbers from external wikilinks in any of the |page=, |pages=, or |at= parameters for use in COinS.
    Returns true if day is less than or equal to the number of days in month; else returns false.
    function get_coins_pages (pages)
     
    if not is_set (pages) then return pages; end -- if no page numbers then we're done
    Assumes Julian calendar prior to year 1582 and Gregorian calendar thereafter. Accounts for Julian calendar leap years before 1582 and Gregorian leap years after 1582.
    Where the two calendars overlap (1582 to approximately 1923) dates are assumed to be Gregorian.
        while true do
    ]]
    pattern = pages:match("%[([%w/:\.]+%s+)[%w%d].*%]"); -- pattern is the opening bracket, the url and following space(s): "[url "
    function is_valid_date (year, month, day)
    if nil == pattern then break; end -- no more urls
    local days_in_month = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    pages = pages:gsub(pattern, ""); -- remove as many instances of pattern as possible
    local month_length;
    if (2==month) then -- if February
    month_length = 28; -- then 28 days unless
    if 1582 > tonumber(year) then -- Julian calendar
    if 0==(year%4) then
    month_length = 29;
    end
    else -- Gregorian calendar
    if (0==(year%4) and (0~=(year%100) or 0==(year%400))) then -- is a leap year?
    month_length = 29; -- if leap year then 29 days in February
    end
    end
    else
    month_length=days_in_month[month];
    end
    end
     
    pages = pages:gsub("[%[%]]", ""); -- remove the brackets
    if tonumber (day) > month_length then
    pages = pages:gsub("–", "-" ); -- replace endashes with hyphens
    return false;
    pages = pages:gsub("&%w+;", "-" ); -- and replace html entities (&ndash; etc) with hyphens; do we need to replace numerical entities like &#32; and the like?
    end
    return pages;
    return true;
    end
    end


    --[[
    --[[
    Check a pair of months or seasons to see if both are valid members of a month or season pair.
    ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in checkisbn().
     
    If the number is valid the result will be 0. Before calling this function, issbn/issn must be checked for length and stripped of dashes,
    Month pairs are expected to be left to right, earliest to latest in time.  Similarly, seasons are also left to right, earliest to latest in time. There is
    spaces and other non-isxn characters.
    an oddity with seasons.  Winter is assigned a value of 1, spring 2, ..., fall and autumn 4.  Because winter can follow fall/autumn at the end of a calender year, a special test
    is made to see if |date=Fall-Winter yyyy (4-1) is the date.
    ]]
    ]]
     
    function is_valid_isxn (isxn_str, len)
    function is_valid_month_season_range(range_start, range_end)
    local temp = 0;
    local range_start_number = get_month_number (range_start);
    isxn_str = { isxn_str:byte(1, len) }; -- make a table of bytes
    len = len+1; -- adjust to be a loop counter
    if 0 == range_start_number then -- is this a month range?
    for i, v in ipairs( isxn_str ) do -- loop through all of the bytes and calculate the checksum
    local range_start_number = get_season_number (range_start); -- not a month; is it a season? get start season number
    if v == string.byte( "X" ) then -- if checkdigit is X
    local range_end_number = get_season_number (range_end); -- get end season number
    temp = temp + 10*( len - i ); -- it represents 10 decimal
     
    else
    if 0 ~= range_start_number then -- is start of range a season?
    temp = temp + tonumber( string.char(v) )*(len-i);
    if range_start_number < range_end_number then -- range_start is a season
    return true; -- return true when range_end is also a season and follows start season; else false
    end
    if 4 == range_start_number and 1 == range_end_number then -- special case when range is Fall-Winter or Autumn-Winter
    return true;
    end
    end
    end
    return false; -- range_start is not a month or a season; or range_start is a season and range_end is not; or improper season sequence
    end
    end
     
    return temp % 11 == 0; -- returns true if calculation result is zero
    local range_end_number = get_month_number (range_end); -- get end month number
    if range_start_number < range_end_number then -- range_start is a month; does range_start precede range_end?
    return true; -- if yes, return true
    end
    return false; -- range_start month number is greater than or equal to range end number; or range end isn't a month
    end
    end


    --[[
    -- Determines whether an ISBN string is valid
    Check date format to see that it is one of the formats approved by MOS:DATE: MMMM D, YYYY; D MMMM YYYY; MMMM YYYY; YYYY-MM-DD; YYYY.
    function checkisbn( isbn_str )
    Additionally, check the date to see that it is a real date: no 31 in 30-day months; no 29 February when not a leap year. Months, both long-form and three
    if nil ~= isbn_str:match("[^%s-0-9X]") then return false; end -- fail if isbn_str contains anything but digits, hyphens, or the uppercase X
    character abbreviations, and seasons must be spelled correctly.
    isbn_str = isbn_str:gsub( "-", "" ):gsub( " ", "" ); -- remove hyphens and spaces
     
    local len = isbn_str:len();
    If the date fails the fomat tests, this function returns false but does not return values for anchor_year and COinS_date.  When this happens, the date parameter is
       
    used in the COinS metadata and the CITEREF identifier gets its year from the year parameter if present.
    if len ~= 10 and len ~= 13 then
    return false;
    end


    Inputs:
    if len == 10 then
    date_string - date string from date-holding parameters (date, year, accessdate, embargo, archivedate, etc)
    if isbn_str:match( "^%d*X?$" ) == nil then return false; end
    return is_valid_isxn(isbn_str, 10);
    else
    local temp = 0;
    if isbn_str:match( "^97[89]%d*$" ) == nil then return false; end -- isbn13 begins with 978 or 979
    isbn_str = { isbn_str:byte(1, len) };
    for i, v in ipairs( isbn_str ) do
    temp = temp + (3 - 2*(i % 2)) * tonumber( string.char(v) );
    end
    return temp % 10 == 0;
    end
    end


    Returns:
    -- Gets the display text for a wikilink like [[A|B]] or [[B]] gives B
    false if date string is not a real date; else
    function removewikilink( str )
    true, anchor_year, COinS_date
        return (str:gsub( "%[%[([^%[%]]*)%]%]", function(l)
    anchor_year can be used in CITEREF anchors
            return l:gsub( "^[^|]*|(.*)$", "%1" ):gsub("^%s*(.-)%s*$", "%1");
    COinS_date is date_string without anchor_year disambiguator if any
        end));
    ]]
    end
    function check_date (date_string)
    local year;
    local month=0; -- assume that month and day are not used; if either is zero then final year/month/day validation is not necessary
    local day=0;
    local day2=0; -- second day in a day range
    local anchor_year;
    local coins_date;


    if date_string:match("^%d%d%d%d%-%d%d%-%d%d$") then -- Year-initial numerical year month day format
    -- Escape sequences for content that will be used for URL descriptions
    year, month, day=string.match(date_string, "(%d%d%d%d)%-(%d%d)%-(%d%d)");
    function safeforurl( str )
    month=tonumber(month);
        if str:match( "%[%[.-%]%]" ) ~= nil then  
    if 12 < month or 1 > month or 1583 > tonumber(year) then return false; end -- month number not valid or not Gregorian calendar
            table.insert( z.message_tail, { seterror( 'wikilink_in_url', {}, true ) } );
    anchor_year = year;
        end
     
       
    elseif date_string:match("^%a+ +[1-9]%d?, +[1-9]%d%d%d%a?$") then -- month-initial: month day, year
        return str:gsub( '[%[%]\n]', {   
    month, day, anchor_year, year=string.match(date_string, "(%a+)%s*(%d%d?),%s*((%d%d%d%d)%a?)");
            ['['] = '&#91;',
    month = get_month_number (month);
            [']'] = '&#93;',
    if 0 == month then return false; end -- return false if month text isn't one of the twelve months
            ['\n'] = ' ' } );
    end
    elseif date_string:match("^%a+ +[1-9]%d?–[1-9]%d?, +[1-9]%d%d%d%a?$") then -- month-initial day range: month day–day, year; days are separated by endash
    month, day, day2, anchor_year, year=string.match(date_string, "(%a+) +(%d%d?)–(%d%d?), +((%d%d%d%d)%a?)");
    if tonumber(day) >= tonumber(day2) then return false; end -- date range order is left to right: earlier to later; dates may not be the same;
    month = get_month_number (month);
    if 0 == month then return false; end -- return false if month text isn't one of the twelve months


    elseif date_string:match("^[1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then -- day-initial: day month year
    -- Converts a hyphen to a dash
    day, month, anchor_year, year=string.match(date_string, "(%d%d*)%s*(%a+)%s*((%d%d%d%d)%a?)");
    function hyphentodash( str )
    month = get_month_number (month);
        if not is_set(str) or str:match( "[%[%]{}<>]" ) ~= nil then
    if 0 == month then return false; end -- return false if month text isn't one of the twelve months
            return str;
        end   
        return str:gsub( '-', '–' );
    end


    elseif date_string:match("^[1-9]%d?–[1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then -- day-range-initial: day–day month year; days are separated by endash
    -- Protects a string that will be wrapped in wiki italic markup '' ... ''
    day, day2, month, anchor_year, year=string.match(date_string, "(%d%d?)–(%d%d?) +(%a+) +((%d%d%d%d)%a?)");
    function safeforitalics( str )
    if tonumber(day) >= tonumber(day2) then return false; end -- date range order is left to right: earlier to later; dates may not be the same;
        --[[ Note: We can not use <i> for italics, as the expected behavior for
    month = get_month_number (month);
        italics specified by ''...'' in the title is that they will be inverted
    if 0 == month then return false; end -- return false if month text isn't one of the twelve months
        (i.e. unitalicized) in the resulting references.  In addition, <i> and ''
     
        tend to interact poorly under Mediawiki's HTML tidy. ]]
    elseif mw.ustring.match (date_string, "^%a+–%a+ +[1-9]%d%d%d%a?$") then -- month/season range year; months separated by endash
       
    local month2
        if not is_set(str) then
    month, month2, anchor_year, year=mw.ustring.match (date_string, "(%a+)[%-/–](%a+)%s*((%d%d%d%d)%a?)");
            return str;
    if false == is_valid_month_season_range(month, month2) then
        else
    return false;
            if str:sub(1,1) == "'" then str = "<span />" .. str; end
    end
            if str:sub(-1,-1) == "'" then str = str .. "<span />"; end
           
    elseif date_string:match("^%a+ +%d%d%d%d%a?$") then -- month/season year
            -- Remove newlines as they break italics.
    month, anchor_year, year=string.match(date_string, "(%a+)%s*((%d%d%d%d)%a?)");
            return str:gsub( '\n', ' ' );
    if 0 == get_month_number (month) then -- if month text isn't one of the twelve months, might be a season
        end
    if 0 == get_season_number (month) then -- not a month, is it a season?
    end
    return false; -- return false not a month or one of the five seasons
    end
    end
     
    elseif date_string:match("^[1-9]%d%d%d?%a?$") then -- year; here accept either YYY or YYYY
    anchor_year, year=string.match(date_string, "((%d%d%d%d?)%a?)");
     
    else
    return false; -- date format not one of the MOS:DATE approved formats
    end
     
    if 0~=month and 0~=day then -- check year month day dates for validity
    if 0~=day2 then -- If there is a second day (d–d Mmm YYYY or Mmm d–d, YYYY) test the second date
    if false==is_valid_date(year,month,day2) then
    return false; -- second date in date range string is not a real date return false; unset anchor_year and coins_date
    end -- if second date range string is valid, fall through to test the first date range
    end
    if false==is_valid_date(year,month,day) then
    return false; -- date string is not a real date return false; unset anchor_year and coins_date
    end
    end
     
    coins_date= mw.ustring.gsub( date_string, "–", "-" ); -- if here, then date_string is valid; set coins_date and replace any ndash with a hyphen
    return true, anchor_year, coins_date; -- format is good and date string represents a real date
    end


    --[[
    --[[
    Cycle the date-holding parameters in passed table date_parameters_list through check_date() to check compliance with MOS:DATE. For all valid dates, check_date() returns
    Joins a sequence of strings together while checking for duplicate separation
    true and values for anchor_year (used in CITEREF identifiers) and COinS_date (used in the COinS metadata).  The |date= parameter test is unique.  This function only
    characters.
    accepts anchor_year and COinS_date results from the |date= parameter test and |date= is the only date-holding parameter that is allowed to contain the no-date keywords
    "n.d." or "nd" (without quotes).
     
    Unlike most error messages created in this module, only one error message is created by this function. Because all of the date holding parameters are processed serially,
    a single error message is created as the dates are tested.
    ]]
    ]]
    function safejoin( tbl, duplicate_char )
        --[[
        Note: we use string functions here, rather than ustring functions.
       
        This has considerably faster performance and should work correctly as
        long as the duplicate_char is strict ASCII.  The strings
        in tbl may be ASCII or UTF8.
        ]]
       
        local str = '';
        local comp = '';
        local end_chr = '';
        local trim;
        for _, value in ipairs( tbl ) do
            if value == nil then value = ''; end
           
            if str == '' then
                str = value;
            elseif value ~= '' then
                if value:sub(1,1) == '<' then
                    -- Special case of values enclosed in spans and other markup.
                    comp = value:gsub( "%b<>", "" );
                else
                    comp = value;
                end
               
                if comp:sub(1,1) == duplicate_char then
                    trim = false;
                    end_chr = str:sub(-1,-1);
                    -- str = str .. "<HERE(enchr=" .. end_chr.. ")"
                    if end_chr == duplicate_char then
                        str = str:sub(1,-2);
                    elseif end_chr == "'" then
                        if str:sub(-3,-1) == duplicate_char .. "''" then
                            str = str:sub(1, -4) .. "''";
                        elseif str:sub(-5,-1) == duplicate_char .. "]]''" then
                            trim = true;
                        elseif str:sub(-4,-1) == duplicate_char .. "]''" then
                            trim = true;
                        end
                    elseif end_chr == "]" then
                        if str:sub(-3,-1) == duplicate_char .. "]]" then
                            trim = true;
                        elseif str:sub(-2,-1) == duplicate_char .. "]" then
                            trim = true;
                        end
                    elseif end_chr == " " then
                        if str:sub(-2,-1) == duplicate_char .. " " then
                            str = str:sub(1,-3);
                        end
                    end


    function dates(date_parameters_list)
                    if trim then
    local anchor_year; -- will return as nil if the date being tested is not |date=
                        if value ~= comp then
    local COinS_date; -- will return as nil if the date being tested is not |date=
                            local dup2 = duplicate_char;
    local error_message ="";
                            if dup2:match( "%A" ) then dup2 = "%" .. dup2; end
    local good_date=false;
                           
                            value = value:gsub( "(%b<>)" .. dup2, "%1", 1 )
    for k, v in pairs(date_parameters_list) do -- for each date-holding parameter in the list
                        else
    if is_set(v) then -- if the parameter has a value
                            value = value:sub( 2, -1 );
    if v:match("^c%. [1-9]%d%d%d?%a?$") then -- special case for c. year or with or without CITEREF disambiguator - only |date= and |year=
                        end
    if 'date'==k then
                    end
    good_date, anchor_year, COinS_date = true, v:match("((c%. [1-9]d%d%d?)%a?)"); -- anchor year and COinS_date only from |date= parameter
                end
    elseif 'year'==k then
                str = str .. value;
    good_date =  true;
            end
    end
         end
    elseif 'year'==k then -- if the parameter is |year= (but not c. year)
         return str;
    if v:match("^[1-9]%d%d%d?%a?$") then -- year with or without CITEREF disambiguator
    end
    good_date =  true;
    end
    elseif 'date'==k then -- if the parameter is |date=
    if v:match("n%.d%.%a?") then -- if |date=n.d. with or without a CITEREF disambiguator
    good_date, anchor_year, COinS_date = true, v:match("((n%.d%.)%a?)"); --"n.d."; no error when date parameter is set to no date
    elseif v:match("nd%a?$") then -- if |date=nd with or without a CITEREF disambiguator
    good_date, anchor_year, COinS_date = true, v:match("((nd)%a?)"); --"nd"; no error when date parameter is set to no date
    else
    good_date, anchor_year, COinS_date = check_date (v); -- go test the date
    end
    else -- any other date-holding parameter
    good_date = check_date (v); -- go test the date
    end
    if false==good_date then -- assemble one error message so we don't add the tracking category multiple times
    if is_set(error_message) then -- once we've added the first portion of the error message ...
    error_message=error_message .. ", "; -- ... add a comma space separator
    end
    error_message=error_message .. "&#124;" .. k .. "="; -- add the failed parameter
    end
    end
    end
    if is_set(error_message) then
    table.insert( z.message_tail, { seterror( 'bad_date', {error_message}, true ) } ); -- add this error message
    end
     
    return anchor_year, COinS_date; -- and done
    end
     
    --[[
    Determines whether a URL string is valid
     
    At present the only check is whether the string appears to
    be prefixed with a URI scheme.  It is not determined whether
    the URI scheme is valid or whether the URL is otherwise well
    formed.
    ]]
    function checkurl( url_str )
        -- Protocol-relative or URL scheme
         return url_str:sub(1,2) == "//" or url_str:match( "^[^/]*:" ) ~= nil;
    end
     
    -- Removes irrelevant text and dashes from ISBN number
    -- Similar to that used for Special:BookSources
    function cleanisbn( isbn_str )
         return isbn_str:gsub( "[^-0-9X]", "" );
    end
     
    --[[
    ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in checkisbn().
    If the number is valid the result will be 0. Before calling this function, issbn/issn must be checked for length and stripped of dashes,
    spaces and other non-isxn characters.
    ]]
    function is_valid_isxn (isxn_str, len)
    local temp = 0;
    isxn_str = { isxn_str:byte(1, len) }; -- make a table of bytes
    len = len+1; -- adjust to be a loop counter
    for i, v in ipairs( isxn_str ) do -- loop through all of the bytes and calculate the checksum
    if v == string.byte( "X" ) then -- if checkdigit is X
    temp = temp + 10*( len - i ); -- it represents 10 decimal
    else
    temp = temp + tonumber( string.char(v) )*(len-i);
    end
    end
    return temp % 11 == 0; -- returns true if calculation result is zero
    end


    -- Determines whether an ISBN string is valid
    -- Attempts to convert names to initials.
    function checkisbn( isbn_str )
    function reducetoinitials(first)
    if nil ~= isbn_str:match("[^%s-0-9X]") then return false; end -- fail if isbn_str contains anything but digits, hyphens, or the uppercase X
        local initials = {}
    isbn_str = isbn_str:gsub( "-", "" ):gsub( " ", "" ); -- remove hyphens and spaces
        for word in string.gmatch(first, "%S+") do
    local len = isbn_str:len();
            table.insert(initials, string.sub(word,1,1)) -- Vancouver format does not include full stops.
        end
    if len ~= 10 and len ~= 13 then
        return table.concat(initials) -- Vancouver format does not include spaces.
    return false;
    end
     
    if len == 10 then
    if isbn_str:match( "^%d*X?$" ) == nil then return false; end
    return is_valid_isxn(isbn_str, 10);
    else
    local temp = 0;
    if isbn_str:match( "^97[89]%d*$" ) == nil then return false; end -- isbn13 begins with 978 or 979
    isbn_str = { isbn_str:byte(1, len) };
    for i, v in ipairs( isbn_str ) do
    temp = temp + (3 - 2*(i % 2)) * tonumber( string.char(v) );
    end
    return temp % 10 == 0;
    end
    end
    end


    -- Gets the display text for a wikilink like [[A|B]] or [[B]] gives B
    -- Formats a list of people (e.g. authors / editors)
    function removewikilink( str )
    function listpeople(control, people)
         return (str:gsub( "%[%[([^%[%]]*)%]%]", function(l)
         local sep = control.sep;
            return l:gsub( "^[^|]*|(.*)$", "%1" ):gsub("^%s*(.-)%s*$", "%1");
        local namesep = control.namesep
         end));
        local format = control.format
    end
        local maximum = control.maximum
     
         local lastauthoramp = control.lastauthoramp;
    -- Escape sequences for content that will be used for URL descriptions
        local text = {}
    function safeforurl( str )
        local etal = false;
         if str:match( "%[%[.-%]%]" ) ~= nil then  
       
            table.insert( z.message_tail, { seterror( 'wikilink_in_url', {}, true ) } );
         if sep:sub(-1,-1) ~= " " then sep = sep .. " " end
        end
        if maximum ~= nil and maximum < 1 then return "", 0; end
          
          
         return str:gsub( '[%[%]\n]', {   
         for i,person in ipairs(people) do
            ['['] = '&#91;',
            if is_set(person.last) then
            [']'] = '&#93;',
                local mask = person.mask
            ['\n'] = ' ' } );
                local one
    end
                local sep_one = sep;
                if maximum ~= nil and i > maximum then
                    etal = true;
                    break;
                elseif (mask ~= nil) then
                    local n = tonumber(mask)
                    if (n ~= nil) then
                        one = string.rep("&mdash;",n)
                    else
                        one = mask;
                        sep_one = " ";
                    end
                else
                    one = person.last
                    local first = person.first
                    if is_set(first) then
                        if ( "vanc" == format ) then first = reducetoinitials(first) end
                        one = one .. namesep .. first
                    end
                    if is_set(person.link) then one = "[[" .. person.link .. "|" .. one .. "]]" end
                    if is_set(person.link) and nil ~= person.link:find("//") then one = one .. " " .. seterror( 'bad_authorlink' ) end -- check for url in author link;
                end
                table.insert( text, one )
                table.insert( text, sep_one )
            end
        end


    -- Converts a hyphen to a dash
        local count = #text / 2;
    function hyphentodash( str )
        if count > 0 then
        if not is_set(str) or str:match( "[%[%]{}<>]" ) ~= nil then
            if count > 1 and is_set(lastauthoramp) and not etal then
             return str;
                text[#text-2] = " & ";
         end  
            end
         return str:gsub( '-', '' );
            text[#text] = nil;
        end
       
        local result = table.concat(text) -- construct list
        if etal then  
             local etal_text = cfg.messages['et al'];
            result = result .. " " .. etal_text;
         end
          
        -- if necessary wrap result in <span> tag to format in Small Caps
        if ( "scap" == format ) then result =
            '<span class="smallcaps" style="font-variant:small-caps">' .. result .. '</span>';
        end
        return result, count
    end
    end


    -- Protects a string that will be wrapped in wiki italic markup '' ... ''
    -- Generates a CITEREF anchor ID.
    function safeforitalics( str )
    function anchorid( options )
         --[[ Note: We can not use <i> for italics, as the expected behavior for
         return "CITEREF" .. table.concat( options );
        italics specified by ''...'' in the title is that they will be inverted
    end
        (i.e. unitalicized) in the resulting references.  In addition, <i> and ''
        tend to interact poorly under Mediawiki's HTML tidy. ]]
       
        if not is_set(str) then
            return str;
        else
            if str:sub(1,1) == "'" then str = "<span />" .. str; end
            if str:sub(-1,-1) == "'" then str = str .. "<span />"; end
           
            -- Remove newlines as they break italics.
            return str:gsub( '\n', ' ' );
        end
    end


    --[[
    -- Gets name list from the input arguments
    Joins a sequence of strings together while checking for duplicate separation
    function extractnames(args, list_name)
    characters.
         local names = {};
    ]]
        local i = 1;
    function safejoin( tbl, duplicate_char )
         local last;
         --[[
         Note: we use string functions here, rather than ustring functions.
          
          
         This has considerably faster performance and should work correctly as
         while true do
        long as the duplicate_char is strict ASCII. The strings
            last = selectone( args, cfg.aliases[list_name .. '-Last'], 'redundant_parameters', i );
        in tbl may be ASCII or UTF8.
            if not is_set(last) then
        ]]
                -- just in case someone passed in an empty parameter
       
                break;
        local str = '';
            end
        local comp = '';
            names[i] = {
        local end_chr = '';
                last = last,
         local trim;
                first = selectone( args, cfg.aliases[list_name .. '-First'], 'redundant_parameters', i ),
         for _, value in ipairs( tbl ) do
                link = selectone( args, cfg.aliases[list_name .. '-Link'], 'redundant_parameters', i ),
             if value == nil then value = ''; end
                mask = selectone( args, cfg.aliases[list_name .. '-Mask'], 'redundant_parameters', i )
           
            };
             if str == '' then
            i = i + 1;
                str = value;
        end
            elseif value ~= '' then
        return names;
                if value:sub(1,1) == '<' then
    end
                    -- Special case of values enclosed in spans and other markup.
     
                    comp = value:gsub( "%b<>", "" );
    -- Populates ID table from arguments using configuration settings
                else
    function extractids( args )
                    comp = value;
         local id_list = {};
                end
         for k, v in pairs( cfg.id_handlers ) do  
               
             v = selectone( args, v.parameters, 'redundant_parameters' );
                if comp:sub(1,1) == duplicate_char then
             if is_set(v) then id_list[k] = v; end
                    trim = false;
        end
                    end_chr = str:sub(-1,-1);
        return id_list;
                    -- str = str .. "<HERE(enchr=" .. end_chr.. ")"
    end
                    if end_chr == duplicate_char then
     
                        str = str:sub(1,-2);
    -- Takes a table of IDs and turns it into a table of formatted ID outputs.
                    elseif end_chr == "'" then
    function buildidlist( id_list, options )
                        if str:sub(-3,-1) == duplicate_char .. "''" then
        local new_list, handler = {};
                            str = str:sub(1, -4) .. "''";
       
                        elseif str:sub(-5,-1) == duplicate_char .. "]]''" then
        function fallback(k) return { __index = function(t,i) return cfg.id_handlers[k][i] end } end;
                            trim = true;
       
                        elseif str:sub(-4,-1) == duplicate_char .. "]''" then
        for k, v in pairs( id_list ) do
                            trim = true;
            -- fallback to read-only cfg
                        end
            handler = setmetatable( { ['id'] = v }, fallback(k) );
                    elseif end_chr == "]" then
           
                        if str:sub(-3,-1) == duplicate_char .. "]]" then
            if handler.mode == 'external' then
                            trim = true;
                table.insert( new_list, {handler.label, externallinkid( handler ) } );
                        elseif str:sub(-2,-1) == duplicate_char .. "]" then
            elseif handler.mode == 'internal' then
                            trim = true;
                table.insert( new_list, {handler.label, internallinkid( handler ) } );
                        end
            elseif handler.mode ~= 'manual' then
                    elseif end_chr == " " then
                error( cfg.messages['unknown_ID_mode'] );
                        if str:sub(-2,-1) == duplicate_char .. " " then
            elseif k == 'DOI' then
                            str = str:sub(1,-3);
                table.insert( new_list, {handler.label, doi( v, options.DoiBroken ) } );
                        end
            elseif k == 'ASIN' then
                    end
                table.insert( new_list, {handler.label, amazon( v, options.ASINTLD ) } );  
     
            elseif k == 'LCCN' then
                    if trim then
                table.insert( new_list, {handler.label, lccn( v ) } );
                        if value ~= comp then  
            elseif k == 'OL' then
                            local dup2 = duplicate_char;
                table.insert( new_list, {handler.label, openlibrary( v ) } );
                            if dup2:match( "%A" ) then dup2 = "%" .. dup2; end
            elseif k == 'PMC' then
                           
                table.insert( new_list, {handler.label, pmc( v, options.Embargo ) } );
                            value = value:gsub( "(%b<>)" .. dup2, "%1", 1 )
            elseif k == 'PMID' then
                        else
                table.insert( new_list, {handler.label, pmid( v ) } );
                            value = value:sub( 2, -1 );
            elseif k == 'ISSN' then
                        end
            table.insert( new_list, {handler.label, issn( v ) } );
                    end
            elseif k == 'ISBN' then
                local ISBN = internallinkid( handler );
                if not checkisbn( v ) and not is_set(options.IgnoreISBN) then
                    ISBN = ISBN .. seterror( 'bad_isbn', {}, false, " ", "" );
                 end
                 end
                 str = str .. value;
                 table.insert( new_list, {handler.label, ISBN } );               
            else
                error( cfg.messages['unknown_manual_ID'] );
             end
             end
         end
         end
         return str;
          
    end
        function comp( a, b ) -- used in following table.sort()
     
            return a[1] < b[1];
    -- Attempts to convert names to initials.
        end
    function reducetoinitials(first)
       
        local initials = {}
        table.sort( new_list, comp );
         for word in string.gmatch(first, "%S+") do
         for k, v in ipairs( new_list ) do
             table.insert(initials, string.sub(word,1,1)) -- Vancouver format does not include full stops.
             new_list[k] = v[2];
         end
         end
         return table.concat(initials) -- Vancouver format does not include spaces.
       
         return new_list;
    end
    end
     
     
    -- Formats a list of people (e.g. authors / editors)
    -- Chooses one matching parameter from a list of parameters to consider
    function listpeople(control, people)
    -- Generates an error if more than one match is present.
         local sep = control.sep;
    function selectone( args, possible, error_condition, index )
         local namesep = control.namesep
         local value = nil;
        local format = control.format
         local selected = '';
        local maximum = control.maximum
         local error_list = {};
        local lastauthoramp = control.lastauthoramp;
         local text = {}
        local etal = false;
          
          
         if sep:sub(-1,-1) ~= " " then sep = sep .. " " end
         if index ~= nil then index = tostring(index); end
        if maximum ~= nil and maximum < 1 then return "", 0; end
          
          
         for i,person in ipairs(people) do
         -- Handle special case of "#" replaced by empty string
            if is_set(person.last) then
        if index == '1' then
                local mask = person.mask
            for _, v in ipairs( possible ) do
                local one
                v = v:gsub( "#", "" );
                local sep_one = sep;
                 if is_set(args[v]) then
                 if maximum ~= nil and i > maximum then
                     if value ~= nil and selected ~= v then
                    etal = true;
                         table.insert( error_list, v );
                    break;
                     else
                elseif (mask ~= nil) then
                         value = args[v];
                    local n = tonumber(mask)
                         selected = v;
                     if (n ~= nil) then
                         one = string.rep("&mdash;",n)
                     else
                         one = mask;
                         sep_one = " ";
                     end
                     end
                else
                    one = person.last
                    local first = person.first
                    if is_set(first) then
                        if ( "vanc" == format ) then first = reducetoinitials(first) end
                        one = one .. namesep .. first
                    end
                    if is_set(person.link) then one = "[[" .. person.link .. "|" .. one .. "]]" end
                 end
                 end
                table.insert( text, one )
             end      
                table.insert( text, sep_one )
             end
        end
     
        local count = #text / 2;
        if count > 0 then
            if count > 1 and is_set(lastauthoramp) and not etal then
                text[#text-2] = " & ";
            end
            text[#text] = nil;
         end
         end
          
          
         local result = table.concat(text) -- construct list
         for _, v in ipairs( possible ) do
        if etal then  
            if index ~= nil then
            local etal_text = cfg.messages['et al'];
                v = v:gsub( "#", index );
            result = result .. " " .. etal_text;
            end
            if is_set(args[v]) then
                if value ~= nil and selected ~= v then
                    table.insert( error_list, v );
                else
                    value = args[v];
                    selected = v;
                end
            end
         end
         end
          
          
         -- if necessary wrap result in <span> tag to format in Small Caps
         if #error_list > 0 then
        if ( "scap" == format ) then result =
            local error_str = "";
            '<span class="smallcaps" style="font-variant:small-caps">' .. result .. '</span>';
            for _, k in ipairs( error_list ) do
        end  
                if error_str ~= "" then error_str = error_str .. cfg.messages['parameter-separator'] end
        return result, count
                error_str = error_str .. wrap( 'parameter', k );
    end
            end
     
            if #error_list > 1 then
    -- Generates a CITEREF anchor ID.
                error_str = error_str .. cfg.messages['parameter-final-separator'];
    function anchorid( options )
            else
        return "CITEREF" .. table.concat( options );
                error_str = error_str .. cfg.messages['parameter-pair-separator'];
            end
            error_str = error_str .. wrap( 'parameter', selected );
            table.insert( z.message_tail, { seterror( error_condition, {error_str}, true ) } );
        end
       
        return value, selected;
    end
    end


    -- Gets name list from the input arguments
    -- COinS metadata (see <http://ocoins.info/>) allows automated tools to parse
    function extractnames(args, list_name)
    -- the citation information.
         local names = {};
    function COinS(data)
         local i = 1;
         if 'table' ~= type(data) or nil == next(data) then
         local last;
            return '';
         end
       
         local ctx_ver = "Z39.88-2004";
          
          
         while true do
         -- treat table strictly as an array with only set values.
             last = selectone( args, cfg.aliases[list_name .. '-Last'], 'redundant_parameters', i );
        local OCinSoutput = setmetatable( {}, {
            if not is_set(last) then
             __newindex = function(self, key, value)
                -- just in case someone passed in an empty parameter
                if is_set(value) then
                 break;
                    rawset( self, #self+1, table.concat{ key, '=', mw.uri.encode( removewikilink( value ) ) } );
                 end
             end
             end
             names[i] = {
        });
                last = last,
       
                first = selectone( args, cfg.aliases[list_name .. '-First'], 'redundant_parameters', i ),
        if is_set(data.Chapter) then
                link = selectone( args, cfg.aliases[list_name .. '-Link'], 'redundant_parameters', i ),
            OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
                mask = selectone( args, cfg.aliases[list_name .. '-Mask'], 'redundant_parameters', i )
             OCinSoutput["rft.genre"] = "bookitem";
             };
            OCinSoutput["rft.btitle"] = data.Chapter;
             i = i + 1;
            OCinSoutput["rft.atitle"] = data.Title;
        end
        elseif is_set(data.Periodical) then
        return names;
             OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:journal";
    end
             OCinSoutput["rft.genre"] = "article";
     
            OCinSoutput["rft.jtitle"] = data.Periodical;
    -- Populates ID table from arguments using configuration settings
            OCinSoutput["rft.atitle"] = data.Title;
    function extractids( args )
         else
        local id_list = {};
            OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
         for k, v in pairs( cfg.id_handlers ) do   
             OCinSoutput["rft.genre"] = "book"
             v = selectone( args, v.parameters, 'redundant_parameters' );
             OCinSoutput["rft.btitle"] = data.Title;
             if is_set(v) then id_list[k] = v; end
         end
         end
        return id_list;
    end
    -- Takes a table of IDs and turns it into a table of formatted ID outputs.
    function buildidlist( id_list, options )
        local new_list, handler = {};
          
          
         function fallback(k) return { __index = function(t,i) return cfg.id_handlers[k][i] end } end;
         OCinSoutput["rft.place"] = data.PublicationPlace;
        OCinSoutput["rft.date"] = data.Date;
        OCinSoutput["rft.series"] = data.Series;
        OCinSoutput["rft.volume"] = data.Volume;
        OCinSoutput["rft.issue"] = data.Issue;
        OCinSoutput["rft.pages"] = data.Pages;
        OCinSoutput["rft.edition"] = data.Edition;
        OCinSoutput["rft.pub"] = data.PublisherName;
          
          
         for k, v in pairs( id_list ) do
         for k, v in pairs( data.ID_list ) do
             -- fallback to read-only cfg
             local id, value = cfg.id_handlers[k].COinS;
             handler = setmetatable( { ['id'] = v }, fallback(k) );
             if k == 'ISBN' then value = cleanisbn( v ); else value = v; end
           
             if string.sub( id or "", 1, 4 ) == 'info' then
             if handler.mode == 'external' then
                 OCinSoutput["rft_id"] = table.concat{ id, "/", v };
                table.insert( new_list, {handler.label, externallinkid( handler ) } );
             else
            elseif handler.mode == 'internal' then
                 OCinSoutput[ id ] = value;
                 table.insert( new_list, {handler.label, internallinkid( handler ) } );
             end
             elseif handler.mode ~= 'manual' then
        end
                 error( cfg.messages['unknown_ID_mode'] );
       
             elseif k == 'DOI' then
        local last, first;
                table.insert( new_list, {handler.label, doi( v, options.DoiBroken ) } );
        for k, v in ipairs( data.Authors ) do
            elseif k == 'ASIN' then
             last, first = v.last, v.first;
                table.insert( new_list, {handler.label, amazon( v, options.ASINTLD ) } );
             if k == 1 then
             elseif k == 'OL' then
                 if is_set(last) then
                table.insert( new_list, {handler.label, openlibrary( v ) } );
                    OCinSoutput["rft.aulast"] = last;
            elseif k == 'PMC' then
                 end
                table.insert( new_list, {handler.label, pmc( v, options.Embargo ) } );
                 if is_set(first) then  
             elseif k == 'PMID' then
                     OCinSoutput["rft.aufirst"] = first;
                 table.insert( new_list, {handler.label, pmid( v ) } );
            elseif k == 'ISSN' then
            table.insert( new_list, {handler.label, issn( v ) } );
            elseif k == 'ISBN' then
                 local ISBN = internallinkid( handler );
                 if not checkisbn( v ) and not is_set(options.IgnoreISBN) then
                     ISBN = ISBN .. seterror( 'bad_isbn', {}, false, " ", "" );
                 end
                 end
                 table.insert( new_list, {handler.label, ISBN } );              
            end
             else
            if is_set(last) and is_set(first) then
                 error( cfg.messages['unknown_manual_ID'] );
                 OCinSoutput["rft.au"] = table.concat{ last, ", ", first };
             elseif is_set(last) then
                 OCinSoutput["rft.au"] = last;
             end
             end
         end
         end
          
          
         function comp( a, b ) -- used in following table.sort()
         OCinSoutput.rft_id = data.URL;
            return a[1] < b[1];
        OCinSoutput.rfr_id = table.concat{ "info:sid/", mw.site.server:match( "[^/]*$" ), ":", data.RawPage };
         end
         OCinSoutput = setmetatable( OCinSoutput, nil );
          
          
         table.sort( new_list, comp );
        -- sort with version string always first, and combine.
         for k, v in ipairs( new_list ) do
         table.sort( OCinSoutput );
            new_list[k] = v[2];
         table.insert( OCinSoutput, 1, "ctx_ver=" .. ctx_ver ); -- such as "Z39.88-2004"
        end
         return table.concat(OCinSoutput, "&");
       
         return new_list;
    end
    end
     
     
    -- Chooses one matching parameter from a list of parameters to consider
    --[[
    -- Generates an error if more than one match is present.
    This is the main function doing the majority of the citation
    function selectone( args, possible, error_condition, index )
    formatting.
         local value = nil;
    ]]
         local selected = '';
    function citation0( config, args)
         local error_list = {};
        --[[
       
        Load Input Parameters
         if index ~= nil then index = tostring(index); end
        The argment_wrapper facillitates the mapping of multiple
        aliases to single internal variable.
        ]]
         local A = argument_wrapper( args );
     
         local i
        local PPrefix = A['PPrefix']
         local PPPrefix = A['PPPrefix']
         if is_set( A['NoPP'] ) then PPPrefix = "" PPrefix = "" end
          
          
         -- Handle special case of "#" replaced by empty string
         -- Pick out the relevant fields from the arguments.  Different citation templates
         if index == '1' then
        -- define different field names for the same underlying things.   
            for _, v in ipairs( possible ) do
         local Authors = A['Authors'];
                v = v:gsub( "#", "" );
        local a = extractnames( args, 'AuthorList' );
                if is_set(args[v]) then
     
                    if value ~= nil and selected ~= v then
        local Coauthors = A['Coauthors'];
                        table.insert( error_list, v );
        local Others = A['Others'];
                    else
        local Editors = A['Editors'];
                        value = args[v];
        local e = extractnames( args, 'EditorList' );
                        selected = v;
     
                    end
        local Year = A['Year'];
                end
        local PublicationDate = A['PublicationDate'];
            end       
        local OrigYear = A['OrigYear'];
         end
        local Date = A['Date'];
          
        local LayDate = A['LayDate'];
         for _, v in ipairs( possible ) do
        ------------------------------------------------- Get title data
            if index ~= nil then
        local Title = A['Title'];
                v = v:gsub( "#", index );
        local BookTitle = A['BookTitle'];
            end
        local Conference = A['Conference'];
            if is_set(args[v]) then
        local TransTitle = A['TransTitle'];
                if value ~= nil and selected ~= v then
        local TitleNote = A['TitleNote'];
                    table.insert( error_list, v );
        local TitleLink = A['TitleLink'];
                else
        local Chapter = A['Chapter'];
                    value = args[v];
        local ChapterLink = A['ChapterLink'];
                    selected = v;
        local TransChapter = A['TransChapter'];
                end
        local TitleType = A['TitleType'];
            end
        local Degree = A['Degree'];
         end
        local Docket = A['Docket'];
         local ArchiveURL = A['ArchiveURL'];
         local URL = A['URL']
         local URLorigin = A:ORIGIN('URL');
        local ChapterURL = A['ChapterURL'];
        local ChapterURLorigin = A:ORIGIN('ChapterURL');
        local ConferenceURL = A['ConferenceURL'];
        local ConferenceURLorigin = A:ORIGIN('ConferenceURL');
        local Periodical = A['Periodical'];
     
    local Series = A['Series'];
        local Volume = A['Volume'];
        local Issue = A['Issue'];
        local Position = '';
        local Page = A['Page'];
        local Pages = hyphentodash( A['Pages'] );
        local At = A['At'];
     
        local Edition = A['Edition'];
        local PublicationPlace = A['PublicationPlace']
         local Place = A['Place'];
          
          
         if #error_list > 0 then
         local PublisherName = A['PublisherName'];
            local error_str = "";
        local RegistrationRequired = A['RegistrationRequired'];
            for _, k in ipairs( error_list ) do
        local SubscriptionRequired = A['SubscriptionRequired'];
                if error_str ~= "" then error_str = error_str .. cfg.messages['parameter-separator'] end
        local Via = A['Via'];
                error_str = error_str .. wrap( 'parameter', k );
        local AccessDate = A['AccessDate'];
            end
        local ArchiveDate = A['ArchiveDate'];
            if #error_list > 1 then
        local Agency = A['Agency'];
                error_str = error_str .. cfg.messages['parameter-final-separator'];
        local DeadURL = A['DeadURL']
            else
        local Language = A['Language'];
                error_str = error_str .. cfg.messages['parameter-pair-separator'];
        local Format = A['Format'];
            end
        local Ref = A['Ref'];
            error_str = error_str .. wrap( 'parameter', selected );
    local DoiBroken = A['DoiBroken'];
            table.insert( z.message_tail, { seterror( error_condition, {error_str}, true ) } );
    local ID = A['ID'];
        end
        local ASINTLD = A['ASINTLD'];
        local IgnoreISBN = A['IgnoreISBN'];
        local Embargo = A['Embargo'];
     
        local ID_list = extractids( args );
          
          
         return value, selected;
         local Quote = A['Quote'];
    end
        local PostScript = A['PostScript'];


    -- COinS metadata (see <http://ocoins.info/>) allows automated tools to parse
        local LayURL = A['LayURL'];
    -- the citation information.
        local LaySource = A['LaySource'];
    function COinS(data)
        local Transcript = A['Transcript'];
         if 'table' ~= type(data) or nil == next(data) then
         local TranscriptURL = A['TranscriptURL']
            return '';
        local TranscriptURLorigin = A:ORIGIN('TranscriptURL');
        end
        local sepc = A['Separator'];
       
     
        local ctx_ver = "Z39.88-2004";
        local LastAuthorAmp = A['LastAuthorAmp'];
       
        local no_tracking_cats = A['NoTracking'];
         -- treat table strictly as an array with only set values.
     
         local OCinSoutput = setmetatable( {}, {
    --these are used by cite interview
            __newindex = function(self, key, value)
    local Callsign = A['Callsign'];
                if is_set(value) then
    local City = A['City'];
                    rawset( self, #self+1, table.concat{ key, '=', mw.uri.encode( removewikilink( value ) ) } );
    local Cointerviewers = A['Cointerviewers']; -- deprecated
    local Interviewer = A['Interviewer']; -- deprecated
    local Program = A['Program'];
     
    --local variables that are not cs1 parameters
         local page_type; -- is this needed?  Doesn't appear to be used anywhere;
         local use_lowercase = ( sepc ~= '.' );
        local this_page = mw.title.getCurrentTitle(); --Also used for COinS and for language
    local anchor_year; -- used in the CITEREF identifier
    local COinS_date; -- used in the COinS metadata
     
    -- Set postscript default.
    if not is_set (PostScript) then -- if |postscript= has not been set (Postscript is nil which is the default for {{citation}}) and
    if (config.CitationClass ~= "citation") then -- this template is not a citation template
    PostScript = '.'; -- must be a cite xxx template so set postscript to default (period)
    end
    else
    if PostScript:lower() == 'none' then -- if |postscript=none then
    PostScript = ''; -- no postscript
    end
    end
     
    --check this page to see if it is in one of the namespaces that cs1 is not supposed to add to the error categories.
    if not is_set(no_tracking_cats) then -- ignore if we are already not going to categorize this page
    for k, v in pairs( cfg.uncategorized_namespaces ) do -- otherwise, spin through the list of namespaces we don't include in error categories
    if this_page.nsText == v then -- if we find one
    no_tracking_cats = "true"; -- set no_trackin_cats
    break; -- and we're done
                 end
                 end
             end
             end
         });
         end
     
    -- check for extra |page=, |pages= or |at= parameters.
        if is_set(Page) then
            if is_set(Pages) or is_set(At) then
                Page = Page .. " " .. seterror('extra_pages'); -- add error message
                Pages = ''; -- unset the others
                At = '';
            end
        elseif is_set(Pages) then
            if is_set(At) then
                Pages = Pages .. " " .. seterror('extra_pages'); -- add error messages
                At = ''; -- unset
            end
        end   
     
    -- both |publication-place= and |place= (|location=) allowed if different
        if not is_set(PublicationPlace) and is_set(Place) then
            PublicationPlace = Place; -- promote |place= (|location=) to |publication-place
        end
          
          
         if is_set(data.Chapter) then
         if PublicationPlace == Place then Place = ''; end -- don't need both if they are the same
            OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
            OCinSoutput["rft.genre"] = "bookitem";
            OCinSoutput["rft.btitle"] = data.Chapter;
            OCinSoutput["rft.atitle"] = data.Title;
        elseif is_set(data.Periodical) then
            OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:journal";
            OCinSoutput["rft.genre"] = "article";
            OCinSoutput["rft.jtitle"] = data.Periodical;
            OCinSoutput["rft.atitle"] = data.Title;
        else
            OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
            OCinSoutput["rft.genre"] = "book"
            OCinSoutput["rft.btitle"] = data.Title;
        end
          
          
        OCinSoutput["rft.place"] = data.PublicationPlace;
    --[[
        OCinSoutput["rft.date"] = data.Date;
    Parameter remapping for cite encyclopedia:
        OCinSoutput["rft.series"] = data.Series;
    When the citation has these parameters:
        OCinSoutput["rft.volume"] = data.Volume;
    |encyclopedia and |title then map |title to |article and |encyclopedia to |title
        OCinSoutput["rft.issue"] = data.Issue;
    |encyclopedia and |article then map |encyclopedia to |title
        OCinSoutput["rft.pages"] = data.Pages;
    |encyclopedia then map |encyclopedia to |title
        OCinSoutput["rft.edition"] = data.Edition;
     
        OCinSoutput["rft.pub"] = data.PublisherName;
    |trans_title maps to |trans_chapter when |title is re-mapped
       
     
        for k, v in pairs( data.ID_list ) do
    All other combinations of |encyclopedia, |title, and |article are not modified
            local id, value = cfg.id_handlers[k].COinS;
    ]]
            if k == 'ISBN' then value = cleanisbn( v ); else value = v; end
    if ( config.CitationClass == "encyclopaedia" ) then
            if string.sub( id or "", 1, 4 ) == 'info' then
    if is_set(Periodical) then -- Periodical is set when |encyclopedia is set
                OCinSoutput["rft_id"] = table.concat{ id, "/", v };
    if is_set(Title) then
            else
    if not is_set(Chapter) then
                OCinSoutput[ id ] = value;
    Chapter = Title; -- |encyclopedia and |title are set so map |title to |article and |encyclopedia to |title
            end
    TransChapter = TransTitle;
        end
    Title = Periodical;
       
    Periodical = ''; -- redundant so unset
        local last, first;
    TransTitle = ''; -- redundant so unset
        for k, v in ipairs( data.Authors ) do
    end
            last, first = v.last, v.first;
    else -- |title not set
            if k == 1 then
    Title = Periodical; -- |encyclopedia set and |article set or not set so map |encyclopedia to |title
                if is_set(last) then
    Periodical = ''; -- redundant so unset
                    OCinSoutput["rft.aulast"] = last;
    end
                end
    end
                if is_set(first) then  
    end
                    OCinSoutput["rft.aufirst"] = first;
     
                end
    --special cases for citation.
            end
    if (config.CitationClass == "citation") then -- for citation templates
            if is_set(last) and is_set(first) then
    if not is_set (Ref) then -- if |ref= is not set
                OCinSoutput["rft.au"] = table.concat{ last, ", ", first };
    Ref = "harv"; -- set default |ref=harv
            elseif is_set(last) then
    end
                OCinSoutput["rft.au"] = last;
    if not is_set (sepc) then -- if |separator= is not set
            end
    sepc = ','; -- set citation separator to its default (comma)
        end
    end
       
    else -- not a citation template
        OCinSoutput.rft_id = data.URL;
    if not is_set (sepc) then -- if |separator= has not been set
        OCinSoutput.rfr_id = table.concat{ "info:sid/", mw.site.server:match( "[^/]*$" ), ":", data.RawPage };
    sepc = '.'; -- set cite xxx separator to its default (period)
        OCinSoutput = setmetatable( OCinSoutput, nil );
    end
       
    end
        -- sort with version string always first, and combine.
     
        table.sort( OCinSoutput );
    -- check for specital case where |separator=none
        table.insert( OCinSoutput, 1, "ctx_ver=" .. ctx_ver ); -- such as "Z39.88-2004"
    if 'none' == sepc:lower() then -- if |separator=none
        return table.concat(OCinSoutput, "&");
    sepc = ''; -- then set it to a empty string
    end
    end


    --[[
    -- Special case for cite techreport.
    This is the main function doing the majority of the citation
    if (config.CitationClass == "techreport") then -- special case for cite techreport
    formatting.
    if is_set(Issue) then -- cite techreport uses 'number', which other citations aliase to 'issue'
    ]]
    if not is_set(ID) then -- can we use ID for the "number"?
    function citation0( config, args)
    ID = Issue; -- yes, use it
        --[[
    Issue = ""; -- unset Issue so that "number" isn't duplicated in the rendered citation or COinS metadata
        Load Input Parameters
    else -- can't use ID so emit error message
        The argment_wrapper facillitates the mapping of multiple
    ID = ID .. " " .. seterror('redundant_parameters', '<code>&#124;id=</code> and <code>&#124;number=</code>');
        aliases to single internal variable.
    end
        ]]
    end
        local A = argument_wrapper( args );
    end
     
    -- special case for cite interview
    if (config.CitationClass == "interview") then
    if is_set(Program) then
    ID = ' ' .. Program;
    end
    if is_set(Callsign) then
    if is_set(ID) then
    ID = ID .. sepc .. ' ' .. Callsign;
    else
    ID = ' ' .. Callsign;
    end
    end
    if is_set(City) then
    if is_set(ID) then
    ID = ID .. sepc .. ' ' .. City;
    else
    ID = ' ' .. City;
    end
    end


        local i
    if is_set(Interviewer) then
        local PPrefix = A['PPrefix']
    if is_set(TitleType) then
        local PPPrefix = A['PPPrefix']
    Others = ' ' .. TitleType .. ' with ' .. Interviewer;
        if is_set( A['NoPP'] ) then PPPrefix = "" PPrefix = "" end
    TitleType = '';
       
    else
        -- Pick out the relevant fields from the arguments. Different citation templates
    Others = ' ' .. 'Interview with ' .. Interviewer;
        -- define different field names for the same underlying things.   
    end
        local Authors = A['Authors'];
    if is_set(Cointerviewers) then
        local a = extractnames( args, 'AuthorList' );
    Others = Others .. sepc .. ' ' .. Cointerviewers;
    end
    else
    Others = '(Interview)';
    end
    end
     
    --Account for the oddity that is {{cite journal}} with |pmc= set and |url= not set
    if config.CitationClass == "journal" and not is_set(URL) and is_set(ID_list['PMC']) then
    if not is_embargoed(Embargo) then
    URL=cfg.id_handlers['PMC'].prefix .. ID_list['PMC']; -- set url to be the same as the PMC external link if not embargoed
    URLorigin = cfg.id_handlers['PMC'].parameters[1]; -- set URLorigin to parameter name for use in error message if citation is missing a |title=
    end
    end


        local Coauthors = A['Coauthors'];
    -- Account for the oddity that is {{cite conference}}, before generation of COinS data.
        local Others = A['Others'];
    --TODO: if this is only for {{cite conference}}, shouldn't we be checking? (if config.CitationClass=='conference' then ...)
        local Editors = A['Editors'];
    if is_set(BookTitle) then
        local e = extractnames( args, 'EditorList' );
    Chapter = Title;
    ChapterLink = TitleLink;
    TransChapter = TransTitle;
    Title = BookTitle;
    TitleLink = '';
    TransTitle = '';
    end


        local Year = A['Year'];
    -- Account for the oddity that is {{cite episode}}, before generation of COinS data.
        local PublicationDate = A['PublicationDate'];
    --[[ -- {{cite episode}} is not currently supported by this module
        local OrigYear = A['OrigYear'];
    if config.CitationClass == "episode" then
        local Date = A['Date'];
    local AirDate = A['AirDate'];
        local LayDate = A['LayDate'];
    local SeriesLink = A['SeriesLink'];
        ------------------------------------------------- Get title data
    local Season = A['Season'];
        local Title = A['Title'];
    local SeriesNumber = A['SeriesNumber'];
        local BookTitle = A['BookTitle'];
    local Network = A['Network'];
        local Conference = A['Conference'];
    local Station = A['Station'];
        local TransTitle = A['TransTitle'];
    local s, n = {}, {};
        local TitleNote = A['TitleNote'];
    local Sep = (first_set(A["SeriesSeparator"], A["Separator"]) or "") .. " ";
        local TitleLink = A['TitleLink'];
        local Chapter = A['Chapter'];
    if is_set(Issue) then table.insert(s, cfg.messages["episode"] .. " " .. Issue); Issue = ''; end
        local ChapterLink = A['ChapterLink'];
    if is_set(Season) then table.insert(s, cfg.messages["season"] .. " " .. Season); end
        local TransChapter = A['TransChapter'];
    if is_set(SeriesNumber) then table.insert(s, cfg.messages["series"] .. " " .. SeriesNumber); end
        local TitleType = A['TitleType'];
    if is_set(Network) then table.insert(n, Network); end
        local Degree = A['Degree'];
    if is_set(Station) then table.insert(n, Station); end
        local Docket = A['Docket'];
        local ArchiveURL = A['ArchiveURL'];
    Date = Date or AirDate;
        local URL = A['URL']
    Chapter = Title;
        local URLorigin = A:ORIGIN('URL');
    ChapterLink = TitleLink;
        local ChapterURL = A['ChapterURL'];
    TransChapter = TransTitle;
        local ChapterURLorigin = A:ORIGIN('ChapterURL');
    Title = Series;
        local ConferenceURL = A['ConferenceURL'];
    TitleLink = SeriesLink;
        local ConferenceURLorigin = A:ORIGIN('ConferenceURL');
    TransTitle = '';
        local Periodical = A['Periodical'];
    Series = table.concat(s, Sep);
    ID = table.concat(n, Sep);
    end
    -- end of {{cite episode}} stuff]]


    --[[
    -- legacy: promote concatenation of |day=, |month=, and |year= to Date if Date not set; or, promote PublicationDate to Date if neither Date nor Year are set.
    Parameter remapping for cite encyclopedia:
    if not is_set(Date) then
    When the citation has these parameters:
    Date = Year; -- promote Year to Date
    |encyclopedia and |title then map |title to |article and |encyclopedia to |title
    Year = nil; -- make nil so Year as empty string isn't used for CITEREF
    |encyclopedia and |article then map |encyclopedia to |title
    if is_set(Date) then
    |encyclopedia then map |encyclopedia to |title
    local Month = A['Month'];
     
    if is_set(Month) then
    |trans_title maps to |trans_chapter when |title is re-mapped
    Date = Month .. " " .. Date;
     
    local Day = A['Day']
    All other combinations of |encyclopedia, |title, and |article are not modified
    if is_set(Day) then Date = Day .. " " .. Date end
    ]]
    if ( config.CitationClass == "encyclopaedia" ) then
    if is_set(Periodical) then -- Periodical is set when |encyclopedia is set
    if is_set(Title) then
    if not is_set(Chapter) then
    Chapter = Title; -- |encyclopedia and |title are set so map |title to |article and |encyclopedia to |title
    TransChapter = TransTitle;
    Title = Periodical;
    Periodical = ''; -- redundant so unset
    TransTitle = ''; -- redundant so unset
    end
    else -- |title not set
    Title = Periodical; -- |encyclopedia set and |article set or not set so map |encyclopedia to |title
    Periodical = ''; -- redundant so unset
    end
    end
    elseif is_set(PublicationDate) then -- use PublicationDate when |date= and |year= are not set
    Date = PublicationDate; -- promonte PublicationDate to Date
    PublicationDate = ''; -- unset, no longer needed
    end
    end
    end
    end


    local Series = A['Series'];
    if PublicationDate == Date then PublicationDate = ''; end -- if PublicationDate is same as Date, don't display in rendered citation
        local Volume = A['Volume'];
     
        local Issue = A['Issue'];
     
        local Position = '';
    --[[
        local Page, Pages, At, page_type;
    Go test all of the date-holding parameters for valid MOS:DATE format and make sure that dates are real dates. This must be done before we do COinS because here is where
       
    we get the date used in the metadata.
        Page = A['Page'];
     
        Pages = hyphentodash( A['Pages'] );
    Date validation supporting code is in Module:Citation/CS1/Date_validation
        At = A['At'];
    ]]
       
    anchor_year, COinS_date, error_message = dates({['accessdate']=AccessDate, ['airdate']=AirDate, ['archivedate']=ArchiveDate, ['date']=Date, ['doi_brokendate']=DoiBroken,
        if is_set(Page) then
    ['embargo']=Embargo, ['laydate']=LayDate, ['publicationdate']=PublicationDate, ['year']=Year});
            if is_set(Pages) or is_set(At) then
    if is_set(error_message) then
                Page = Page .. " " .. seterror('extra_pages');
    table.insert( z.message_tail, { seterror( 'bad_date', {error_message}, true ) } ); -- add this error message
                Pages = '';
    end
                At = '';
     
            end
    -- At this point fields may be nil if they weren't specified in the template use.  We can use that fact.
        elseif is_set(Pages) then
     
            if is_set(At) then
         -- COinS metadata (see <http://ocoins.info/>) for
                Pages = Pages .. " " .. seterror('extra_pages');
         -- automated parsing of citation information.
                At = '';
         local OCinSoutput = COinS{
            end
            ['Periodical'] = Periodical,
         end   
            ['Chapter'] = Chapter,
          
            ['Title'] = Title,
         local Edition = A['Edition'];
             ['PublicationPlace'] = PublicationPlace,
        local PublicationPlace = A['PublicationPlace']
            ['Date'] = first_set(COinS_date, Date), -- COinS_date has correctly formatted date if Date is valid; any reason to keep Date here?  Should we be including invalid dates in metadata?
        local Place = A['Place'];
            ['Series'] = Series,
       
            ['Volume'] = Volume,
        if not is_set(PublicationPlace) and is_set(Place) then
            ['Issue'] = Issue,
             PublicationPlace = Place;
            ['Pages'] = get_coins_pages (first_set(Page, Pages, At)), -- pages stripped of external links
        end
            ['Edition'] = Edition,
       
            ['PublisherName'] = PublisherName,
        if PublicationPlace == Place then Place = ''; end
            ['URL'] = first_set( URL, ChapterURL ),
       
            ['Authors'] = a,
        local PublisherName = A['PublisherName'];
            ['ID_list'] = ID_list,
        local RegistrationRequired = A['RegistrationRequired'];
            ['RawPage'] = this_page.prefixedText,
        local SubscriptionRequired = A['SubscriptionRequired'];
         };
        local Via = A['Via'];
        local AccessDate = A['AccessDate'];
        local ArchiveDate = A['ArchiveDate'];
        local Agency = A['Agency'];
        local DeadURL = A['DeadURL']
        local Language = A['Language'];
        local Format = A['Format'];
        local Ref = A['Ref'];
       
        local DoiBroken = A['DoiBroken'];
    -- Special case for cite techreport.
    local ID = A['ID'];
    if (config.CitationClass == "techreport") then -- special case for cite techreport
    if is_set(Issue) then -- cite techreport uses 'number', which other citations aliase to 'issue'
    if not is_set(ID) then -- can we use ID for the "number"?
    ID = Issue; -- yes, use it
    Issue = ""; -- unset Issue so that "number" isn't duplicated in the rendered citation or COinS metadata
    else -- can't use ID so emit error message
    ID = ID .. " " .. seterror('redundant_parameters', '<code>&#124;id=</code> and <code>&#124;number=</code>');
    end
    end
    end
        local ASINTLD = A['ASINTLD'];
        local IgnoreISBN = A['IgnoreISBN'];
         local Embargo = A['Embargo'];


         local ID_list = extractids( args );
         if is_set(Periodical) and not is_set(Chapter) and is_set(Title) then
       
            Chapter = Title;
        local Quote = A['Quote'];
            ChapterLink = TitleLink;
        local PostScript = A['PostScript'];
            TransChapter = TransTitle;
        local LayURL = A['LayURL'];
            Title = '';
        local LaySource = A['LaySource'];
            TitleLink = '';
        local Transcript = A['Transcript'];
            TransTitle = '';
        local TranscriptURL = A['TranscriptURL']
        local TranscriptURLorigin = A:ORIGIN('TranscriptURL');
        local sepc = A['Separator'];
        local LastAuthorAmp = A['LastAuthorAmp'];
        local no_tracking_cats = A['NoTracking'];
     
        local use_lowercase = ( sepc ~= '.' );
        local this_page = mw.title.getCurrentTitle();  --Also used for COinS and for language
       
        if not is_set(no_tracking_cats) then
            for k, v in pairs( cfg.uncategorized_namespaces ) do
                if this_page.nsText == v then
                    no_tracking_cats = "true";
                    break;
                end
            end
         end
         end


    local anchor_year; -- used in the CITEREF identifier
        -- Now perform various field substitutions.
    local COinS_date; -- used in the COinS metadata
        -- We also add leading spaces and surrounding markup and punctuation to the
     
        -- various parts of the citation, but only when they are non-nil.
    -- legacy: promote concatenation of |day=, |month=, and |year= to Date if Date not set; or, promote PublicationDate to Date if neither Date nor Year are set.
        if not is_set(Authors) then
    if not is_set(Date) then
            local Maximum = tonumber( A['DisplayAuthors'] );
    Date = Year; -- promote Year to Date
           
    Year = nil; -- make nil so Year as empty string isn't used for CITEREF
            -- Preserve old-style implicit et al.
    if is_set(Date) then
            if not is_set(Maximum) and #a == 9 then  
    local Month = A['Month'];
                Maximum = 8;
    if is_set(Month) then
                table.insert( z.message_tail, { seterror('implict_etal_author', {}, true ) } );
    Date = Month .. " " .. Date;
            elseif not is_set(Maximum) then
    local Day = A['Day']
                Maximum = #a + 1;
    if is_set(Day) then Date = Day .. " " .. Date end
            end
    end
               
    elseif is_set(PublicationDate) then -- use PublicationDate when |date= and |year= are not set
            local control = {
    Date = PublicationDate; -- promonte PublicationDate to Date
                sep = A["AuthorSeparator"] .. " ",
    PublicationDate = ''; -- unset, no longer needed
                namesep = (first_set(A["AuthorNameSeparator"], A["NameSeparator"]) or "") .. " ",
    end
                format = A["AuthorFormat"],
    end
                maximum = Maximum,
     
                lastauthoramp = LastAuthorAmp
    if PublicationDate == Date then PublicationDate = ''; end -- if PublicationDate is same as Date, don't display in rendered citation
            };
           
            -- If the coauthor field is also used, prevent ampersand and et al. formatting.
            if is_set(Coauthors) then
                control.lastauthoramp = nil;
                control.maximum = #a + 1;
            end
           
            Authors = listpeople(control, a)
        end


    -- Go test all of the date-holding parameters for valid MOS:DATE format and make sure that dates are real dates.
    if not is_set(Authors) and is_set(Coauthors) then -- coauthors aren't displayed if one of authors=, authorn=, or lastn= isn't specified
    -- TODO: 2013-10-27: AirDate is nil when dates() is called because it hasn't been set yet.  Move the call to dates() or set AirDate earlier.
    table.insert( z.message_tail, { seterror('coauthors_missing_author', {}, true) } ); -- emit error message
    anchor_year, COinS_date = dates({['accessdate']=AccessDate, ['airdate']=AirDate, ['archivedate']=ArchiveDate, ['date']=Date, ['doi_brokendate']=DoiBroken,
    ['embargo']=Embargo, ['laydate']=LayDate, ['publicationdate']=PublicationDate, ['year']=Year});
     
    -- At this point fields may be nil if they weren't specified in the template use.  We can use that fact.
     
    --Account for the oddity that is {{cite journal}} with |pmc= set and |url= not set
    if config.CitationClass == "journal" and not is_set(URL) and is_set(ID_list['PMC']) then
    if not is_embargoed(Embargo) then
    URL=cfg.id_handlers['PMC'].prefix .. ID_list['PMC']; -- set url to be the same as the PMC external link if not embargoed
    URLorigin = cfg.id_handlers['PMC'].parameters[1]; -- set URLorigin to parameter name for use in error message if citation is missing a |title=
    end
    end
    end


         -- Account for the oddity that is {{cite conference}}, before generation of COinS data.
         local EditorCount
         if is_set(BookTitle) then
         if not is_set(Editors) then
             Chapter = Title;
             local Maximum = tonumber( A['DisplayEditors'] );
             ChapterLink = TitleLink;
             -- Preserve old-style implicit et al.
             TransChapter = TransTitle;
            if not is_set(Maximum) and #e == 4 then
             Title = BookTitle;
                Maximum = 3;
             TitleLink = '';
                table.insert( z.message_tail, { seterror('implict_etal_editor', {}, true) } );
             TransTitle = '';
             elseif not is_set(Maximum) then
                Maximum = #e + 1;
             end
     
            local control = {
                sep = A["EditorSeparator"] .. " ",
                namesep = (first_set(A["EditorNameSeparator"], A["NameSeparator"]) or "") .. " ",
                format = A['EditorFormat'],
                maximum = Maximum,
                lastauthoramp = LastAuthorAmp
            };
     
             Editors, EditorCount = listpeople(control, e);
        else
             EditorCount = 1;
         end
         end
         -- Account for the oddity that is {{cite episode}}, before generation of COinS data.
     
         if config.CitationClass == "episode" then
        local Cartography = "";
             local AirDate = A['AirDate'];
         local Scale = "";
            local SeriesLink = A['SeriesLink'];
         if config.CitationClass == "map" then
            local Season = A['Season'];
             if not is_set( Authors ) and is_set( PublisherName ) then
             local SeriesNumber = A['SeriesNumber'];
                Authors = PublisherName;
             local Network = A['Network'];
                PublisherName = "";
            local Station = A['Station'];
             end
            local s, n = {}, {};
             Cartography = A['Cartography'];
            local Sep = (first_set(A["SeriesSeparator"], A["Separator"]) or "") .. " ";
             if is_set( Cartography ) then
           
                Cartography = sepc .. " " .. wrap( 'cartography', Cartography, use_lowercase );
             if is_set(Issue) then table.insert(s, cfg.messages["episode"] .. " " .. Issue); Issue = ''; end
            end      
             if is_set(Season) then table.insert(s, cfg.messages["season"] .. " " .. Season); end
             Scale = A['Scale'];
             if is_set(SeriesNumber) then table.insert(s, cfg.messages["series"] .. " " .. SeriesNumber); end
             if is_set( Scale ) then
            if is_set(Network) then table.insert(n, Network); end
                Scale = sepc .. " " .. Scale;
             if is_set(Station) then table.insert(n, Station); end
             end      
           
            Date = Date or AirDate;
            Chapter = Title;
            ChapterLink = TitleLink;
            TransChapter = TransTitle;
            Title = Series;
            TitleLink = SeriesLink;
            TransTitle = '';
           
            Series = table.concat(s, Sep);
            ID = table.concat(n, Sep);
         end
         end
          
          
         -- COinS metadata (see <http://ocoins.info/>) for
         if  not is_set(URL) and
        -- automated parsing of citation information.
             not is_set(ChapterURL) and
        local OCinSoutput = COinS{
             not is_set(ArchiveURL) and
            ['Periodical'] = Periodical,
            not is_set(ConferenceURL) and
            ['Chapter'] = Chapter,
            not is_set(TranscriptURL) then
            ['Title'] = Title,
              
            ['PublicationPlace'] = PublicationPlace,
             -- Test if cite web or cite podcast |url= is missing or empty
            ['Date'] = first_set(COinS_date, Date), -- COinS_date has correctly formatted date if Date is valid; any reason to keep Date here? Should we be including invalid dates in metadata?
    if inArray(config.CitationClass, {"web","podcast"}) then
            ['Series'] = Series,
    table.insert( z.message_tail, { seterror( 'cite_web_url', {}, true ) } );
            ['Volume'] = Volume,
    end
            ['Issue'] = Issue,
            ['Pages'] = first_set(Page, Pages, At),
             ['Edition'] = Edition,
            ['PublisherName'] = PublisherName,
            ['URL'] = first_set( URL, ChapterURL ),
             ['Authors'] = a,
            ['ID_list'] = ID_list,
            ['RawPage'] = this_page.prefixedText,
        };
     
        if is_set(Periodical) and not is_set(Chapter) and is_set(Title) then
             Chapter = Title;
            ChapterLink = TitleLink;
            TransChapter = TransTitle;
            Title = '';
            TitleLink = '';
             TransTitle = '';
        end
     
        -- Now perform various field substitutions.
        -- We also add leading spaces and surrounding markup and punctuation to the
        -- various parts of the citation, but only when they are non-nil.
        if not is_set(Authors) then
            local Maximum = tonumber( A['DisplayAuthors'] );
              
              
             -- Preserve old-style implicit et al.
             -- Test if accessdate is given without giving a URL
             if not is_set(Maximum) and #a == 9 then  
             if is_set(AccessDate) then
                Maximum = 8;
                 table.insert( z.message_tail, { seterror( 'accessdate_missing_url', {}, true ) } );
                 table.insert( z.message_tail, { seterror('implict_etal_author', {}, true ) } );
                 AccessDate = '';
            elseif not is_set(Maximum) then
                 Maximum = #a + 1;
             end
             end
               
            local control = {
                sep = A["AuthorSeparator"] .. " ",
                namesep = (first_set(A["AuthorNameSeparator"], A["NameSeparator"]) or "") .. " ",
                format = A["AuthorFormat"],
                maximum = Maximum,
                lastauthoramp = LastAuthorAmp
            };
              
              
             -- If the coauthor field is also used, prevent ampersand and et al. formatting.
             -- Test if format is given without giving a URL
             if is_set(Coauthors) then
             if is_set(Format) then
                 control.lastauthoramp = nil;
                 Format = Format .. seterror( 'format_missing_url' );
                control.maximum = #a + 1;
             end
             end
           
            Authors = listpeople(control, a)
         end
         end
     
       
    if not is_set(Authors) and is_set(Coauthors) then -- coauthors aren't displayed if one of authors=, authorn=, or lastn= isn't specified
        -- Test if citation has no title
    table.insert( z.message_tail, { seterror('coauthors_missing_author', {}, true) } ); -- emit error message
        if not is_set(Chapter) and
    end
            not is_set(Title) and
     
            not is_set(Periodical) and
         local EditorCount
            not is_set(Conference) and
         if not is_set(Editors) then
            not is_set(TransTitle) and
            local Maximum = tonumber( A['DisplayEditors'] );
            not is_set(TransChapter) then
            -- Preserve old-style implicit et al.
            table.insert( z.message_tail, { seterror( 'citation_missing_title', {}, true ) } );
             if not is_set(Maximum) and #e == 4 then  
        end
                 Maximum = 3;
          
                 table.insert( z.message_tail, { seterror('implict_etal_editor', {}, true) } );
         Format = is_set(Format) and " (" .. Format .. ")" or "";
            elseif not is_set(Maximum) then
       
                Maximum = #e + 1;
        local OriginalURL = URL
        DeadURL = DeadURL:lower();
        if is_set( ArchiveURL ) then
             if ( DeadURL ~= "no" ) then
                 URL = ArchiveURL
                 URLorigin = A:ORIGIN('ArchiveURL')
             end
             end
     
        end
             local control = {
       
                sep = A["EditorSeparator"] .. " ",
        -- Format chapter / article title
                namesep = (first_set(A["EditorNameSeparator"], A["NameSeparator"]) or "") .. " ",
        if is_set(Chapter) and is_set(ChapterLink) then
                format = A['EditorFormat'],
             Chapter = "[[" .. ChapterLink .. "|" .. Chapter .. "]]";
                maximum = Maximum,
        end
                lastauthoramp = LastAuthorAmp
        if is_set(Periodical) and is_set(Title) then
            };
            Chapter = wrap( 'italic-title', Chapter );
     
             TransChapter = wrap( 'trans-italic-title', TransChapter );
             Editors, EditorCount = listpeople(control, e);
         else
         else
             EditorCount = 1;
    Chapter = kern_quotes (Chapter); -- if necessary, separate chapter title's leading and trailing quote marks from Module provided quote marks
            Chapter = wrap( 'quoted-title', Chapter );
             TransChapter = wrap( 'trans-quoted-title', TransChapter );
         end
         end
     
          
         local Cartography = "";
         local TransError = ""
         local Scale = "";
         if is_set(TransChapter) then
         if config.CitationClass == "map" then
             if not is_set(Chapter) then
             if not is_set( Authors ) and is_set( PublisherName ) then
                 TransError = " " .. seterror( 'trans_missing_chapter' );
                 Authors = PublisherName;
            else
                 PublisherName = "";
                 TransChapter = " " .. TransChapter;
             end
             end
            Cartography = A['Cartography'];
            if is_set( Cartography ) then
                Cartography = sepc .. " " .. wrap( 'cartography', Cartography, use_lowercase );
            end       
            Scale = A['Scale'];
            if is_set( Scale ) then
                Scale = sepc .. " " .. Scale;
            end       
         end
         end
          
          
         if not is_set(URL) and
        Chapter = Chapter .. TransChapter;
             not is_set(ChapterURL) and
       
            not is_set(ArchiveURL) and
         if is_set(Chapter) then
            not is_set(ConferenceURL) and
             if not is_set(ChapterLink) then
            not is_set(TranscriptURL) then
                if is_set(ChapterURL) then
           
                    Chapter = externallink( ChapterURL, Chapter ) .. TransError;
            -- Test if cite web or cite podcast |url= is missing or empty
                    if not is_set(URL) then
    if inArray(config.CitationClass, {"web","podcast"}) then
                        Chapter = Chapter .. Format;
    table.insert( z.message_tail, { seterror( 'cite_web_url', {}, true ) } );
                        Format = "";
    end
                    end
              
                elseif is_set(URL) then
            -- Test if accessdate is given without giving a URL
                    Chapter = externallink( URL, Chapter ) .. TransError .. Format;
            if is_set(AccessDate) then
                    URL = "";
                 table.insert( z.message_tail, { seterror( 'accessdate_missing_url', {}, true ) } );
                    Format = "";
                AccessDate = '';
                else
             end
                    Chapter = Chapter .. TransError;
           
                end          
            -- Test if format is given without giving a URL
             elseif is_set(ChapterURL) then
            if is_set(Format) then
                 Chapter = Chapter .. " " .. externallink( ChapterURL, nil, ChapterURLorigin ) ..
                 Format = Format .. seterror( 'format_missing_url' );
                    TransError;
             else
                 Chapter = Chapter .. TransError;
             end
             end
            Chapter = Chapter .. sepc .. " " -- with end-space
        elseif is_set(ChapterURL) then
            Chapter = " " .. externallink( ChapterURL, nil, ChapterURLorigin ) .. sepc .. " ";
        end       
       
        -- Format main title.
        if is_set(TitleLink) and is_set(Title) then
            Title = "[[" .. TitleLink .. "|" .. Title .. "]]"
         end
         end
          
          
         -- Test if citation has no title
         if is_set(Periodical) then
         if  not is_set(Chapter) and
    Title = kern_quotes (Title); -- if necessary, separate title's leading and trailing quote marks from Module provided quote marks
            not is_set(Title) and
            Title = wrap( 'quoted-title', Title );
            not is_set(Periodical) and
            TransTitle = wrap( 'trans-quoted-title', TransTitle );
             not is_set(Conference) and
         elseif inArray(config.CitationClass, {"web","news","pressrelease","conference","podcast"}) and
             not is_set(TransTitle) and
                not is_set(Chapter) then
             not is_set(TransChapter) then
    Title = kern_quotes (Title); -- if necessary, separate title's leading and trailing quote marks from Module provided quote marks
             table.insert( z.message_tail, { seterror( 'citation_missing_title', {}, true ) } );
             Title = wrap( 'quoted-title', Title );
             TransTitle = wrap( 'trans-quoted-title', TransTitle );
        else
             Title = wrap( 'italic-title', Title );
             TransTitle = wrap( 'trans-italic-title', TransTitle );
         end
         end
          
          
         Format = is_set(Format) and " (" .. Format .. ")" or "";
         TransError = "";
        if is_set(TransTitle) then
            if not is_set(Title) then
                TransError = " " .. seterror( 'trans_missing_title' );
            else
                TransTitle = " " .. TransTitle;
            end
        end
       
        Title = Title .. TransTitle;
          
          
         local OriginalURL = URL
         if is_set(Title) then
        DeadURL = DeadURL:lower();
            if not is_set(TitleLink) and is_set(URL) then  
        if is_set( ArchiveURL ) then
                Title = externallink( URL, Title ) .. TransError .. Format     
            if ( DeadURL ~= "no" ) then
                URL = "";
                 URL = ArchiveURL
                 Format = "";
                 URLorigin = A:ORIGIN('ArchiveURL')
            else
                 Title = Title .. TransError;
             end
             end
         end
         end
          
          
        -- Format chapter / article title
         if is_set(Place) then
         if is_set(Chapter) and is_set(ChapterLink) then  
             Place = " " .. wrap( 'written', Place, use_lowercase ) .. sepc .. " ";
             Chapter = "[[" .. ChapterLink .. "|" .. Chapter .. "]]";
         end
         end
         if is_set(Periodical) and is_set(Title) then
       
            Chapter = wrap( 'italic-title', Chapter );
         if is_set(Conference) then
             TransChapter = wrap( 'trans-italic-title', TransChapter );
            if is_set(ConferenceURL) then
         else
                Conference = externallink( ConferenceURL, Conference );
    Chapter = kern_quotes (Chapter); -- if necessary, separate chapter title's leading and trailing quote marks from Module provided quote marks
             end
             Chapter = wrap( 'quoted-title', Chapter );
            Conference = sepc .. " " .. Conference
            TransChapter = wrap( 'trans-quoted-title', TransChapter );
         elseif is_set(ConferenceURL) then
             Conference = sepc .. " " .. externallink( ConferenceURL, nil, ConferenceURLorigin );
         end
         end
          
          
        local TransError = ""
         if not is_set(Position) then
         if is_set(TransChapter) then
            local Minutes = A['Minutes'];
             if not is_set(Chapter) then
             if is_set(Minutes) then
                 TransError = " " .. seterror( 'trans_missing_chapter' );
                 Position = " " .. Minutes .. " " .. cfg.messages['minutes'];
             else
             else
                 TransChapter = " " .. TransChapter;
                 local Time = A['Time'];
            end
                 if is_set(Time) then
        end
                     local TimeCaption = A['TimeCaption']
       
                     if not is_set(TimeCaption) then
        Chapter = Chapter .. TransChapter;
                         TimeCaption = cfg.messages['event'];
       
                         if sepc ~= '.' then
        if is_set(Chapter) then
                            TimeCaption = TimeCaption:lower();
            if not is_set(ChapterLink) then
                        end
                 if is_set(ChapterURL) then
                     Chapter = externallink( ChapterURL, Chapter ) .. TransError;
                     if not is_set(URL) then
                         Chapter = Chapter .. Format;
                         Format = "";
                     end
                     end
                elseif is_set(URL) then
                     Position = " " .. TimeCaption .. " " .. Time;
                    Chapter = externallink( URL, Chapter ) .. TransError .. Format;
                 end
                    URL = "";
                     Format = "";
                else
                    Chapter = Chapter .. TransError;
                end           
            elseif is_set(ChapterURL) then
                Chapter = Chapter .. " " .. externallink( ChapterURL, nil, ChapterURLorigin ) ..
                    TransError;
            else
                 Chapter = Chapter .. TransError;
             end
             end
            Chapter = Chapter .. sepc .. " " -- with end-space
         else
         elseif is_set(ChapterURL) then
             Position = " " .. Position;
             Chapter = " " .. externallink( ChapterURL, nil, ChapterURLorigin ) .. sepc .. " ";
            At = '';
         end      
         end
          
          
         -- Format main title.
         if not is_set(Page) then
         if is_set(TitleLink) and is_set(Title) then
            if is_set(Pages) then
            Title = "[[" .. TitleLink .. "|" .. Title .. "]]"
                if is_set(Periodical) and
                    not inArray(config.CitationClass, {"encyclopaedia","web","book","news","podcast"}) then
                    Pages = ": " .. Pages;
                elseif tonumber(Pages) ~= nil then
                    Pages = sepc .." " .. PPrefix .. Pages;
                else
                    Pages = sepc .." " .. PPPrefix .. Pages;
                end
            end
         else
            if is_set(Periodical) and
                not inArray(config.CitationClass, {"encyclopaedia","web","book","news","podcast"}) then
                Page = ": " .. Page;
            else
                Page = sepc .." " .. PPrefix .. Page;
            end
         end
         end
          
          
         if is_set(Periodical) then
         At = is_set(At) and (sepc .. " " .. At) or "";
    Title = kern_quotes (Title); -- if necessary, separate title's leading and trailing quote marks from Module provided quote marks
        Position = is_set(Position) and (sepc .. " " .. Position) or "";
            Title = wrap( 'quoted-title', Title );
         if config.CitationClass == 'map' then
            TransTitle = wrap( 'trans-quoted-title', TransTitle );
             local Section = A['Section'];
         elseif inArray(config.CitationClass, {"web","news","pressrelease","conference","podcast"}) and
             local Inset = A['Inset'];
                not is_set(Chapter) then
             if first_set( Pages, Page, At ) ~= nil or sepc ~= '.' then
    Title = kern_quotes (Title); -- if necessary, separate title's leading and trailing quote marks from Module provided quote marks
                if is_set( Section ) then
             Title = wrap( 'quoted-title', Title );
                    Section = ", " .. wrap( 'section', Section, true );
             TransTitle = wrap( 'trans-quoted-title', TransTitle );
                end
        else
                if is_set( Inset ) then
             Title = wrap( 'italic-title', Title );
                    Inset = ", " .. wrap( 'inset', Inset, true );
            TransTitle = wrap( 'trans-italic-title', TransTitle );
                end
        end
       
        TransError = "";
        if is_set(TransTitle) then
            if not is_set(Title) then
                TransError = " " .. seterror( 'trans_missing_title' );
             else
             else
                 TransTitle = " " .. TransTitle;
                 if is_set( Section ) then
            end
                    Section = sepc .. " " .. wrap( 'section', Section, use_lowercase );
        end
                    if is_set( Inset ) then
       
                        Inset = ", " .. wrap( 'inset', Inset, true );
        Title = Title .. TransTitle;
                    end
          
                elseif is_set( Inset ) then
        if is_set(Title) then
                    Inset = sepc .. " " .. wrap( 'inset', Inset, use_lowercase );
            if not is_set(TitleLink) and is_set(URL) then  
                end          
                Title = externallink( URL, Title ) .. TransError .. Format     
            end           
                URL = "";
            At = At .. Section .. Inset;      
                Format = "";
         end   
            else
     
                Title = Title .. TransError;
    --[[Look in the list of iso639-1 language codes to see if the value provided in the language parameter matches one of them.  If a match is found,
            end
    use that value; if not, then use the value that was provided with the language parameter.
        end
       
    Categories are assigned in a manner similar to the {{xx icon}} templates - categorizes only mainspace citations and only when the language code is not 'en' (English).
        if is_set(Place) then
    ]]
            Place = " " .. wrap( 'written', Place, use_lowercase ) .. sepc .. " ";
    if is_set (Language) then
        end
    -- local name = mw.language.fetchLanguageName( Language:lower(), "en" ); -- experiment: this seems to return correct ISO 639-1 language names
       
    local name = cfg.iso639_1[Language:lower()]; -- get the language name if Language parameter has a valid iso 639-1 code
        if is_set(Conference) then
    if nil == name then
            if is_set(ConferenceURL) then
    Language=" " .. wrap( 'language', Language ); -- no match, use parameter's value
                Conference = externallink( ConferenceURL, Conference );
    else
            end
    if 0 == this_page.namespace and 'en' ~= Language:lower() then --found a match; is this page main / article space and English not the language?
            Conference = sepc .. " " .. Conference
    Language=" " .. wrap( 'language', name .. '[[Category:Articles with ' .. name .. '-language external links]]' ); -- in main space and not English: categorize
         elseif is_set(ConferenceURL) then
    else
            Conference = sepc .. " " .. externallink( ConferenceURL, nil, ConferenceURLorigin );
    Language=" " .. wrap( 'language', name ); --not in mainspace or language is English so don't categorize
        end
    end
       
    end
         if not is_set(Position) then
    else
            local Minutes = A['Minutes'];
    Language=""; -- language not specified so make sure this is an empty string;
             if is_set(Minutes) then
    end
                Position = " " .. Minutes .. " " .. cfg.messages['minutes'];
     
             else
    Others = is_set(Others) and (sepc .. " " .. Others) or "";
                local Time = A['Time'];
     
                if is_set(Time) then
    -- handle type parameter for those CS1 citations that have default values
                    local TimeCaption = A['TimeCaption']
     
                    if not is_set(TimeCaption) then
    if inArray(config.CitationClass, {"AV media notes", "DVD notes", "podcast", "pressrelease", "techreport", "thesis"}) then
                        TimeCaption = cfg.messages['event'];
    TitleType = set_titletype (config.CitationClass, TitleType);
                        if sepc ~= '.' then
    if is_set(Degree) and "Thesis" == TitleType then -- special case for cite thesis
                            TimeCaption = TimeCaption:lower();
    TitleType = Degree .. " thesis";
                        end
    end
                    end
    end
                    Position = " " .. TimeCaption .. " " .. Time;
     
                end
    if is_set(TitleType) then -- if type parameter is specified
    TitleType = " (" .. TitleType .. ")"; -- display it in parentheses
    end
     
    TitleNote = is_set(TitleNote) and (sepc .. " " .. TitleNote) or "";
        Edition = is_set(Edition) and (" " .. wrap( 'edition', Edition )) or "";
        Issue = is_set(Issue) and (" (" .. Issue .. ")") or "";
        Series = is_set(Series) and (sepc .. " " .. Series) or "";
         OrigYear = is_set(OrigYear) and (" [" .. OrigYear .. "]") or "";
        Agency = is_set(Agency) and (sepc .. " " .. Agency) or "";
     
         if is_set(Volume) then
             if ( mw.ustring.len(Volume) > 4 )
              then Volume = sepc .." " .. Volume;
              else Volume = " <b>" .. hyphentodash(Volume) .. "</b>";
             end
        end
     
    --[[ This code commented out while discussion continues until after week of 2014-03-23 live module update;
        if is_set(Volume) then
            if ( mw.ustring.len(Volume) > 4 )
              then Volume = sepc .. " " .. Volume;
              else
                  Volume = " <b>" .. hyphentodash(Volume) .. "</b>";
                  if is_set(Series) then Volume = sepc .. Volume;
                  end
             end
             end
        else
            Position = " " .. Position;
            At = '';
         end
         end
    ]]   
        ------------------------------------ totally unrelated data
        --[[ Loosely mimic {{subscription required}} template; Via parameter identifies a delivery source that is not the publisher; these sources often, but not always, exist
        behind a registration or paywall.  So here, we've chosen to decouple via from subscription (via has never been part of the registration required template).
          
          
         if not is_set(Page) then
         Subscription implies paywall; Registration does not.  If both are used in a citation, the subscription required link note is displayed. There are no error messages for this condition.
            if is_set(Pages) then
        ]]
                if is_set(Periodical) and
        if is_set(Via) then
                    not inArray(config.CitationClass, {"encyclopaedia","web","book","news","podcast"}) then
            Via = " " .. wrap( 'via', Via );
                    Pages = ": " .. Pages;
        end
                elseif tonumber(Pages) ~= nil then
     
                    Pages = sepc .." " .. PPrefix .. Pages;
    if is_set(SubscriptionRequired) then
                else
            SubscriptionRequired = sepc .. " " .. cfg.messages['subscription']; --here when 'via' parameter not used but 'subscription' is
                    Pages = sepc .." " .. PPPrefix .. Pages;
         elseif is_set(RegistrationRequired) then
                end
             SubscriptionRequired = sepc .. " " .. cfg.messages['registration']; --here when 'via' and 'subscription' parameters not used but 'registration' is
            end
         else
            if is_set(Periodical) and
                not inArray(config.CitationClass, {"encyclopaedia","web","book","news","podcast"}) then
                Page = ": " .. Page;
             else
                Page = sepc .." " .. PPrefix .. Page;
            end
         end
         end
       
        At = is_set(At) and (sepc .. " " .. At) or "";
        Position = is_set(Position) and (sepc .. " " .. Position) or "";
        if config.CitationClass == 'map' then
            local Section = A['Section'];
            local Inset = A['Inset'];
            if first_set( Pages, Page, At ) ~= nil or sepc ~= '.' then
                if is_set( Section ) then
                    Section = ", " .. wrap( 'section', Section, true );
                end
                if is_set( Inset ) then
                    Inset = ", " .. wrap( 'inset', Inset, true );
                end
            else
                if is_set( Section ) then
                    Section = sepc .. " " .. wrap( 'section', Section, use_lowercase );
                    if is_set( Inset ) then
                        Inset = ", " .. wrap( 'inset', Inset, true );
                    end
                elseif is_set( Inset ) then
                    Inset = sepc .. " " .. wrap( 'inset', Inset, use_lowercase );
                end           
            end           
            At = At .. Section .. Inset;       
        end   


    --[[Look in the list of iso639-1 language codes to see if the value provided in the language parameter matches one of them.  If a match is found,
        if is_set(AccessDate) then
    use that value; if not, then use the value that was provided with the language parameter.
            local retrv_text = " " .. cfg.messages['retrieved']
            if (sepc ~= ".") then retrv_text = retrv_text:lower() end
    Categories are assigned in a manner similar to the {{xx icon}} templates - categorizes only mainspace citations and only when the language code is not 'en' (English).
            AccessDate = '<span class="reference-accessdate">' .. sepc
    ]]
                .. substitute( retrv_text, {AccessDate} ) .. '</span>'
    if is_set (Language) then
        end
    -- local name = mw.language.fetchLanguageName( Language:lower(), "en" ); -- experiment: this seems to return correct ISO 639-1 language names
       
    local name = cfg.iso639_1[Language:lower()]; -- get the language name if Language parameter has a valid iso 639-1 code
        if is_set(ID) then ID = sepc .." ".. ID; end
    if nil == name then
      if "thesis" == config.CitationClass and is_set(Docket) then
    Language=" " .. wrap( 'language', Language ); -- no match, use parameter's value
    ID = sepc .." Docket ".. Docket .. ID;
    else
    if 0 == this_page.namespace and 'en' ~= Language:lower() then --found a match; is this page main / article space and English not the language?
    Language=" " .. wrap( 'language', name .. '[[Category:Articles with ' .. name .. '-language external links]]' ); -- in main space and not English: categorize
    else
    Language=" " .. wrap( 'language', name ); --not in mainspace or language is English so don't categorize
    end
    end
    else
    Language=""; -- language not specified so make sure this is an empty string;
    end
    end


    Others = is_set(Others) and (sepc .. " " .. Others) or "";
       
        ID_list = buildidlist( ID_list, {DoiBroken = DoiBroken, ASINTLD = ASINTLD, IgnoreISBN = IgnoreISBN, Embargo=Embargo} );


    -- handle type parameter for those CS1 citations that have default values
        if is_set(URL) then
            URL = " " .. externallink( URL, nil, URLorigin );
        end


    if inArray(config.CitationClass, {"podcast","pressrelease","techreport","thesis"}) then
        if is_set(Quote) then
    TitleType = set_titletype (config.CitationClass, TitleType);
            if Quote:sub(1,1) == '"' and Quote:sub(-1,-1) == '"' then
    if is_set(Degree) and "Thesis" == TitleType then -- special case for cite thesis
                Quote = Quote:sub(2,-2);
    TitleType = Degree .. " thesis";
    end
    end
     
    if is_set(TitleType) then -- if type parameter is specified
    TitleType = " (" .. TitleType .. ")"; -- display it in parentheses
    end
     
    TitleNote = is_set(TitleNote) and (sepc .. " " .. TitleNote) or "";
        Edition = is_set(Edition) and (" " .. wrap( 'edition', Edition )) or "";
        Issue = is_set(Issue) and (" (" .. Issue .. ")") or "";
        Series = is_set(Series) and (sepc .. " " .. Series) or "";
        OrigYear = is_set(OrigYear) and (" [" .. OrigYear .. "]") or "";
        Agency = is_set(Agency) and (sepc .. " " .. Agency) or "";
       
        if is_set(Volume) then
            if ( mw.ustring.len(Volume) > 4 )
              then Volume = sepc .." " .. Volume;
              else Volume = " <b>" .. hyphentodash(Volume) .. "</b>";
             end
             end
            Quote = sepc .." " .. wrap( 'quoted-text', Quote );
            PostScript = ""; -- CS1 does not supply terminal punctuation when |quote= is set
         end
         end
          
          
        ------------------------------------ totally unrelated data
         local Archived
        --[[ Loosely mimic {{subscription required}} template; Via parameter identifies a delivery source that is not the publisher; these sources often, but not always, exist
         if is_set(ArchiveURL) then
        behind a registration or paywall.  So here, we've chosen to decouple via from subscription (via has never been part of the registration required template).
       
        Subscription implies paywall; Registration does not.  If both are used in a citation, the subscription required link note is displayed. There are no error messages for this condition.
        ]]
        if is_set(Via) then
            Via = " " .. wrap( 'via', Via );
        end
     
    if is_set(SubscriptionRequired) then
            SubscriptionRequired = sepc .. " " .. cfg.messages['subscription']; --here when 'via' parameter not used but 'subscription' is
        elseif is_set(RegistrationRequired) then
            SubscriptionRequired = sepc .. " " .. cfg.messages['registration']; --here when 'via' and 'subscription' parameters not used but 'registration' is
        end
     
        if is_set(AccessDate) then
            local retrv_text = " " .. cfg.messages['retrieved']
            if (sepc ~= ".") then retrv_text = retrv_text:lower() end
            AccessDate = '<span class="reference-accessdate">' .. sepc
                .. substitute( retrv_text, {AccessDate} ) .. '</span>'
        end
       
        if is_set(ID) then ID = sepc .." ".. ID; end
      if "thesis" == config.CitationClass and is_set(Docket) then
    ID = sepc .." Docket ".. Docket .. ID;
    end
     
       
        ID_list = buildidlist( ID_list, {DoiBroken = DoiBroken, ASINTLD = ASINTLD, IgnoreISBN = IgnoreISBN, Embargo=Embargo} );
     
        if is_set(URL) then
            URL = " " .. externallink( URL, nil, URLorigin );
        end
     
        if is_set(Quote) then
            if Quote:sub(1,1) == '"' and Quote:sub(-1,-1) == '"' then
                Quote = Quote:sub(2,-2);
            end
            Quote = sepc .." " .. wrap( 'quoted-text', Quote );
            PostScript = "";
        elseif PostScript:lower() == "none" then
            PostScript = "";
        end
       
         local Archived
         if is_set(ArchiveURL) then
             if not is_set(ArchiveDate) then
             if not is_set(ArchiveDate) then
                 ArchiveDate = seterror('archive_missing_date');
                 ArchiveDate = seterror('archive_missing_date');
    Line 2,009: Line 1,973:
         end
         end
          
          
        if is_set(PostScript) and PostScript ~= sepc then
    if is_set(PostScript) and PostScript ~= sepc then
            text = safejoin( {text, sepc}, sepc );  --Deals with italics, spaces, etc.
    text = safejoin( {text, sepc}, sepc );  --Deals with italics, spaces, etc.
            text = text:sub(1,-2); --Remove final seperator   
    text = text:sub(1,-sepc:len()-1);
        end     
    -- text = text:sub(1,-2); --Remove final separator (assumes that sepc is only one character)
    end     
          
          
         text = safejoin( {text, PostScript}, sepc );
         text = safejoin( {text, PostScript}, sepc );
    Line 2,091: Line 2,056:
         local pframe = frame:getParent()
         local pframe = frame:getParent()
          
          
        if nil ~= string.find( frame:getTitle(), 'sandbox', 1, true ) then -- did the {{#invoke:}} use sandbox version?
        cfg = mw.loadData( 'Module:Citation/CS1/Configuration/sandbox' ); -- load sandbox versions of Configuration and Whitelist and ...
        whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist/sandbox' );
        dates = require('Module:Citation/CS1/Date_validation/sandbox').dates -- ... sandbox version of date validation code
        else -- otherwise
        cfg = mw.loadData( 'Module:Citation/CS1/Configuration' ); -- load live versions of Configuration and Whitelist and ...
        whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist' );
        dates = require('Module:Citation/CS1/Date_validation').dates -- ... live version of date validation code
    end
         local args = {};
         local args = {};
         local suggestions = {};
         local suggestions = {};

    Revision as of 12:26, 30 March 2014

    Documentation for this module may be created at Module:Citation/CS1/doc

    local z = {
        error_categories = {};
        error_ids = {};
        message_tail = {};
    }
    
    -- Include translation message hooks, ID and error handling configuration settings.
    --local cfg = mw.loadData( 'Module:Citation/CS1/Configuration/sandbox' );
    
    -- Contains a list of all recognized parameters
    --local whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist/sandbox' );
    
    --local dates = require('Module:Citation/CS1/Date_validation/sandbox').dates		-- location of date validation code
    
    -- Whether variable is set or not
    function is_set( var )
        return not (var == nil or var == '');
    end
    
    -- First set variable or nil if none
    function first_set(...)
        local list = {...};
        for _, var in pairs(list) do
            if is_set( var ) then
                return var;
            end
        end
    end
    
    -- Whether needle is in haystack
    function inArray( needle, haystack )
        if needle == nil then
            return false;
        end
        for n,v in ipairs( haystack ) do
            if v == needle then
                return n;
            end
        end
        return false;
    end
    
    --[[
    Categorize and emit an error message when the citation contains one or more deprecated parameters.  Because deprecated parameters (currently |day=, |month=,
    |coauthor=, and |coauthors=) aren't related to each other and because these parameters may be concatenated into the variables used by |date= and |author#= (and aliases)
    details of which parameter caused the error message are not provided.  Only one error message is emitted regarless of the number of deprecated parameters in the citation.
    ]]
    function deprecated_parameter()
    	if true ~= Page_in_deprecated_cat then	-- if we haven't been here before then set a 
    		Page_in_deprecated_cat=true;		-- sticky flag so that if there are more than one deprecated parameter the category is added only once
    --		table.insert( z.message_tail, { seterror( 'deprecated_params', {error_message}, true ) } );		-- add error message
    		table.insert( z.message_tail, { seterror( 'deprecated_params', {}, true ) } );		-- add error message
    	end
    end
    
    -- Populates numbered arguments in a message string using an argument table.
    function substitute( msg, args )
    --	return args and tostring( mw.message.newRawMessage( msg, args ) ) or msg;
    	return args and mw.message.newRawMessage( msg, args ):plain() or msg;
    end
    
    --[[
    Apply kerning to open the space between the quote mark provided by the Module and a leading or trailing quote mark contained in a |title= or |chapter= parameter's value.
    This function will positive kern  either single or double quotes:
    	"'Unkerned title with leading and trailing single quote marks'"
    	" 'Kerned title with leading and trailing single quote marks' " (in real life the kerning isn't as wide as this example)
    ]]
    function kern_quotes (str)
    	local left='<span style="padding-left:0.2em;">%1</span>';		-- spacing to use when title contains leading single or double quote mark
    	local right='<span style="padding-right:0.2em;">%1</span>';		-- spacing to use when title contains trailing single or double quote mark
    	
    	if  str:match ("^[\"\'][^\']") then
    		str = string.gsub( str, "^[\"\']", left, 1 );				-- replace (captured) leading single or double quote with left-side <span>
    	end
    	if str:match ("[^\'][\"\']$") then
    		str = string.gsub( str, "[\"\']$", right, 1 );			-- replace (captured) trailing single or double quote with right-side <span>
    	end
    	return str;
    end
    
    -- Wraps a string using a message_list configuration taking one argument
    function wrap( key, str, lower )
        if not is_set( str ) then
            return "";
        elseif inArray( key, { 'italic-title', 'trans-italic-title' } ) then
            str = safeforitalics( str );
        end
        if lower == true then
            return substitute( cfg.messages[key]:lower(), {str} );
        else
            return substitute( cfg.messages[key], {str} );
        end        
    end
    
    --[[
    Argument wrapper.  This function provides support for argument 
    mapping defined in the configuration file so that multiple names
    can be transparently aliased to single internal variable.
    ]]
    function argument_wrapper( args )
        local origin = {};
        
        return setmetatable({
            ORIGIN = function( self, k )
                local dummy = self[k]; --force the variable to be loaded.
                return origin[k];
            end
        },
        {
            __index = function ( tbl, k )
                if origin[k] ~= nil then
                    return nil;
                end
                
                local args, list, v = args, cfg.aliases[k];
                
                if type( list ) == 'table' then
                    v, origin[k] = selectone( args, list, 'redundant_parameters' );
                    if origin[k] == nil then
                        origin[k] = ''; -- Empty string, not nil
                    end
                elseif list ~= nil then
                    v, origin[k] = args[list], list;
                else
                    -- maybe let through instead of raising an error?
                    -- v, origin[k] = args[k], k;
                    error( cfg.messages['unknown_argument_map'] );
                end
                
                -- Empty strings, not nil;
                if v == nil then
                    v = cfg.defaults[k] or '';
                    origin[k] = '';
                end
                
                tbl = rawset( tbl, k, v );
                return v;
            end,
        });
    end
    
    --[[
    Looks for a parameter's name in the whitelist.
    
    Parameters in the whitelist can have three values:
    	true - active, supported parameters
    	false - deprecated, supported parameters
    	nil - unsupported parameters
    ]]
    function validate( name )
    	local name = tostring( name );
    	local state = whitelist.basic_arguments[ name ];
    	
    	-- Normal arguments
    	if true == state then return true; end		-- valid actively supported parameter
    	if false == state then
    		deprecated_parameter ();				-- parameter is deprecated but still supported
    		return true;
    	end
    	
    	-- Arguments with numbers in them
    	name = name:gsub( "%d+", "#" );				-- replace digit(s) with # (last25 becomes last#
    	state = whitelist.numbered_arguments[ name ];
    	if true == state then return true; end		-- valid actively supported parameter
    	if false == state then
    		deprecated_parameter ();				-- parameter is deprecated but still supported
    		return true;
    	end
    	
    	return false;								-- Not supported because not found or name is set to nil
    end
    
    -- Formats a comment for error trapping
    function errorcomment( content, hidden )
        return wrap( hidden and 'hidden-error' or 'visible-error', content );
    end
    
    --[[
    Sets an error condition and returns the appropriate error message.  The actual placement
    of the error message in the output is the responsibility of the calling function.
    ]]
    function seterror( error_id, arguments, raw, prefix, suffix )
        local error_state = cfg.error_conditions[ error_id ];
        
        prefix = prefix or "";
        suffix = suffix or "";
        
        if error_state == nil then
            error( cfg.messages['undefined_error'] );
        elseif is_set( error_state.category ) then
            table.insert( z.error_categories, error_state.category );
        end
        
        local message = substitute( error_state.message, arguments );
        
        message = message .. " ([[" .. cfg.messages['help page link'] .. 
            "#" .. error_state.anchor .. "|" ..
            cfg.messages['help page label'] .. "]])";
        
        z.error_ids[ error_id ] = true;
        if inArray( error_id, { 'bare_url_missing_title', 'trans_missing_title' } )
                and z.error_ids['citation_missing_title'] then
            return '', false;
        end
        
        message = table.concat({ prefix, message, suffix });
        
        if raw == true then
            return message, error_state.hidden;
        end        
            
        return errorcomment( message, error_state.hidden );
    end
    
    -- Formats a wiki style external link
    function externallinkid(options)
        local url_string = options.id;
        if options.encode == true or options.encode == nil then
            url_string = mw.uri.encode( url_string );
        end
        return mw.ustring.format( '[[%s|%s]]%s[%s%s%s %s]',
            options.link, options.label, options.separator or "&nbsp;",
            options.prefix, url_string, options.suffix or "",
            mw.text.nowiki(options.id)
        );
    end
    
    -- Formats a wiki style internal link
    function internallinkid(options)
        return mw.ustring.format( '[[%s|%s]]%s[[%s%s%s|%s]]',
            options.link, options.label, options.separator or "&nbsp;",
            options.prefix, options.id, options.suffix or "",
            mw.text.nowiki(options.id)
        );
    end
    
    -- Format an external link with error checking
    function externallink( URL, label, source )
        local error_str = "";
        if not is_set( label ) then
            label = URL;
            if is_set( source ) then
                error_str = seterror( 'bare_url_missing_title', { wrap( 'parameter', source ) }, false, " " );
            else
                error( cfg.messages["bare_url_no_origin"] );
            end            
        end
        if not checkurl( URL ) then
            error_str = seterror( 'bad_url', {}, false, " " ) .. error_str;
        end
        return table.concat({ "[", URL, " ", safeforurl( label ), "]", error_str });
    end
    
    -- Formats a link to Amazon
    function amazon(id, domain)
        if not is_set(domain) then 
            domain = "com"
        elseif ( "jp" == domain or "uk" == domain ) then
            domain = "co." .. domain
        end
        local handler = cfg.id_handlers['ASIN'];
        return externallinkid({link = handler.link,
            label=handler.label , prefix="//www.amazon."..domain.."/dp/",id=id,
            encode=handler.encode, separator = handler.separator})
    end
    
    --[[
    Format LCCN link and do simple error checking.  LCCN is a character string 8-12 characters long. The length of the LCCN dictates the character type of the first 1-3 characters; the
    rightmost eight are always digits. http://info-uri.info/registry/OAIHandler?verb=GetRecord&metadataPrefix=reg&identifier=info:lccn/
    
    length = 8 then all digits
    length = 9 then lccn[1] is alpha
    length = 10 then lccn[1] and lccn[2] are both alpha or both digits
    length = 11 then lccn[1] is alpha, lccn[2] and lccn[3] are both alpha or both digits
    length = 12 then lccn[1] and lccn[2] are both alpha
    
    ]]
    function lccn(id)
    	local handler = cfg.id_handlers['LCCN'];
    	local err_cat =  '';								-- presume that LCCN is valid
    
    	local len = id:len();								-- get the length of the lccn
    
    	if 8 == len then
    		if id:match("[^%d]") then						-- if LCCN has anything but digits (nil if only digits)
    			err_cat = ' ' .. seterror( 'bad_lccn' );	-- set an error message
    		end
    	elseif 9 == len then								-- LCCN should be adddddddd
    		if nil == id:match("%a%d%d%d%d%d%d%d%d") then			-- does it match our pattern?
    			err_cat = ' ' .. seterror( 'bad_lccn' );	-- set an error message
    		end
    	elseif 10 == len then								-- LCCN should be aadddddddd or dddddddddd
    		if id:match("[^%d]") then							-- if LCCN has anything but digits (nil if only digits) ...
    			if nil == id:match("^%a%a%d%d%d%d%d%d%d%d") then	-- ... see if it matches our pattern
    				err_cat = ' ' .. seterror( 'bad_lccn' );	-- no match, set an error message
    			end
    		end
    	elseif 11 == len then								-- LCCN should be aaadddddddd or adddddddddd
    		if not (id:match("^%a%a%a%d%d%d%d%d%d%d%d") or id:match("^%a%d%d%d%d%d%d%d%d%d%d")) then	-- see if it matches one of our patterns
    			err_cat = ' ' .. seterror( 'bad_lccn' );	-- no match, set an error message
    		end
    	elseif 12 == len then								-- LCCN should be aadddddddddd
    		if not id:match("^%a%a%d%d%d%d%d%d%d%d%d%d") then	-- see if it matches our pattern
    			err_cat = ' ' .. seterror( 'bad_lccn' );	-- no match, set an error message
    		end
    	else
    		err_cat = ' ' .. seterror( 'bad_lccn' );		-- wrong length, set an error message
    	end
    
    	return externallinkid({link = handler.link, label = handler.label,
    			prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    
    --[[
    Format PMID and do simple error checking.  PMIDs are sequential numbers beginning at 1 and counting up.  This code checks the PMID to see that it
    contains only digits and is less than test_limit; the value in local variable test_limit will need to be updated periodically as more PMIDs are issued.
    ]]
    function pmid(id)
    	local test_limit = 30000000;						-- update this value as PMIDs approach
    	local handler = cfg.id_handlers['PMID'];
    	local err_cat =  '';								-- presume that PMID is valid
    	
    	if id:match("[^%d]") then							-- if PMID has anything but digits
    		err_cat = ' ' .. seterror( 'bad_pmid' );		-- set an error message
    	else												-- PMID is only digits
    		local id_num = tonumber(id);					-- convert id to a number for range testing
    		if 1 > id_num or test_limit < id_num then		-- if PMID is outside test limit boundaries
    			err_cat = ' ' .. seterror( 'bad_pmid' );	-- set an error message
    		end
    	end
    	
    	return externallinkid({link = handler.link, label = handler.label,
    			prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    
    --[[
    Determines if a PMC identifier's online version is embargoed. Compares the date in |embargo= against today's date.  If embargo date is
    in the future, returns true; otherwse, returns false because the embargo has expired or |embargo= not set in this cite.
    ]]
    function is_embargoed(embargo)
    	if is_set(embargo) then
    		local lang = mw.getContentLanguage();
    		local good1, embargo_date, good2, todays_date;
    		good1, embargo_date = pcall( lang.formatDate, lang, 'U', embargo );
    		good2, todays_date = pcall( lang.formatDate, lang, 'U' );
    	
    		if good1 and good2 and tonumber( embargo_date ) >= tonumber( todays_date ) then	--is embargo date is in the future?
    			return true;	-- still embargoed
    		end
    	end
    	return false;			-- embargo expired or |embargo= not set
    end
    
    --[[
    Format a PMC, do simple error checking, and check for embargoed articles.
    
    The embargo parameter takes a date for a value. If the embargo date is in the future
    the PMC identifier will not be linked to the article.  If the embargo specifies a date in the past, or if it is empty or omitted, then
    the PMC identifier is linked to the article through the link at cfg.id_handlers['PMC'].prefix.
    
    PMCs are sequential numbers beginning at 1 and counting up.  This code checks the PMC to see that it contains only digits and is less
    than test_limit; the value in local variable test_limit will need to be updated periodically as more PMCs are issued.
    ]]
    function pmc(id, embargo)
    	local test_limit = 5000000;							-- update this value as PMCs approach
    	local handler = cfg.id_handlers['PMC'];
    	local err_cat =  '';								-- presume that PMC is valid
        
    	local text;
    
    	if id:match("[^%d]") then							-- if PMC has anything but digits
    		err_cat = ' ' .. seterror( 'bad_pmc' );			-- set an error message
    	else												-- PMC is only digits
    		local id_num = tonumber(id);					-- convert id to a number for range testing
    		if 1 > id_num or test_limit < id_num then		-- if PMC is outside test limit boundaries
    			err_cat = ' ' .. seterror( 'bad_pmc' );		-- set an error message
    		end
    	end
    	
    	if is_embargoed(embargo) then
    		text="[[" .. handler.link .. "|" .. handler.label .. "]]:" .. handler.separator .. id .. err_cat;	--still embargoed so no external link
    	else
    		text = externallinkid({link = handler.link, label = handler.label,			--no embargo date, ok to link to article
    			prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    	end
    	return text;
    end
    
    -- Formats a DOI and checks for DOI errors.
    
    -- DOI names contain two parts: prefix and suffix separated by a forward slash.
    --  Prefix: directory indicator '10.' followed by a registrant code
    --  Suffix: character string of any length chosen by the registrant
    
    -- This function checks a DOI name for: prefix/suffix.  If the doi name contains spaces or endashes,
    -- or, if it ends with a period or a comma, this function will emit a bad_doi error message.
    
    -- DOI names are case-insensitive and can incorporate any printable Unicode characters so the test for spaces, endash,
    -- and terminal punctuation may not be technically correct but it appears, that in practice these characters are rarely if ever used in doi names.
    
    function doi(id, inactive)
        local cat = ""
        local handler = cfg.id_handlers['DOI'];
        
        local text;
    	if is_set(inactive) then
    		local inactive_year = inactive:match("%d%d%d%d") or '';		-- try to get the year portion from the inactive date
    		text = "[[" .. handler.link .. "|" .. handler.label .. "]]:" .. id;
    		if is_set(inactive_year) then
    			table.insert( z.error_categories, "Pages with DOIs inactive since " .. inactive_year );
    		else
    			table.insert( z.error_categories, "Pages with inactive DOIs" );	-- when inactive doesn't contain a recognizable year
    		end
    		inactive = " (" .. cfg.messages['inactive'] .. " " .. inactive .. ")" 
    	else 
    		text = externallinkid({link = handler.link, label = handler.label,
    			prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    		inactive = "" 
    	end
    
    	if nil == id:match("^10%.[^%s–]-/[^%s–]-[^%.,]$") then	-- doi must begin with '10.', must contain a fwd slash, must not contain spaces or endashes, and must not end with period or comma
    		cat = ' ' .. seterror( 'bad_doi' );
    	end
    	return text .. inactive .. cat 
    end
    
    -- Formats an OpenLibrary link, and checks for associated errors.
    function openlibrary(id)
        local code = id:sub(-1,-1)
        local handler = cfg.id_handlers['OL'];
        if ( code == "A" ) then
            return externallinkid({link=handler.link, label=handler.label,
                prefix="http://openlibrary.org/authors/OL",id=id, separator=handler.separator,
                encode = handler.encode})
        elseif ( code == "M" ) then
            return externallinkid({link=handler.link, label=handler.label,
                prefix="http://openlibrary.org/books/OL",id=id, separator=handler.separator,
                encode = handler.encode})
        elseif ( code == "W" ) then
            return externallinkid({link=handler.link, label=handler.label,
                prefix= "http://openlibrary.org/works/OL",id=id, separator=handler.separator,
                encode = handler.encode})
        else
            return externallinkid({link=handler.link, label=handler.label,
                prefix= "http://openlibrary.org/OL",id=id, separator=handler.separator,
                encode = handler.encode}) .. 
                ' ' .. seterror( 'bad_ol' );
        end
    end
    
    --[[
    Validate and format an issn.  This code fixes the case where an editor has included an ISSN in the citation but has separated the two groups of four
    digits with a space.  When that condition occurred, the resulting link looked like this:
    
    	|issn=0819 4327 gives: [http://www.worldcat.org/issn/0819 4327 0819 4327]  -- can't have spaces in an external link
    	
    This code now prevents that by inserting a hyphen at the issn midpoint.  It also validates the issn for length and makes sure that the checkdigit agrees
    with the calculated value.  Incorrect length (8 digits), characters other than 0-9 and X, or checkdigit / calculated value mismatch will all cause a check issn
    error message.  The issn is always displayed with a hyphen, even if the issn was given as a single group of 8 digits.
    ]]
    function issn(id)
    	local issn_copy = id;		-- save a copy of unadulterated issn; use this version for display if issn does not validate
    	local handler = cfg.id_handlers['ISSN'];
    	local text;
    	local valid_issn = true;
    
    	id=id:gsub( "[%s-–]", "" );									-- strip spaces, hyphens, and ndashes from the issn
    
    	if 8 ~= id:len() or nil == id:match( "^%d*X?$" ) then		-- validate the issn: 8 didgits long, containing only 0-9 or X in the last position
    		valid_issn=false;										-- wrong length or improper character
    	else
    		valid_issn=is_valid_isxn(id, 8);						-- validate issn
    	end
    
    	if true == valid_issn then
    		id = string.sub( id, 1, 4 ) .. "-" .. string.sub( id, 5 );	-- if valid, display correctly formatted version
    	else
    		id = issn_copy;											-- if not valid, use the show the invalid issn with error message
    	end
    	
    	text = externallinkid({link = handler.link, label = handler.label,
    		prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
     
    	if false == valid_issn then
    		text = text .. ' ' .. seterror( 'bad_issn' )			-- add an error message if the issn is invalid
    	end 
    	
    	return text
    end
    
    --[[
    This function sets default title types (equivalent to the citation including |type=<default value>) for those citations that have defaults.
    Also handles the special case where it is desireable to omit the title type from the rendered citation (|type=none).
    ]]
    function set_titletype(cite_class, title_type)
    	if is_set(title_type) then
    		if "none" == title_type then
    			title_type = "";					-- if |type=none then type parameter not displayed
    		end
    		return title_type;						-- if |type= has been set to any other value use that value
    	end
    
    	if "AV media notes" == cite_class or "DVD notes" == cite_class then		-- if this citation is cite AV media notes or cite DVD notes
    		return "Media notes";					-- display AV media notes / DVD media notes annotation
    
    	elseif "podcast" == cite_class then			-- if this citation is cite podcast
    		return "Podcast";						-- display podcast annotation
    
    	elseif "pressrelease" == cite_class then	-- if this citation is cite press release
    		return "Press release";					-- display press release annotation
    
    	elseif "techreport" == cite_class then		-- if this citation is cite techreport
    		return "Technical report";				-- display techreport annotation
    	
    	elseif "thesis" == cite_class then			-- if this citation is cite thesis (degree option handled after this function returns)
    			return "Thesis";					-- display simple thesis annotation (without |degree= modification)
    	end
    end
    
    --[[
    Determines whether a URL string is valid
    
    At present the only check is whether the string appears to 
    be prefixed with a URI scheme.  It is not determined whether 
    the URI scheme is valid or whether the URL is otherwise well 
    formed.
    ]]
    function checkurl( url_str )
        -- Protocol-relative or URL scheme
        return url_str:sub(1,2) == "//" or url_str:match( "^[^/]*:" ) ~= nil;
    end
    
    -- Removes irrelevant text and dashes from ISBN number
    -- Similar to that used for Special:BookSources
    function cleanisbn( isbn_str )
        return isbn_str:gsub( "[^-0-9X]", "" );
    end
    
    -- Extract page numbers from external wikilinks in any of the |page=, |pages=, or |at= parameters for use in COinS.
    function get_coins_pages (pages)
    	if not is_set (pages) then return pages; end			-- if no page numbers then we're done
    	
        while true do
    		pattern = pages:match("%[([%w/:\.]+%s+)[%w%d].*%]");	-- pattern is the opening bracket, the url and following space(s): "[url "
    		if nil == pattern then break; end					-- no more urls
    		pages = pages:gsub(pattern, "");					-- remove as many instances of pattern as possible
    	end
    	pages = pages:gsub("[%[%]]", "");						-- remove the brackets
    	pages = pages:gsub("–", "-" );							-- replace endashes with hyphens
    	pages = pages:gsub("&%w+;", "-" );						-- and replace html entities (&ndash; etc) with hyphens; do we need to replace numerical entities like &#32; and the like?
    	return pages;
    end
    
    --[[
    ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in checkisbn().
    If the number is valid the result will be 0. Before calling this function, issbn/issn must be checked for length and stripped of dashes,
    spaces and other non-isxn characters.
    ]]
    function is_valid_isxn (isxn_str, len)
    	local temp = 0;
    	isxn_str = { isxn_str:byte(1, len) };	-- make a table of bytes
    	len = len+1;							-- adjust to be a loop counter
    	for i, v in ipairs( isxn_str ) do		-- loop through all of the bytes and calculate the checksum
    		if v == string.byte( "X" ) then		-- if checkdigit is X
    			temp = temp + 10*( len - i );	-- it represents 10 decimal
    		else
    			temp = temp + tonumber( string.char(v) )*(len-i);
    		end
    	end
    	return temp % 11 == 0;					-- returns true if calculation result is zero
    end
    
    -- Determines whether an ISBN string is valid
    function checkisbn( isbn_str )
    	if nil ~= isbn_str:match("[^%s-0-9X]") then return false; end		-- fail if isbn_str contains anything but digits, hyphens, or the uppercase X
    	isbn_str = isbn_str:gsub( "-", "" ):gsub( " ", "" );	-- remove hyphens and spaces
    	local len = isbn_str:len();
     
    	if len ~= 10 and len ~= 13 then
    		return false;
    	end
    
    	if len == 10 then
    		if isbn_str:match( "^%d*X?$" ) == nil then return false; end
    		return is_valid_isxn(isbn_str, 10);
    	else
    		local temp = 0;
    		if isbn_str:match( "^97[89]%d*$" ) == nil then return false; end	-- isbn13 begins with 978 or 979
    		isbn_str = { isbn_str:byte(1, len) };
    		for i, v in ipairs( isbn_str ) do
    			temp = temp + (3 - 2*(i % 2)) * tonumber( string.char(v) );
    		end
    		return temp % 10 == 0;
    	end
    end
    
    -- Gets the display text for a wikilink like [[A|B]] or [[B]] gives B
    function removewikilink( str )
        return (str:gsub( "%[%[([^%[%]]*)%]%]", function(l)
            return l:gsub( "^[^|]*|(.*)$", "%1" ):gsub("^%s*(.-)%s*$", "%1");
        end));
    end
    
    -- Escape sequences for content that will be used for URL descriptions
    function safeforurl( str )
        if str:match( "%[%[.-%]%]" ) ~= nil then 
            table.insert( z.message_tail, { seterror( 'wikilink_in_url', {}, true ) } );
        end
        
        return str:gsub( '[%[%]\n]', {    
            ['['] = '&#91;',
            [']'] = '&#93;',
            ['\n'] = ' ' } );
    end
    
    -- Converts a hyphen to a dash
    function hyphentodash( str )
        if not is_set(str) or str:match( "[%[%]{}<>]" ) ~= nil then
            return str;
        end    
        return str:gsub( '-', '–' );
    end
    
    -- Protects a string that will be wrapped in wiki italic markup '' ... ''
    function safeforitalics( str )
        --[[ Note: We can not use <i> for italics, as the expected behavior for
        italics specified by ''...'' in the title is that they will be inverted
        (i.e. unitalicized) in the resulting references.  In addition, <i> and ''
        tend to interact poorly under Mediawiki's HTML tidy. ]]
        
        if not is_set(str) then
            return str;
        else
            if str:sub(1,1) == "'" then str = "<span />" .. str; end
            if str:sub(-1,-1) == "'" then str = str .. "<span />"; end
            
            -- Remove newlines as they break italics.
            return str:gsub( '\n', ' ' );
        end
    end
    
    --[[
    Joins a sequence of strings together while checking for duplicate separation
    characters.
    ]]
    function safejoin( tbl, duplicate_char )
        --[[
        Note: we use string functions here, rather than ustring functions.
        
        This has considerably faster performance and should work correctly as 
        long as the duplicate_char is strict ASCII.  The strings
        in tbl may be ASCII or UTF8.
        ]]
        
        local str = '';
        local comp = '';
        local end_chr = '';
        local trim;
        for _, value in ipairs( tbl ) do
            if value == nil then value = ''; end
            
            if str == '' then
                str = value;
            elseif value ~= '' then
                if value:sub(1,1) == '<' then
                    -- Special case of values enclosed in spans and other markup.
                    comp = value:gsub( "%b<>", "" );
                else
                    comp = value;
                end
                
                if comp:sub(1,1) == duplicate_char then
                    trim = false;
                    end_chr = str:sub(-1,-1);
                    -- str = str .. "<HERE(enchr=" .. end_chr.. ")"
                    if end_chr == duplicate_char then
                        str = str:sub(1,-2);
                    elseif end_chr == "'" then
                        if str:sub(-3,-1) == duplicate_char .. "''" then
                            str = str:sub(1, -4) .. "''";
                        elseif str:sub(-5,-1) == duplicate_char .. "]]''" then
                            trim = true;
                        elseif str:sub(-4,-1) == duplicate_char .. "]''" then
                            trim = true;
                        end
                    elseif end_chr == "]" then
                        if str:sub(-3,-1) == duplicate_char .. "]]" then
                            trim = true;
                        elseif str:sub(-2,-1) == duplicate_char .. "]" then
                            trim = true;
                        end
                    elseif end_chr == " " then
                        if str:sub(-2,-1) == duplicate_char .. " " then
                            str = str:sub(1,-3);
                        end
                    end
    
                    if trim then
                        if value ~= comp then 
                            local dup2 = duplicate_char;
                            if dup2:match( "%A" ) then dup2 = "%" .. dup2; end
                            
                            value = value:gsub( "(%b<>)" .. dup2, "%1", 1 )
                        else
                            value = value:sub( 2, -1 );
                        end
                    end
                end
                str = str .. value;
            end
        end
        return str;
    end  
    
    -- Attempts to convert names to initials.
    function reducetoinitials(first)
        local initials = {}
        for word in string.gmatch(first, "%S+") do
            table.insert(initials, string.sub(word,1,1)) -- Vancouver format does not include full stops.
        end
        return table.concat(initials) -- Vancouver format does not include spaces.
    end
    
    -- Formats a list of people (e.g. authors / editors) 
    function listpeople(control, people)
        local sep = control.sep;
        local namesep = control.namesep
        local format = control.format
        local maximum = control.maximum
        local lastauthoramp = control.lastauthoramp;
        local text = {}
        local etal = false;
        
        if sep:sub(-1,-1) ~= " " then sep = sep .. " " end
        if maximum ~= nil and maximum < 1 then return "", 0; end
        
        for i,person in ipairs(people) do
            if is_set(person.last) then
                local mask = person.mask
                local one
                local sep_one = sep;
                if maximum ~= nil and i > maximum then
                    etal = true;
                    break;
                elseif (mask ~= nil) then
                    local n = tonumber(mask)
                    if (n ~= nil) then
                        one = string.rep("&mdash;",n)
                    else
                        one = mask;
                        sep_one = " ";
                    end
                else
                    one = person.last
                    local first = person.first
                    if is_set(first) then 
                        if ( "vanc" == format ) then first = reducetoinitials(first) end
                        one = one .. namesep .. first 
                    end
                    if is_set(person.link) then one = "[[" .. person.link .. "|" .. one .. "]]" end
                    if is_set(person.link) and nil ~= person.link:find("//") then one = one .. " " .. seterror( 'bad_authorlink' ) end	-- check for url in author link;
                end
                table.insert( text, one )
                table.insert( text, sep_one )
            end
        end
    
        local count = #text / 2;
        if count > 0 then 
            if count > 1 and is_set(lastauthoramp) and not etal then
                text[#text-2] = " & ";
            end
            text[#text] = nil; 
        end
        
        local result = table.concat(text) -- construct list
        if etal then 
            local etal_text = cfg.messages['et al'];
            result = result .. " " .. etal_text;
        end
        
        -- if necessary wrap result in <span> tag to format in Small Caps
        if ( "scap" == format ) then result = 
            '<span class="smallcaps" style="font-variant:small-caps">' .. result .. '</span>';
        end 
        return result, count
    end
    
    -- Generates a CITEREF anchor ID.
    function anchorid( options )
        return "CITEREF" .. table.concat( options );
    end
    
    -- Gets name list from the input arguments
    function extractnames(args, list_name)
        local names = {};
        local i = 1;
        local last;
        
        while true do
            last = selectone( args, cfg.aliases[list_name .. '-Last'], 'redundant_parameters', i );
            if not is_set(last) then
                -- just in case someone passed in an empty parameter
                break;
            end
            names[i] = {
                last = last,
                first = selectone( args, cfg.aliases[list_name .. '-First'], 'redundant_parameters', i ),
                link = selectone( args, cfg.aliases[list_name .. '-Link'], 'redundant_parameters', i ),
                mask = selectone( args, cfg.aliases[list_name .. '-Mask'], 'redundant_parameters', i )
            };
            i = i + 1;
        end
        return names;
    end
    
    -- Populates ID table from arguments using configuration settings
    function extractids( args )
        local id_list = {};
        for k, v in pairs( cfg.id_handlers ) do    
            v = selectone( args, v.parameters, 'redundant_parameters' );
            if is_set(v) then id_list[k] = v; end
        end
        return id_list;
    end
    
    -- Takes a table of IDs and turns it into a table of formatted ID outputs.
    function buildidlist( id_list, options )
        local new_list, handler = {};
        
        function fallback(k) return { __index = function(t,i) return cfg.id_handlers[k][i] end } end;
        
        for k, v in pairs( id_list ) do
            -- fallback to read-only cfg
            handler = setmetatable( { ['id'] = v }, fallback(k) );
            
            if handler.mode == 'external' then
                table.insert( new_list, {handler.label, externallinkid( handler ) } );
            elseif handler.mode == 'internal' then
                table.insert( new_list, {handler.label, internallinkid( handler ) } );
            elseif handler.mode ~= 'manual' then
                error( cfg.messages['unknown_ID_mode'] );
            elseif k == 'DOI' then
                table.insert( new_list, {handler.label, doi( v, options.DoiBroken ) } );
            elseif k == 'ASIN' then
                table.insert( new_list, {handler.label, amazon( v, options.ASINTLD ) } ); 
            elseif k == 'LCCN' then
                table.insert( new_list, {handler.label, lccn( v ) } );
            elseif k == 'OL' then
                table.insert( new_list, {handler.label, openlibrary( v ) } );
            elseif k == 'PMC' then
                table.insert( new_list, {handler.label, pmc( v, options.Embargo ) } );
            elseif k == 'PMID' then
                table.insert( new_list, {handler.label, pmid( v ) } );
            elseif k == 'ISSN' then
            	table.insert( new_list, {handler.label, issn( v ) } );
            elseif k == 'ISBN' then
                local ISBN = internallinkid( handler );
                if not checkisbn( v ) and not is_set(options.IgnoreISBN) then
                    ISBN = ISBN .. seterror( 'bad_isbn', {}, false, " ", "" );
                end
                table.insert( new_list, {handler.label, ISBN } );                
            else
                error( cfg.messages['unknown_manual_ID'] );
            end
        end
        
        function comp( a, b )	-- used in following table.sort()
            return a[1] < b[1];
        end
        
        table.sort( new_list, comp );
        for k, v in ipairs( new_list ) do
            new_list[k] = v[2];
        end
        
        return new_list;
    end
      
    -- Chooses one matching parameter from a list of parameters to consider
    -- Generates an error if more than one match is present.
    function selectone( args, possible, error_condition, index )
        local value = nil;
        local selected = '';
        local error_list = {};
        
        if index ~= nil then index = tostring(index); end
        
        -- Handle special case of "#" replaced by empty string
        if index == '1' then
            for _, v in ipairs( possible ) do
                v = v:gsub( "#", "" );
                if is_set(args[v]) then
                    if value ~= nil and selected ~= v then
                        table.insert( error_list, v );
                    else
                        value = args[v];
                        selected = v;
                    end
                end
            end        
        end
        
        for _, v in ipairs( possible ) do
            if index ~= nil then
                v = v:gsub( "#", index );
            end
            if is_set(args[v]) then
                if value ~= nil and selected ~=  v then
                    table.insert( error_list, v );
                else
                    value = args[v];
                    selected = v;
                end
            end
        end
        
        if #error_list > 0 then
            local error_str = "";
            for _, k in ipairs( error_list ) do
                if error_str ~= "" then error_str = error_str .. cfg.messages['parameter-separator'] end
                error_str = error_str .. wrap( 'parameter', k );
            end
            if #error_list > 1 then
                error_str = error_str .. cfg.messages['parameter-final-separator'];
            else
                error_str = error_str .. cfg.messages['parameter-pair-separator'];
            end
            error_str = error_str .. wrap( 'parameter', selected );
            table.insert( z.message_tail, { seterror( error_condition, {error_str}, true ) } );
        end
        
        return value, selected;
    end
    
    -- COinS metadata (see <http://ocoins.info/>) allows automated tools to parse
    -- the citation information.
    function COinS(data)
        if 'table' ~= type(data) or nil == next(data) then
            return '';
        end
        
        local ctx_ver = "Z39.88-2004";
        
        -- treat table strictly as an array with only set values.
        local OCinSoutput = setmetatable( {}, {
            __newindex = function(self, key, value)
                if is_set(value) then
                    rawset( self, #self+1, table.concat{ key, '=', mw.uri.encode( removewikilink( value ) ) } );
                end
            end
        });
        
        if is_set(data.Chapter) then
            OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
            OCinSoutput["rft.genre"] = "bookitem";
            OCinSoutput["rft.btitle"] = data.Chapter;
            OCinSoutput["rft.atitle"] = data.Title;
        elseif is_set(data.Periodical) then
            OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:journal";
            OCinSoutput["rft.genre"] = "article";
            OCinSoutput["rft.jtitle"] = data.Periodical;
            OCinSoutput["rft.atitle"] = data.Title;
        else
            OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
            OCinSoutput["rft.genre"] = "book"
            OCinSoutput["rft.btitle"] = data.Title;
        end
        
        OCinSoutput["rft.place"] = data.PublicationPlace;
        OCinSoutput["rft.date"] = data.Date;
        OCinSoutput["rft.series"] = data.Series;
        OCinSoutput["rft.volume"] = data.Volume;
        OCinSoutput["rft.issue"] = data.Issue;
        OCinSoutput["rft.pages"] = data.Pages;
        OCinSoutput["rft.edition"] = data.Edition;
        OCinSoutput["rft.pub"] = data.PublisherName;
        
        for k, v in pairs( data.ID_list ) do
            local id, value = cfg.id_handlers[k].COinS;
            if k == 'ISBN' then value = cleanisbn( v ); else value = v; end
            if string.sub( id or "", 1, 4 ) == 'info' then
                OCinSoutput["rft_id"] = table.concat{ id, "/", v };
            else
                OCinSoutput[ id ] = value;
            end
        end
        
        local last, first;
        for k, v in ipairs( data.Authors ) do
            last, first = v.last, v.first;
            if k == 1 then
                if is_set(last) then
                    OCinSoutput["rft.aulast"] = last;
                end
                if is_set(first) then 
                    OCinSoutput["rft.aufirst"] = first;
                end
            end
            if is_set(last) and is_set(first) then
                OCinSoutput["rft.au"] = table.concat{ last, ", ", first };
            elseif is_set(last) then
                OCinSoutput["rft.au"] = last;
            end
        end
        
        OCinSoutput.rft_id = data.URL;
        OCinSoutput.rfr_id = table.concat{ "info:sid/", mw.site.server:match( "[^/]*$" ), ":", data.RawPage };
        OCinSoutput = setmetatable( OCinSoutput, nil );
        
        -- sort with version string always first, and combine.
        table.sort( OCinSoutput );
        table.insert( OCinSoutput, 1, "ctx_ver=" .. ctx_ver );  -- such as "Z39.88-2004"
        return table.concat(OCinSoutput, "&");
    end
    
    --[[
    This is the main function doing the majority of the citation
    formatting.
    ]]
    function citation0( config, args)
        --[[ 
        Load Input Parameters
        The argment_wrapper facillitates the mapping of multiple
        aliases to single internal variable.
        ]]
        local A = argument_wrapper( args );
    
        local i 
        local PPrefix = A['PPrefix']
        local PPPrefix = A['PPPrefix']
        if is_set( A['NoPP'] ) then PPPrefix = "" PPrefix = "" end
        
        -- Pick out the relevant fields from the arguments.  Different citation templates
        -- define different field names for the same underlying things.    
        local Authors = A['Authors'];
        local a = extractnames( args, 'AuthorList' );
    
        local Coauthors = A['Coauthors'];
        local Others = A['Others'];
        local Editors = A['Editors'];
        local e = extractnames( args, 'EditorList' );
    
        local Year = A['Year'];
        local PublicationDate = A['PublicationDate'];
        local OrigYear = A['OrigYear'];
        local Date = A['Date'];
        local LayDate = A['LayDate'];
        ------------------------------------------------- Get title data
        local Title = A['Title'];
        local BookTitle = A['BookTitle'];
        local Conference = A['Conference'];
        local TransTitle = A['TransTitle'];
        local TitleNote = A['TitleNote'];
        local TitleLink = A['TitleLink'];
        local Chapter = A['Chapter'];
        local ChapterLink = A['ChapterLink'];
        local TransChapter = A['TransChapter'];
        local TitleType = A['TitleType'];
        local Degree = A['Degree'];
        local Docket = A['Docket'];
        local ArchiveURL = A['ArchiveURL'];
        local URL = A['URL']
        local URLorigin = A:ORIGIN('URL');
        local ChapterURL = A['ChapterURL'];
        local ChapterURLorigin = A:ORIGIN('ChapterURL');
        local ConferenceURL = A['ConferenceURL'];
        local ConferenceURLorigin = A:ORIGIN('ConferenceURL');
        local Periodical = A['Periodical'];
    
    	local Series = A['Series'];
        local Volume = A['Volume'];
        local Issue = A['Issue'];
        local Position = '';
        local Page = A['Page'];
        local Pages = hyphentodash( A['Pages'] );	
        local At = A['At'];
    
        local Edition = A['Edition'];
        local PublicationPlace = A['PublicationPlace']
        local Place = A['Place'];
        
        local PublisherName = A['PublisherName'];
        local RegistrationRequired = A['RegistrationRequired'];
        local SubscriptionRequired = A['SubscriptionRequired'];
        local Via = A['Via'];
        local AccessDate = A['AccessDate'];
        local ArchiveDate = A['ArchiveDate'];
        local Agency = A['Agency'];
        local DeadURL = A['DeadURL']
        local Language = A['Language'];
        local Format = A['Format'];
        local Ref = A['Ref'];
    	local DoiBroken = A['DoiBroken'];
    	local ID = A['ID'];
        local ASINTLD = A['ASINTLD'];
        local IgnoreISBN = A['IgnoreISBN'];
        local Embargo = A['Embargo'];
    
        local ID_list = extractids( args );
        
        local Quote = A['Quote'];
        local PostScript = A['PostScript'];
    
        local LayURL = A['LayURL'];
        local LaySource = A['LaySource'];
        local Transcript = A['Transcript'];
        local TranscriptURL = A['TranscriptURL'] 
        local TranscriptURLorigin = A:ORIGIN('TranscriptURL');
        local sepc = A['Separator'];
    
        local LastAuthorAmp = A['LastAuthorAmp'];
        local no_tracking_cats = A['NoTracking'];
    
    --these are used by cite interview
    	local Callsign = A['Callsign'];
    	local City = A['City'];
    	local Cointerviewers = A['Cointerviewers'];			-- deprecated
    	local Interviewer = A['Interviewer'];				-- deprecated
    	local Program = A['Program'];
    
    --local variables that are not cs1 parameters
        local page_type;									-- is this needed?  Doesn't appear to be used anywhere;
        local use_lowercase = ( sepc ~= '.' );
        local this_page = mw.title.getCurrentTitle();		--Also used for COinS and for language
    	local anchor_year;									-- used in the CITEREF identifier
    	local COinS_date;									-- used in the COinS metadata
    
    -- Set postscript default.
    	if not is_set (PostScript) then						-- if |postscript= has not been set (Postscript is nil which is the default for {{citation}}) and
    		if (config.CitationClass ~= "citation") then	-- this template is not a citation template
    			PostScript = '.';							-- must be a cite xxx template so set postscript to default (period)
    		end
    	else
    		if PostScript:lower() == 'none' then			-- if |postscript=none then
    			PostScript = '';							-- no postscript
    		end
    	end
    
    --check this page to see if it is in one of the namespaces that cs1 is not supposed to add to the error categories.
    	if not is_set(no_tracking_cats) then				-- ignore if we are already not going to categorize this page
    		for k, v in pairs( cfg.uncategorized_namespaces ) do	-- otherwise, spin through the list of namespaces we don't include in error categories
    			if this_page.nsText == v then				-- if we find one
    				no_tracking_cats = "true";				-- set no_trackin_cats
    				break;									-- and we're done
                end
            end
        end
    
    -- check for extra |page=, |pages= or |at= parameters. 
        if is_set(Page) then
            if is_set(Pages) or is_set(At) then
                Page = Page .. " " .. seterror('extra_pages');	-- add error message
                Pages = '';										-- unset the others
                At = '';
            end
        elseif is_set(Pages) then
            if is_set(At) then
                Pages = Pages .. " " .. seterror('extra_pages');	-- add error messages
                At = '';											-- unset
            end
        end    
    
    -- both |publication-place= and |place= (|location=) allowed if different
        if not is_set(PublicationPlace) and is_set(Place) then
            PublicationPlace = Place;							-- promote |place= (|location=) to |publication-place
        end
        
        if PublicationPlace == Place then Place = ''; end		-- don't need both if they are the same
        
    --[[
    Parameter remapping for cite encyclopedia:
    When the citation has these parameters:
    	|encyclopedia and |title then map |title to |article and |encyclopedia to |title
    	|encyclopedia and |article then map |encyclopedia to |title
    	|encyclopedia then map |encyclopedia to |title
    
    	|trans_title maps to |trans_chapter when |title is re-mapped
    
    All other combinations of |encyclopedia, |title, and |article are not modified
    ]]
    	if ( config.CitationClass == "encyclopaedia" ) then
    		if is_set(Periodical) then					-- Periodical is set when |encyclopedia is set
    			if is_set(Title) then
    				if not is_set(Chapter) then
    					Chapter = Title;				-- |encyclopedia and |title are set so map |title to |article and |encyclopedia to |title
    					TransChapter = TransTitle;
    					Title = Periodical;
    					Periodical = '';				-- redundant so unset
    					TransTitle = '';				-- redundant so unset
    				end
    			else									-- |title not set
    				Title = Periodical;					-- |encyclopedia set and |article set or not set so map |encyclopedia to |title
    				Periodical = '';					-- redundant so unset
    			end
    		end
    	end
    
    --special cases for citation.
    	if (config.CitationClass == "citation") then		-- for citation templates
    		if not is_set (Ref) then						-- if |ref= is not set
    			Ref = "harv";								-- set default |ref=harv
    		end
    		if not is_set (sepc) then						-- if |separator= is not set
    			sepc = ',';									-- set citation separator to its default (comma)
    		end
    	else												-- not a citation template
    		if not is_set (sepc) then						-- if |separator= has not been set
    			sepc = '.';									-- set cite xxx separator to its default (period)
    		end
    	end
    
    -- check for specital case where |separator=none
    	if 'none' == sepc:lower() then						-- if |separator=none
    		sepc = '';										-- then set it to a empty string
    	end
    
    -- Special case for cite techreport.
    	if (config.CitationClass == "techreport") then	-- special case for cite techreport
    		if is_set(Issue) then						-- cite techreport uses 'number', which other citations aliase to 'issue'
    			if not is_set(ID) then					-- can we use ID for the "number"?
    				ID = Issue;							-- yes, use it
    				Issue = "";							-- unset Issue so that "number" isn't duplicated in the rendered citation or COinS metadata
    			else									-- can't use ID so emit error message
    				ID = ID .. " " .. seterror('redundant_parameters', '<code>&#124;id=</code> and <code>&#124;number=</code>');
    			end
    		end	
    	end
    
    -- special case for cite interview
    	if (config.CitationClass == "interview") then
    		if is_set(Program) then
    			ID = ' ' .. Program;
    		end
    		if is_set(Callsign) then
    			if is_set(ID) then
    				ID = ID .. sepc .. ' ' .. Callsign;
    			else
    				ID = ' ' .. Callsign;
    			end
    		end
    		if is_set(City) then
    			if is_set(ID) then
    				ID = ID .. sepc .. ' ' .. City;
    			else
    				ID = ' ' .. City;
    			end
    		end
    
    		if is_set(Interviewer) then
    			if is_set(TitleType) then
    				Others = ' ' .. TitleType .. ' with ' .. Interviewer;
    				TitleType = '';
    			else
    				Others = ' ' .. 'Interview with ' .. Interviewer;
    			end
    			if is_set(Cointerviewers) then
    				Others = Others .. sepc .. ' ' .. Cointerviewers;
    			end
    		else
    			Others = '(Interview)';
    		end
    	end
    
    --Account for the oddity that is {{cite journal}} with |pmc= set and |url= not set
    	if config.CitationClass == "journal" and not is_set(URL) and is_set(ID_list['PMC']) then
    		if not is_embargoed(Embargo) then
    			URL=cfg.id_handlers['PMC'].prefix .. ID_list['PMC'];	-- set url to be the same as the PMC external link if not embargoed
    			URLorigin = cfg.id_handlers['PMC'].parameters[1];		-- set URLorigin to parameter name for use in error message if citation is missing a |title=
    		end
    	end
    
    -- Account for the oddity that is {{cite conference}}, before generation of COinS data.
    --TODO: if this is only for {{cite conference}}, shouldn't we be checking? (if config.CitationClass=='conference' then ...)
    	if is_set(BookTitle) then
    		Chapter = Title;
    		ChapterLink = TitleLink;
    		TransChapter = TransTitle;
    		Title = BookTitle;
    		TitleLink = '';
    		TransTitle = '';
    	end
    
    -- Account for the oddity that is {{cite episode}}, before generation of COinS data.
    --[[	-- {{cite episode}} is not currently supported by this module
    	if config.CitationClass == "episode" then
    		local AirDate = A['AirDate'];
    		local SeriesLink = A['SeriesLink'];
    		local Season = A['Season'];
    		local SeriesNumber = A['SeriesNumber'];
    		local Network = A['Network'];
    		local Station = A['Station'];
    		local s, n = {}, {};
    		local Sep = (first_set(A["SeriesSeparator"], A["Separator"]) or "") .. " ";
    		
    		if is_set(Issue) then table.insert(s, cfg.messages["episode"] .. " " .. Issue); Issue = ''; end
    		if is_set(Season) then table.insert(s, cfg.messages["season"] .. " " .. Season); end
    		if is_set(SeriesNumber) then table.insert(s, cfg.messages["series"] .. " " .. SeriesNumber); end
    		if is_set(Network) then table.insert(n, Network); end
    		if is_set(Station) then table.insert(n, Station); end
    		
    		Date = Date or AirDate;
    		Chapter = Title;
    		ChapterLink = TitleLink;
    		TransChapter = TransTitle;
    		Title = Series;
    		TitleLink = SeriesLink;
    		TransTitle = '';
    		
    		Series = table.concat(s, Sep);
    		ID = table.concat(n, Sep);
    	end
    -- end of {{cite episode}} stuff]]
    
    -- legacy: promote concatenation of |day=, |month=, and |year= to Date if Date not set; or, promote PublicationDate to Date if neither Date nor Year are set.
    	if not is_set(Date) then
    		Date = Year;						-- promote Year to Date
    		Year = nil;							-- make nil so Year as empty string isn't used for CITEREF
    		if is_set(Date) then
    			local Month = A['Month'];
    			if is_set(Month) then
    				Date = Month .. " " .. Date;
    				local Day = A['Day']
    				if is_set(Day) then Date = Day .. " " .. Date end
    			end
    		elseif is_set(PublicationDate) then	-- use PublicationDate when |date= and |year= are not set
    			Date = PublicationDate;			-- promonte PublicationDate to Date
    			PublicationDate = '';			-- unset, no longer needed
    		end
    	end
    
    	if PublicationDate == Date then PublicationDate = ''; end	-- if PublicationDate is same as Date, don't display in rendered citation
    
    
    --[[
    Go test all of the date-holding parameters for valid MOS:DATE format and make sure that dates are real dates. This must be done before we do COinS because here is where
    we get the date used in the metadata.
    
    Date validation supporting code is in Module:Citation/CS1/Date_validation
    ]]
    	anchor_year, COinS_date, error_message = dates({['accessdate']=AccessDate, ['airdate']=AirDate, ['archivedate']=ArchiveDate, ['date']=Date, ['doi_brokendate']=DoiBroken,
    		['embargo']=Embargo, ['laydate']=LayDate, ['publicationdate']=PublicationDate, ['year']=Year});
    	if is_set(error_message) then
    		table.insert( z.message_tail, { seterror( 'bad_date', {error_message}, true ) } );	-- add this error message
    	end
    
    -- At this point fields may be nil if they weren't specified in the template use.  We can use that fact.
    
        -- COinS metadata (see <http://ocoins.info/>) for
        -- automated parsing of citation information.
        local OCinSoutput = COinS{
            ['Periodical'] = Periodical,
            ['Chapter'] = Chapter,
            ['Title'] = Title,
            ['PublicationPlace'] = PublicationPlace,
            ['Date'] = first_set(COinS_date, Date),		-- COinS_date has correctly formatted date if Date is valid; any reason to keep Date here?  Should we be including invalid dates in metadata?
            ['Series'] = Series,
            ['Volume'] = Volume,
            ['Issue'] = Issue,
            ['Pages'] = get_coins_pages (first_set(Page, Pages, At)),	-- pages stripped of external links
            ['Edition'] = Edition,
            ['PublisherName'] = PublisherName,
            ['URL'] = first_set( URL, ChapterURL ),
            ['Authors'] = a,
            ['ID_list'] = ID_list,
            ['RawPage'] = this_page.prefixedText,
        };
    
        if is_set(Periodical) and not is_set(Chapter) and is_set(Title) then
            Chapter = Title;
            ChapterLink = TitleLink;
            TransChapter = TransTitle;
            Title = '';
            TitleLink = '';
            TransTitle = '';
        end
    
        -- Now perform various field substitutions.
        -- We also add leading spaces and surrounding markup and punctuation to the
        -- various parts of the citation, but only when they are non-nil.
        if not is_set(Authors) then
            local Maximum = tonumber( A['DisplayAuthors'] );
            
            -- Preserve old-style implicit et al.
            if not is_set(Maximum) and #a == 9 then 
                Maximum = 8;
                table.insert( z.message_tail, { seterror('implict_etal_author', {}, true ) } );
            elseif not is_set(Maximum) then
                Maximum = #a + 1;
            end
                
            local control = { 
                sep = A["AuthorSeparator"] .. " ",
                namesep = (first_set(A["AuthorNameSeparator"], A["NameSeparator"]) or "") .. " ",
                format = A["AuthorFormat"],
                maximum = Maximum,
                lastauthoramp = LastAuthorAmp
            };
            
            -- If the coauthor field is also used, prevent ampersand and et al. formatting.
            if is_set(Coauthors) then
                control.lastauthoramp = nil;
                control.maximum = #a + 1;
            end
            
            Authors = listpeople(control, a) 
        end
    
    	if not is_set(Authors) and is_set(Coauthors) then	-- coauthors aren't displayed if one of authors=, authorn=, or lastn= isn't specified
    		table.insert( z.message_tail, { seterror('coauthors_missing_author', {}, true) } );	-- emit error message
    	end
    
        local EditorCount
        if not is_set(Editors) then
            local Maximum = tonumber( A['DisplayEditors'] );
            -- Preserve old-style implicit et al.
            if not is_set(Maximum) and #e == 4 then 
                Maximum = 3;
                table.insert( z.message_tail, { seterror('implict_etal_editor', {}, true) } );
            elseif not is_set(Maximum) then
                Maximum = #e + 1;
            end
    
            local control = { 
                sep = A["EditorSeparator"] .. " ",
                namesep = (first_set(A["EditorNameSeparator"], A["NameSeparator"]) or "") .. " ",
                format = A['EditorFormat'],
                maximum = Maximum,
                lastauthoramp = LastAuthorAmp
            };
    
            Editors, EditorCount = listpeople(control, e);
        else
            EditorCount = 1;
        end
    
        local Cartography = "";
        local Scale = "";
        if config.CitationClass == "map" then
            if not is_set( Authors ) and is_set( PublisherName ) then
                Authors = PublisherName;
                PublisherName = "";
            end
            Cartography = A['Cartography'];
            if is_set( Cartography ) then
                Cartography = sepc .. " " .. wrap( 'cartography', Cartography, use_lowercase );
            end        
            Scale = A['Scale'];
            if is_set( Scale ) then
                Scale = sepc .. " " .. Scale;
            end        
        end
        
        if  not is_set(URL) and
            not is_set(ChapterURL) and
            not is_set(ArchiveURL) and
            not is_set(ConferenceURL) and
            not is_set(TranscriptURL) then
            
            -- Test if cite web or cite podcast |url= is missing or empty 
    		if inArray(config.CitationClass, {"web","podcast"}) then	
    			table.insert( z.message_tail, { seterror( 'cite_web_url', {}, true ) } );
    		end
            
            -- Test if accessdate is given without giving a URL
            if is_set(AccessDate) then
                table.insert( z.message_tail, { seterror( 'accessdate_missing_url', {}, true ) } );
                AccessDate = '';
            end
            
            -- Test if format is given without giving a URL
            if is_set(Format) then
                Format = Format .. seterror( 'format_missing_url' );
            end
        end
        
        -- Test if citation has no title
        if  not is_set(Chapter) and
            not is_set(Title) and
            not is_set(Periodical) and
            not is_set(Conference) and
            not is_set(TransTitle) and
            not is_set(TransChapter) then
            table.insert( z.message_tail, { seterror( 'citation_missing_title', {}, true ) } );
        end
        
        Format = is_set(Format) and " (" .. Format .. ")" or "";
        
        local OriginalURL = URL
        DeadURL = DeadURL:lower();
        if is_set( ArchiveURL ) then
            if ( DeadURL ~= "no" ) then
                URL = ArchiveURL
                URLorigin = A:ORIGIN('ArchiveURL')
            end
        end
        
        -- Format chapter / article title
        if is_set(Chapter) and is_set(ChapterLink) then 
            Chapter = "[[" .. ChapterLink .. "|" .. Chapter .. "]]";
        end
        if is_set(Periodical) and is_set(Title) then
            Chapter = wrap( 'italic-title', Chapter );
            TransChapter = wrap( 'trans-italic-title', TransChapter );
        else
    		Chapter = kern_quotes (Chapter);				-- if necessary, separate chapter title's leading and trailing quote marks from Module provided quote marks
            Chapter = wrap( 'quoted-title', Chapter );
            TransChapter = wrap( 'trans-quoted-title', TransChapter );
        end
        
        local TransError = ""
        if is_set(TransChapter) then
            if not is_set(Chapter) then
                TransError = " " .. seterror( 'trans_missing_chapter' );
            else
                TransChapter = " " .. TransChapter;
            end
        end
        
        Chapter = Chapter .. TransChapter;
        
        if is_set(Chapter) then
            if not is_set(ChapterLink) then
                if is_set(ChapterURL) then
                    Chapter = externallink( ChapterURL, Chapter ) .. TransError;
                    if not is_set(URL) then
                        Chapter = Chapter .. Format;
                        Format = "";
                    end
                elseif is_set(URL) then 
                    Chapter = externallink( URL, Chapter ) .. TransError .. Format;
                    URL = "";
                    Format = "";
                else
                    Chapter = Chapter .. TransError;
                end            
            elseif is_set(ChapterURL) then
                Chapter = Chapter .. " " .. externallink( ChapterURL, nil, ChapterURLorigin ) .. 
                    TransError;
            else
                Chapter = Chapter .. TransError;
            end
            Chapter = Chapter .. sepc .. " " -- with end-space
        elseif is_set(ChapterURL) then
            Chapter = " " .. externallink( ChapterURL, nil, ChapterURLorigin ) .. sepc .. " ";
        end        
        
        -- Format main title.
        if is_set(TitleLink) and is_set(Title) then
            Title = "[[" .. TitleLink .. "|" .. Title .. "]]"
        end
        
        if is_set(Periodical) then
    		Title = kern_quotes (Title);				-- if necessary, separate title's leading and trailing quote marks from Module provided quote marks
            Title = wrap( 'quoted-title', Title );
            TransTitle = wrap( 'trans-quoted-title', TransTitle );
        elseif inArray(config.CitationClass, {"web","news","pressrelease","conference","podcast"}) and
                not is_set(Chapter) then
    		Title = kern_quotes (Title);				-- if necessary, separate title's leading and trailing quote marks from Module provided quote marks
            Title = wrap( 'quoted-title', Title );
            TransTitle = wrap( 'trans-quoted-title', TransTitle );
        else
            Title = wrap( 'italic-title', Title );
            TransTitle = wrap( 'trans-italic-title', TransTitle );
        end
        
        TransError = "";
        if is_set(TransTitle) then
            if not is_set(Title) then
                TransError = " " .. seterror( 'trans_missing_title' );
            else
                TransTitle = " " .. TransTitle;
            end
        end
        
        Title = Title .. TransTitle;
        
        if is_set(Title) then
            if not is_set(TitleLink) and is_set(URL) then 
                Title = externallink( URL, Title ) .. TransError .. Format       
                URL = "";
                Format = "";
            else
                Title = Title .. TransError;
            end
        end
        
        if is_set(Place) then
            Place = " " .. wrap( 'written', Place, use_lowercase ) .. sepc .. " ";
        end
        
        if is_set(Conference) then
            if is_set(ConferenceURL) then
                Conference = externallink( ConferenceURL, Conference );
            end
            Conference = sepc .. " " .. Conference
        elseif is_set(ConferenceURL) then
            Conference = sepc .. " " .. externallink( ConferenceURL, nil, ConferenceURLorigin );
        end
        
        if not is_set(Position) then
            local Minutes = A['Minutes'];
            if is_set(Minutes) then
                Position = " " .. Minutes .. " " .. cfg.messages['minutes'];
            else
                local Time = A['Time'];
                if is_set(Time) then
                    local TimeCaption = A['TimeCaption']
                    if not is_set(TimeCaption) then
                        TimeCaption = cfg.messages['event'];
                        if sepc ~= '.' then
                            TimeCaption = TimeCaption:lower();
                        end
                    end
                    Position = " " .. TimeCaption .. " " .. Time;
                end
            end
        else
            Position = " " .. Position;
            At = '';
        end
        
        if not is_set(Page) then
            if is_set(Pages) then
                if is_set(Periodical) and
                    not inArray(config.CitationClass, {"encyclopaedia","web","book","news","podcast"}) then
                    Pages = ": " .. Pages;
                elseif tonumber(Pages) ~= nil then
                    Pages = sepc .." " .. PPrefix .. Pages;
                else
                    Pages = sepc .." " .. PPPrefix .. Pages;
                end
            end
        else
            if is_set(Periodical) and
                not inArray(config.CitationClass, {"encyclopaedia","web","book","news","podcast"}) then
                Page = ": " .. Page;
            else
                Page = sepc .." " .. PPrefix .. Page;
            end
        end
        
        At = is_set(At) and (sepc .. " " .. At) or "";
        Position = is_set(Position) and (sepc .. " " .. Position) or "";
        if config.CitationClass == 'map' then
            local Section = A['Section'];
            local Inset = A['Inset'];
            if first_set( Pages, Page, At ) ~= nil or sepc ~= '.' then
                if is_set( Section ) then
                    Section = ", " .. wrap( 'section', Section, true );
                end
                if is_set( Inset ) then
                    Inset = ", " .. wrap( 'inset', Inset, true );
                end
            else
                if is_set( Section ) then
                    Section = sepc .. " " .. wrap( 'section', Section, use_lowercase );
                    if is_set( Inset ) then
                        Inset = ", " .. wrap( 'inset', Inset, true );
                    end
                elseif is_set( Inset ) then
                    Inset = sepc .. " " .. wrap( 'inset', Inset, use_lowercase );
                end            
            end            
            At = At .. Section .. Inset;        
        end    
    
    	--[[Look in the list of iso639-1 language codes to see if the value provided in the language parameter matches one of them.  If a match is found, 
    	use that value; if not, then use the value that was provided with the language parameter.
    	
    	Categories are assigned in a manner similar to the {{xx icon}} templates - categorizes only mainspace citations and only when the language code is not 'en' (English).
    	]]
    	if is_set (Language) then
    --		local name = mw.language.fetchLanguageName( Language:lower(), "en" );	-- experiment: this seems to return correct ISO 639-1 language names
    		local name = cfg.iso639_1[Language:lower()];		-- get the language name if Language parameter has a valid iso 639-1 code
    		if nil == name then
    			Language=" " .. wrap( 'language', Language );	-- no match, use parameter's value
    		else
    			if 0 == this_page.namespace and 'en' ~= Language:lower() then	--found a match; is this page main / article space and English not the language?
    				Language=" " .. wrap( 'language', name .. '[[Category:Articles with ' .. name .. '-language external links]]' );	-- in main space and not English: categorize
    			else
    				Language=" " .. wrap( 'language', name );	--not in mainspace or language is English so don't categorize
    			end
    		end
    	else
    		Language="";	-- language not specified so make sure this is an empty string;
    	end
    
    	Others = is_set(Others) and (sepc .. " " .. Others) or "";
    
    -- handle type parameter for those CS1 citations that have default values
    
    	if inArray(config.CitationClass, {"AV media notes", "DVD notes", "podcast", "pressrelease", "techreport", "thesis"}) then
    		TitleType = set_titletype (config.CitationClass, TitleType);
    		if is_set(Degree) and "Thesis" == TitleType then	-- special case for cite thesis
    			TitleType = Degree .. " thesis";
    		end
    	end
    
    	if is_set(TitleType) then					-- if type parameter is specified
    		TitleType = " (" .. TitleType .. ")";	-- display it in parentheses
    	end
    
    	TitleNote = is_set(TitleNote) and (sepc .. " " .. TitleNote) or "";
        Edition = is_set(Edition) and (" " .. wrap( 'edition', Edition )) or "";
        Issue = is_set(Issue) and (" (" .. Issue .. ")") or "";
        Series = is_set(Series) and (sepc .. " " .. Series) or "";
        OrigYear = is_set(OrigYear) and (" [" .. OrigYear .. "]") or "";
        Agency = is_set(Agency) and (sepc .. " " .. Agency) or "";
    
        if is_set(Volume) then
            if ( mw.ustring.len(Volume) > 4 )
              then Volume = sepc .." " .. Volume;
              else Volume = " <b>" .. hyphentodash(Volume) .. "</b>";
            end
        end
    
    --[[ This code commented out while discussion continues until after week of 2014-03-23 live module update;
        if is_set(Volume) then
            if ( mw.ustring.len(Volume) > 4 )
              then Volume = sepc .. " " .. Volume;
              else
                  Volume = " <b>" .. hyphentodash(Volume) .. "</b>";
                  if is_set(Series) then Volume = sepc .. Volume;
                  end
            end
        end
    ]]    
        ------------------------------------ totally unrelated data
        --[[ Loosely mimic {{subscription required}} template; Via parameter identifies a delivery source that is not the publisher; these sources often, but not always, exist
        behind a registration or paywall.  So here, we've chosen to decouple via from subscription (via has never been part of the registration required template).
        
        Subscription implies paywall; Registration does not.  If both are used in a citation, the subscription required link note is displayed. There are no error messages for this condition.
        ]]
        if is_set(Via) then
            Via = " " .. wrap( 'via', Via );
        end
    
    	if is_set(SubscriptionRequired) then
            SubscriptionRequired = sepc .. " " .. cfg.messages['subscription']; --here when 'via' parameter not used but 'subscription' is
        elseif is_set(RegistrationRequired) then
            SubscriptionRequired = sepc .. " " .. cfg.messages['registration']; --here when 'via' and 'subscription' parameters not used but 'registration' is
        end
    
        if is_set(AccessDate) then
            local retrv_text = " " .. cfg.messages['retrieved']
            if (sepc ~= ".") then retrv_text = retrv_text:lower() end
            AccessDate = '<span class="reference-accessdate">' .. sepc
                .. substitute( retrv_text, {AccessDate} ) .. '</span>'
        end
        
        if is_set(ID) then ID = sepc .." ".. ID; end
       	if "thesis" == config.CitationClass and is_set(Docket) then
    		ID = sepc .." Docket ".. Docket .. ID;
    	end
    
        
        ID_list = buildidlist( ID_list, {DoiBroken = DoiBroken, ASINTLD = ASINTLD, IgnoreISBN = IgnoreISBN, Embargo=Embargo} );
    
        if is_set(URL) then
            URL = " " .. externallink( URL, nil, URLorigin );
        end
    
        if is_set(Quote) then
            if Quote:sub(1,1) == '"' and Quote:sub(-1,-1) == '"' then
                Quote = Quote:sub(2,-2);
            end
            Quote = sepc .." " .. wrap( 'quoted-text', Quote ); 
            PostScript = "";							-- CS1 does not supply terminal punctuation when |quote= is set
        end
        
        local Archived
        if is_set(ArchiveURL) then
            if not is_set(ArchiveDate) then
                ArchiveDate = seterror('archive_missing_date');
            end
            if "no" == DeadURL then
                local arch_text = cfg.messages['archived'];
                if sepc ~= "." then arch_text = arch_text:lower() end
                Archived = sepc .. " " .. substitute( cfg.messages['archived-not-dead'],
                    { externallink( ArchiveURL, arch_text ), ArchiveDate } );
                if not is_set(OriginalURL) then
                    Archived = Archived .. " " .. seterror('archive_missing_url');                               
                end
            elseif is_set(OriginalURL) then
                local arch_text = cfg.messages['archived-dead'];
                if sepc ~= "." then arch_text = arch_text:lower() end
                Archived = sepc .. " " .. substitute( arch_text,
                    { externallink( OriginalURL, cfg.messages['original'] ), ArchiveDate } );
            else
                local arch_text = cfg.messages['archived-missing'];
                if sepc ~= "." then arch_text = arch_text:lower() end
                Archived = sepc .. " " .. substitute( arch_text, 
                    { seterror('archive_missing_url'), ArchiveDate } );
            end
        else
            Archived = ""
        end
        
        local Lay
        if is_set(LayURL) then
            if is_set(LayDate) then LayDate = " (" .. LayDate .. ")" end
            if is_set(LaySource) then 
                LaySource = " &ndash; ''" .. safeforitalics(LaySource) .. "''";
            else
                LaySource = "";
            end
            if sepc == '.' then
                Lay = sepc .. " " .. externallink( LayURL, cfg.messages['lay summary'] ) .. LaySource .. LayDate
            else
                Lay = sepc .. " " .. externallink( LayURL, cfg.messages['lay summary']:lower() ) .. LaySource .. LayDate
            end            
        else
            Lay = "";
        end
        
        if is_set(Transcript) then
            if is_set(TranscriptURL) then Transcript = externallink( TranscriptURL, Transcript ); end
        elseif is_set(TranscriptURL) then
            Transcript = externallink( TranscriptURL, nil, TranscriptURLorigin );
        end
        
        local Publisher;
        if is_set(Periodical) and
            not inArray(config.CitationClass, {"encyclopaedia","web","pressrelease","podcast"}) then
            if is_set(PublisherName) then
                if is_set(PublicationPlace) then
                    Publisher = PublicationPlace .. ": " .. PublisherName;
                else
                    Publisher = PublisherName;  
                end
            elseif is_set(PublicationPlace) then
                Publisher= PublicationPlace;
            else 
                Publisher = "";
            end
            if is_set(PublicationDate) then
                if is_set(Publisher) then
                    Publisher = Publisher .. ", " .. wrap( 'published', PublicationDate );
                else
                    Publisher = PublicationDate;
                end
            end
            if is_set(Publisher) then
                Publisher = " (" .. Publisher .. ")";
            end
        else
            if is_set(PublicationDate) then
                PublicationDate = " (" .. wrap( 'published', PublicationDate ) .. ")";
            end
            if is_set(PublisherName) then
                if is_set(PublicationPlace) then
                    Publisher = sepc .. " " .. PublicationPlace .. ": " .. PublisherName .. PublicationDate;
                else
                    Publisher = sepc .. " " .. PublisherName .. PublicationDate;  
                end            
            elseif is_set(PublicationPlace) then 
                Publisher= sepc .. " " .. PublicationPlace .. PublicationDate;
            else 
                Publisher = PublicationDate;
            end
        end
        
        -- Several of the above rely upon detecting this as nil, so do it last.
        if is_set(Periodical) then
            if is_set(Title) or is_set(TitleNote) then 
                Periodical = sepc .. " " .. wrap( 'italic-title', Periodical ) 
            else 
                Periodical = wrap( 'italic-title', Periodical )
            end
        end
    
    --[[
    Handle the oddity that is cite speech.  This code overrides whatever may be the value assigned to TitleNote (through |department=) and forces it to be " (Speech)" so that
    the annotation directly follows the |title= parameter value in the citation rather than the |event= parameter value (if provided).
    ]]
    	if "speech" == config.CitationClass then				-- cite speech only
    		TitleNote = " (Speech)";							-- annotate the citation
    		if is_set (Periodical) then							-- if Periodical, perhaps because of an included |website= or |journal= parameter 
    			if is_set (Conference) then						-- and if |event= is set
    				Conference = Conference .. sepc .. " ";		-- then add appropriate punctuation to the end of the Conference variable before rendering
    			end
    		end
    	end
    
        -- Piece all bits together at last.  Here, all should be non-nil.
        -- We build things this way because it is more efficient in LUA
        -- not to keep reassigning to the same string variable over and over.
    
        local tcommon
        if inArray(config.CitationClass, {"journal","citation"}) and is_set(Periodical) then
            if is_set(Others) then Others = Others .. sepc .. " " end
            tcommon = safejoin( {Others, Title, TitleNote, Conference, Periodical, Format, TitleType, Scale, Series, 
                Language, Cartography, Edition, Publisher, Agency, Volume, Issue}, sepc );
        else 
            tcommon = safejoin( {Title, TitleNote, Conference, Periodical, Format, TitleType, Scale, Series, Language, 
                Volume, Issue, Others, Cartography, Edition, Publisher, Agency}, sepc );
        end
        
        if #ID_list > 0 then
            ID_list = safejoin( { sepc .. " ",  table.concat( ID_list, sepc .. " " ), ID }, sepc );
        else
            ID_list = ID;
        end
        
        local idcommon = safejoin( { ID_list, URL, Archived, AccessDate, Via, SubscriptionRequired, Lay, Quote }, sepc );
        local text;
        local pgtext = Position .. Page .. Pages .. At;
        
        if is_set(Authors) then
            if is_set(Coauthors) then
                Authors = Authors .. A['AuthorSeparator'] .. " " .. Coauthors
            end
            if is_set(Date) then
                Date = " ("..Date..")" .. OrigYear .. sepc .. " "
            elseif string.sub(Authors,-1,-1) == sepc then
                Authors = Authors .. " "
            else
                Authors = Authors .. sepc .. " "
            end
            if is_set(Editors) then
                local in_text = " ";
                local post_text = "";
                if is_set(Chapter) then
                    in_text = in_text .. cfg.messages['in'] .. " "
                else
                    if EditorCount <= 1 then
                        post_text = ", " .. cfg.messages['editor'];
                    else
                        post_text = ", " .. cfg.messages['editors'];
                    end
                end 
                if (sepc ~= '.') then in_text = in_text:lower() end
                Editors = in_text .. Editors .. post_text;
                if (string.sub(Editors,-1,-1) == sepc)
                    then Editors = Editors .. " "
                    else Editors = Editors .. sepc .. " "
                end
            end
            text = safejoin( {Authors, Date, Chapter, Place, Editors, tcommon }, sepc );
            text = safejoin( {text, pgtext, idcommon}, sepc );
        elseif is_set(Editors) then
            if is_set(Date) then
                if EditorCount <= 1 then
                    Editors = Editors .. ", " .. cfg.messages['editor'];
                else
                    Editors = Editors .. ", " .. cfg.messages['editors'];
                end
                Date = " (" .. Date ..")" .. OrigYear .. sepc .. " "
            else
                if EditorCount <= 1 then
                    Editors = Editors .. " (" .. cfg.messages['editor'] .. ")" .. sepc .. " "
                else
                    Editors = Editors .. " (" .. cfg.messages['editors'] .. ")" .. sepc .. " "
                end
            end
            text = safejoin( {Editors, Date, Chapter, Place, tcommon}, sepc );
            text = safejoin( {text, pgtext, idcommon}, sepc );
        else
            if is_set(Date) then
                if ( string.sub(tcommon,-1,-1) ~= sepc )
                  then Date = sepc .." " .. Date .. OrigYear
                  else Date = " " .. Date .. OrigYear
                end
            end
            if config.CitationClass=="journal" and is_set(Periodical) then
                text = safejoin( {Chapter, Place, tcommon}, sepc );
                text = safejoin( {text, pgtext, Date, idcommon}, sepc );
            else
                text = safejoin( {Chapter, Place, tcommon, Date}, sepc );
                text = safejoin( {text, pgtext, idcommon}, sepc );
            end
        end
        
    	if is_set(PostScript) and PostScript ~= sepc then
    		text = safejoin( {text, sepc}, sepc );  --Deals with italics, spaces, etc.
    		text = text:sub(1,-sepc:len()-1);
    --		text = text:sub(1,-2);	--Remove final separator (assumes that sepc is only one character)
    	end    
        
        text = safejoin( {text, PostScript}, sepc );
    
        -- Now enclose the whole thing in a <span/> element
        local options = {};
        
        if is_set(config.CitationClass) and config.CitationClass ~= "citation" then
            options.class = "citation " .. config.CitationClass;
        else
            options.class = "citation";
        end
        
        if is_set(Ref) and Ref:lower() ~= "none" then
            local id = Ref
            if ( "harv" == Ref ) then
                local names = {} --table of last names & year
                if #a > 0 then
                    for i,v in ipairs(a) do 
                        names[i] = v.last 
                        if i == 4 then break end
                    end
                elseif #e > 0 then
                    for i,v in ipairs(e) do 
                        names[i] = v.last 
                        if i == 4 then break end                
                    end
                end
    			names[ #names + 1 ] = first_set(Year, anchor_year);	-- Year first for legacy citations
                id = anchorid(names)
            end
            options.id = id;
        end
        
        if string.len(text:gsub("<span[^>/]*>.-</span>", ""):gsub("%b<>","")) <= 2 then
            z.error_categories = {};
            text = seterror('empty_citation');
            z.message_tail = {};
        end
        
        if is_set(options.id) then 
            text = '<span id="' .. mw.uri.anchorEncode(options.id) ..'" class="' .. mw.text.nowiki(options.class) .. '">' .. text .. "</span>";
        else
            text = '<span class="' .. mw.text.nowiki(options.class) .. '">' .. text .. "</span>";
        end        
    
        local empty_span = '<span style="display:none;">&nbsp;</span>';
        
        -- Note: Using display: none on then COinS span breaks some clients.
        local OCinS = '<span title="' .. OCinSoutput .. '" class="Z3988">' .. empty_span .. '</span>';
        text = text .. OCinS;
        
        if #z.message_tail ~= 0 then
            text = text .. " ";
            for i,v in ipairs( z.message_tail ) do
                if is_set(v[1]) then
                    if i == #z.message_tail then
                        text = text .. errorcomment( v[1], v[2] );
                    else
                        text = text .. errorcomment( v[1] .. "; ", v[2] );
                    end
                end
            end
        end
        
        no_tracking_cats = no_tracking_cats:lower();
        if inArray(no_tracking_cats, {"", "no", "false", "n"}) then
            for _, v in ipairs( z.error_categories ) do
                text = text .. '[[Category:' .. v ..']]';
            end
        end
        
        return text
    end
    
    -- This is used by templates such as {{cite book}} to create the actual citation text.
    function z.citation(frame)
        local pframe = frame:getParent()
        
        if nil ~= string.find( frame:getTitle(), 'sandbox', 1, true ) then				-- did the {{#invoke:}} use sandbox version?
        	cfg = mw.loadData( 'Module:Citation/CS1/Configuration/sandbox' );	-- load sandbox versions of Configuration and Whitelist and ...
        	whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist/sandbox' );
        	dates = require('Module:Citation/CS1/Date_validation/sandbox').dates	-- ... sandbox version of date validation code
        else																	-- otherwise
        	cfg = mw.loadData( 'Module:Citation/CS1/Configuration' );			-- load live versions of Configuration and Whitelist and ...
        	whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist' );
        	dates = require('Module:Citation/CS1/Date_validation').dates		-- ... live version of date validation code
    	end
    	
        local args = {};
        local suggestions = {};
        local error_text, error_state;
    
        local config = {};
        for k, v in pairs( frame.args ) do
            config[k] = v;
            args[k] = v;       
        end    
    
        for k, v in pairs( pframe.args ) do
            if v ~= '' then
                if not validate( k ) then            
                    error_text = "";
                    if type( k ) ~= 'string' then
                        -- Exclude empty numbered parameters
                        if v:match("%S+") ~= nil then
                            error_text, error_state = seterror( 'text_ignored', {v}, true );
                        end
                    elseif validate( k:lower() ) then 
                        error_text, error_state = seterror( 'parameter_ignored_suggest', {k, k:lower()}, true );
                    else
                        if #suggestions == 0 then
                            suggestions = mw.loadData( 'Module:Citation/CS1/Suggestions' );
                        end
                        if suggestions[ k:lower() ] ~= nil then
                            error_text, error_state = seterror( 'parameter_ignored_suggest', {k, suggestions[ k:lower() ]}, true );
                        else
                            error_text, error_state = seterror( 'parameter_ignored', {k}, true );
                        end
                    end                  
                    if error_text ~= '' then
                        table.insert( z.message_tail, {error_text, error_state} );
                    end                
                end
                args[k] = v;
            elseif args[k] ~= nil or (k == 'postscript') then
                args[k] = v;
            end        
        end    
        
        return citation0( config, args)
    end
    
    return z