Module:Citation/CS1: Difference between revisions

    From Nonbinary Wiki
    m>Gadget850
    (registration required)
    m>Gadget850
    (Fix via/subscription bug)
    Line 1,303: Line 1,303:
         if is_set(Via) then
         if is_set(Via) then
             Via = " " .. wrap( 'via', Via );
             Via = " " .. wrap( 'via', Via );
        end
    --      SubscriptionRequired = sepc .. " " .. cfg.messages['subscription'];  --citation always requires subscription if 'via' parameter is used
    --      SubscriptionRequired = sepc .. " " .. cfg.messages['subscription'];  --citation always requires subscription if 'via' parameter is used
                                                                                   -- This line removed because of editors desire to use via for citations that do not require subscriptions
                                                                                   -- This line removed because of editors desire to use via for citations that do not require subscriptions
         elseif is_set(SubscriptionRequired) then
         if is_set(SubscriptionRequired) then
             SubscriptionRequired = sepc .. " " .. cfg.messages['subscription_no_via']; --here when 'via' parameter not used but 'subscription' is
             SubscriptionRequired = sepc .. " " .. cfg.messages['subscription_no_via']; --here when 'via' parameter not used but 'subscription' is
         elseif is_set(RegistrationRequired) then
         elseif is_set(RegistrationRequired) then

    Revision as of 17:37, 1 September 2013

    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' );
    
    -- Contains a list of all recognized parameters
    local whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist' );
    
    -- 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
    
    -- 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;
    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
    
    -- Checks that parameter name is valid using the whitelist
    function validate( name )
        name = tostring( name );
        
        -- Normal arguments
        if whitelist.basic_arguments[ name ] then
            return true;
        end
        
        -- Arguments with numbers in them
        name = name:gsub( "%d+", "#" );
        if whitelist.numbered_arguments[ name ] then
            return true;
        end
        
        -- Not found, argument not supported.
        return false
    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 " ",
            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 " ",
            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
    
    -- Formats a DOI and checks for DOI errors.
    function doi(id, inactive)
        local cat = ""
        local handler = cfg.id_handlers['DOI'];
        
        local text;
        if is_set(inactive) then
            text = "[[" .. handler.link .. "|" .. handler.label .. "]]:" .. id;
            table.insert( z.error_categories, "Pages with DOIs inactive since " .. selectyear(inactive) );        
            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 ( string.sub(id,1,3) ~= "10." ) then      
            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
    
    --[[
    Determines whether an 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
    
    -- Determines whether an ISBN string is valid
    function checkisbn( isbn_str )
        isbn_str = cleanisbn( isbn_str ):gsub( "-", "" );
        local len = isbn_str:len();
     
        if len ~= 10 and len ~= 13 then
            return false;
        end
     
        local temp = 0;
        if len == 10 then
            if isbn_str:match( "^%d*X?$" ) == nil then return false; end
            isbn_str = { isbn_str:byte(1, len) };
            for i, v in ipairs( isbn_str ) do
                if v == string.byte( "X" ) then
                    temp = temp + 10*( 11 - i );
                else
                    temp = temp + tonumber( string.char(v) )*(11-i);
                end
            end
            return temp % 11 == 0;
        else
            if isbn_str:match( "^%d*$" ) == nil then return false; end
            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]', {    
            ['['] = '[',
            [']'] = ']',
            ['\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  
    
    --[[
    Return the year portion of a date string, if possible.  
    Returns empty string if the argument can not be interpreted
    as a year.
    ]]
    function selectyear( str )
        -- Is the input a simple number?
        local num = tonumber( str ); 
        if num ~= nil and num > 0 and num < 2100 and num == math.floor(num) then
            return str;
        else
            -- Use formatDate to interpret more complicated formats
            local lang = mw.getContentLanguage();
            local good, result;
            good, result = pcall( lang.formatDate, lang, 'Y', str )
            if good then 
                return result;
            else
                -- Can't make sense of this input, return blank.
                return "";
            end
        end
    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
                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 == 'OL' then
                table.insert( new_list, {handler.label, openlibrary( 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 )
            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 foing 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 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'];
        
        if ( config.CitationClass == "encyclopaedia" ) then
            if not is_set(Chapter) then
                if not is_set(Title) then
                    Title = Periodical;
                    Periodical = '';
                else
                    Chapter = Title
                    TransChapter = TransTitle
                    Title = '';
                    TransTitle = '';
                end
            end
        end
    
        local Series = A['Series'];
        local Volume = A['Volume'];
        local Issue = A['Issue'];
        local Position = '';
        local Page, Pages, At, page_type;
        
        Page = A['Page'];
        Pages = hyphentodash( A['Pages'] );
        At = A['At'];
        
        if is_set(Page) then
            if is_set(Pages) or is_set(At) then
                Page = Page .. " " .. seterror('extra_pages');
                Pages = '';
                At = '';
            end
        elseif is_set(Pages) then
            if is_set(At) then
                Pages = Pages .. " " .. seterror('extra_pages');
                At = '';
            end
        end    
        
        local Edition = A['Edition'];
        local PublicationPlace = A['PublicationPlace']
        local Place = A['Place'];
        
        if not is_set(PublicationPlace) and is_set(Place) then
            PublicationPlace = Place;
        end
        
        if PublicationPlace == Place then Place = ''; end
        
        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 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'];
    
        local use_lowercase = ( sepc ~= '.' );
        local this_page = mw.title.getCurrentTitle();  --Also used for COinS
        
        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
    
        if ( config.CitationClass == "journal" ) then
            if not is_set(URL) and is_set(ID_list['PMC']) then
                local Embargo = A['Embargo'];
                if is_set(Embargo) then
                    local lang = mw.getContentLanguage();
                    local good1, result1, good2, result2;
                    good1, result1 = pcall( lang.formatDate, lang, 'U', Embargo );
                    good2, result2 = pcall( lang.formatDate, lang, 'U' );
                    
                    if good1 and good2 and tonumber( result1 ) < tonumber( result2 ) then 
                        URL = "http://www.ncbi.nlm.nih.gov/pmc/articles/PMC" .. ID_list['PMC'];
                        URLorigin = cfg.id_handlers['PMC'].parameters[1];
                    end
                else
                    URL = "http://www.ncbi.nlm.nih.gov/pmc/articles/PMC" .. ID_list['PMC'];
                    URLorigin = cfg.id_handlers['PMC'].parameters[1];
                end
            end
        end
    
        -- 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 conference}}, before generation of COinS data.
        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.
        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
        
        -- 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(Date, Year, PublicationDate),
            ['Series'] = Series,
            ['Volume'] = Volume,
            ['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.
            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
    
        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(Date) then
            Date = Year;
            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
            end
        end
        
        if inArray(PublicationDate, {Date, Year}) then PublicationDate = ''; end
        if not is_set(Date) and is_set(PublicationDate) then
            Date = PublicationDate;
            PublicationDate = '';
        end
    
        -- Captures the value for Date prior to adding parens or other textual transformations
        local DateIn = Date;
        
        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 is called without giving a URL
            if ( config.CitationClass == "web" ) 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 = 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 = wrap( 'quoted-title', Title );
            TransTitle = wrap( 'trans-quoted-title', TransTitle );
        elseif inArray(config.CitationClass, {"web","news","pressrelease","conference"}) and
                not is_set(Chapter) then
            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"}) 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"}) 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    
        
        Others = is_set(Others) and (sepc .. " " .. Others) or "";
        TitleType = is_set(TitleType) and (" (" .. TitleType .. ")") or "";
        TitleNote = is_set(TitleNote) and (sepc .. " " .. TitleNote) or "";
        Language = is_set(Language) and (" " .. wrap( 'language', Language )) 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
        
        ------------------------------------ totally unrelated data
        -- Mimic {{subscription required}} template; 
        if is_set(Via) then
            Via = " " .. wrap( 'via', Via );
        end
    --      SubscriptionRequired = sepc .. " " .. cfg.messages['subscription'];   --citation always requires subscription if 'via' parameter is used
                                                                                  -- This line removed because of editors desire to use via for citations that do not require subscriptions
        if is_set(SubscriptionRequired) then
            SubscriptionRequired = sepc .. " " .. cfg.messages['subscription_no_via']; --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
        
        ID_list = buildidlist( ID_list, {DoiBroken = DoiBroken, ASINTLD = ASINTLD, IgnoreISBN = IgnoreISBN} );
    
        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
                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"}) 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
    
        -- 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,-2); --Remove final seperator    
        end    
        
        text = safejoin( {text, PostScript}, sepc );
    
        -- Now enclose the whole thing in a <span/> element
        if not is_set(Year) then
            if is_set(DateIn) then
                Year = selectyear( DateIn );
            elseif is_set(PublicationDate) then
                Year = selectyear( PublicationDate );
            end
        end
        
        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 ] = Year;
                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()
        
        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