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Module:Age: Difference between revisions

3,898 bytes added ,  11 years ago
add support for {{Age in days}} and {{Gregorian serial date}}
(implement age in years and months; could readily extend for other similar functions)
 
(add support for {{Age in days}} and {{Gregorian serial date}})
Line 1: Line 1:
-- Code to implement {{age in years and months}}.
--[[ Code for some date functions, including implementations of:
-- This could be extended to handle the many other {{age}} templates.
        {{Age in days}}                age_days
-- However, calendar functions will be needed in many areas, so this may be
        {{Age in years and months}}     age_ym
-- superseded by some other system, perhaps using functions from the PHP host.
        {{Gregorian serial date}}       gsd_ymd
Calendar functions will be needed in many areas, so this may be superseded
by some other system, perhaps using PHP functions accessed via mw.
]]


local MINUS = '−'  -- Unicode U+2212 MINUS SIGN (UTF-8: e2 88 92)
local MINUS = '−'  -- Unicode U+2212 MINUS SIGN


local function number_name(number, singular, plural, sep)
local function number_name(number, singular, plural, sep)
    -- Return the given number, converted to a string, with the
    -- separator (default space) and singular or plural name appended.
     plural = plural or (singular .. 's')
     plural = plural or (singular .. 's')
     sep = sep or ' '
     sep = sep or ' '
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end
end


local function strip(text)
local function strip_to_nil(text)
     -- If text is a string, return its content with no leading/trailing
     -- If text is a non-blank string, return its content with no leading
     -- whitespace. Otherwise return nil (a nil argument gives a nil result).
     -- or trailing whitespace.
    -- Otherwise return nil (a nil or empty string argument gives a nil
    -- result, as does a string argument of only whitespace).
     if type(text) == 'string' then
     if type(text) == 'string' then
         return text:match("^%s*(.-)%s*$")
         local result = text:match("^%s*(.-)%s*$")
        if result ~= '' then
            return result
        end
     end
     end
    return nil
end
end


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     end
     end
     return month_days[month]
     return month_days[month]
end
-- A table to get current year/month/day (UTC), but only if needed.
local current = setmetatable({}, {
        __index = function (self, key)
            local d = os.date('!*t')
            self.year = d.year
            self.month = d.month
            self.day = d.day
            return rawget(self, key)
        end
    })
local function date_component(named, positional, component)
    -- Return the first of the two arguments that is not nil and is not empty.
    -- If both are nil, return the current date component, if specified.
    -- The returned value is nil or is a number.
    -- This translates empty arguments passed to the template to nil, and
    -- optionally replaces a nil argument with a value from the current date.
    named = strip_to_nil(named)
    if named then
        return tonumber(named)
    end
    positional = strip_to_nil(positional)
    if positional then
        return tonumber(positional)
    end
    if component then
        return current[component]
    end
    return nil
end
local function gsd(year, month, day)
    -- Return the Gregorian serial day (an integer >= 1) for the given date,
    -- or return nil if the date is invalid (only check that year >= 1).
    -- This is the number of days from the start of 1 AD (there is no year 0).
    -- This code implements the logic in [[Template:Gregorian serial date]].
    if year < 1 then
        return nil
    end
    local floor = math.floor
    local days_this_year = (month - 1) * 30.5 + day
    if month > 2 then
        if is_leap_year(year) then
            days_this_year = days_this_year - 1
        else
            days_this_year = days_this_year - 2
        end
        if month > 8 then
            days_this_year = days_this_year + 0.9
        end
    end
    days_this_year = floor(days_this_year + 0.5)
    year = year - 1
    local days_from_past_years = year * 365
        + floor(year / 4)
        - floor(year / 100)
        + floor(year / 400)
    return days_from_past_years + days_this_year
end
end


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     end
     end
}
}
function Date:__lt(rhs)
    -- Return true if self < rhs.
    if self.year < rhs.year then
        return true
    end
    if self.year == rhs.year then
        if self.month < rhs.month then
            return true
        end
        if self.month == rhs.month then
            return self.day < rhs.day
        end
    end
    return false
end


function Date:set_current()
function Date:set_current()
     -- Set date from current time (UTC) and return self.
     -- Set date from current time (UTC) and return self.
    local d = os.date('!*t')
     self.year = current.year
     self.year = d.year
     self.month = current.month
     self.month = d.month
     self.day = current.day
     self.day = d.day
     self.isvalid = true
     self.isvalid = true
     return self
     return self
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     end
     end
     return self
     return self
end
function Date:less_than(rhs)
    -- Set true if self < rhs.
    if self.year < rhs.year then
        return true
    end
    if self.year == rhs.year then
        if self.month < rhs.month then
            return true
        end
        if self.month == rhs.month then
            return self.day < rhs.day
        end
    end
    return false
end
end


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     -- Difference is negative if the second date is older than the first.
     -- Difference is negative if the second date is older than the first.
     local isnegative
     local isnegative
     if date2:less_than(date1) then
     if date2 < date1 then
         isnegative = true
         isnegative = true
         date1, date2 = date2, date1
         date1, date2 = date2, date1
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local function error_wikitext(text)
local function error_wikitext(text)
     -- Return message for display when template parameters are invalid.
     -- Return message for display when template parameters are invalid.
    -- TODO Get opinions on whether the prefix and category are suitable.
     local prefix = '[[Module talk:Age|Module error]]:'
     local prefix = '[[Module talk:Age|Module error]]:'
     local cat = '[[Category:Age error]]'
     local cat = '[[Category:Age error]]'
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end
end


local function get_parms(pframe)
local function age_days(frame)
     -- Return date1, date2 from parameters to template.
     -- Return age in days between two given dates, or
     -- If date1 is missing or invalid, the returned date1 is nil.
    -- between given date and current date.
     -- If date2 is missing, the returned date2 is the current date.
     -- This code implements the logic in [[Template:Age in days]].
     -- If date2 is invalid, the returned date2 is nil.
     -- Like {{Age in days}}, a missing argument is replaced from the current
     local args = {} -- arguments passed to template
    -- date, so can get a bizarre mixture of specified/current y/m/d.
    local args = frame:getParent().args
    local year1  = date_component(args.year1 , args[1], 'year' )
    local month1 = date_component(args.month1, args[2], 'month')
    local day1  = date_component(args.day1  , args[3], 'day'  )
    local year2  = date_component(args.year2 , args[4], 'year' )
     local month2 = date_component(args.month2, args[5], 'month')
    local day2  = date_component(args.day2  , args[6], 'day'  )
    local gsd1 = gsd(year1, month1, day1)
    local gsd2 = gsd(year2, month2, day2)
    if gsd1 and gsd2 then
        local sign = ''
        local result = gsd2 - gsd1
        if result < 0 then
            sign = MINUS
            result = -result
        end
        return sign .. tostring(result)
    end
    return error_wikitext('Cannot handle dates before the year 1 AD')
end
 
local function age_ym(frame)
    -- Return age in years and months between two given dates, or
    -- between given date and current date.
     local args = frame:getParent().args
    local fields = {}
     for i = 1, 6 do
     for i = 1, 6 do
         args[i] = strip(pframe.args[i])
         fields[i] = strip_to_nil(args[i])
     end
     end
     local date1, date2
     local date1, date2
     if args[1] and args[2] and args[3] then
     if fields[1] and fields[2] and fields[3] then
         date1 = Date:new():set_ymd(args[1], args[2], args[3])
         date1 = Date:new():set_ymd(fields[1], fields[2], fields[3])
        if not date1.isvalid then
    end
            date1 = nil
    if not (date1 and date1.isvalid) then
         end
         return error_wikitext('Need date: year, month, day')
     end
     end
     if args[4] and args[5] and args[6] then
     if fields[4] and fields[5] and fields[6] then
         date2 = Date:new():set_ymd(args[4], args[5], args[6])
         date2 = Date:new():set_ymd(fields[4], fields[5], fields[6])
         if not date2.isvalid then
         if not date2.isvalid then
             date2 = nil
             return error_wikitext('Second date should be year, month, day')
         end
         end
     else
     else
         date2 = Date:new():set_current()
         date2 = Date:new():set_current()
     end
     end
     return date1, date2
     return DateDiff:new():set(date1, date2):age_ym()
end
end


local function age_ym(frame)
local function gsd_ymd(frame)
     local date1, date2 = get_parms(frame:getParent())
    -- Return Gregorian serial day of the given date, or the current date.
     if date1 then
    -- Like {{Gregorian serial date}}, a missing argument is replaced from the
        if not date2 then
    -- current date, so can get a bizarre mixture of specified/current y/m/d.
            return error_wikitext('Second date should be year, month, day')
    -- This accepts positional arguments, although the original template does not.
        end
     local args = frame:getParent().args
        local diff = DateDiff:new():set(date1, date2)
     local year  = date_component(args.year , args[1], 'year' )
         return diff:age_ym()
    local month = date_component(args.month, args[2], 'month')
    local day  = date_component(args.day  , args[3], 'day' )
    local result = gsd(year, month, day)
    if result then
         return tostring(result)
     end
     end
     return error_wikitext('Need date: year, month, day')
     return error_wikitext('Cannot handle dates before the year 1 AD')
end
end


return { age_ym = age_ym }
return { age_days = age_days, age_ym = age_ym, gsd = gsd_ymd }
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