Module:Age: Difference between revisions
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}}) |
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-- Code | --[[ Code for some date functions, including implementations of: | ||
{{Age in days}} age_days | |||
{{Age in years and months}} age_ym | |||
{{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Calendar functions will be needed in many areas, so this may be superseded | |||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 | 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 | local function strip_to_nil(text) | ||
-- If text is a string, return its content with no leading | -- 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 | ||
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. | ||
self.year = current.year | |||
self.year = | self.month = current.month | ||
self.month = | self.day = current.day | ||
self.day = | |||
self.isvalid = true | self.isvalid = true | ||
return self | return self | ||
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end | end | ||
return self | return self | ||
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 | 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. | ||
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 | local function age_days(frame) | ||
-- Return | -- Return age in days between two given dates, or | ||
-- | -- between given date and current date. | ||
-- | -- This code implements the logic in [[Template:Age in days]]. | ||
-- | -- Like {{Age in days}}, a missing argument is replaced from the current | ||
local args = {} | -- 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 | ||
fields[i] = strip_to_nil(args[i]) | |||
end | end | ||
local date1, date2 | local date1, date2 | ||
if | if fields[1] and fields[2] and fields[3] then | ||
date1 = Date:new():set_ymd( | date1 = Date:new():set_ymd(fields[1], fields[2], fields[3]) | ||
end | |||
if not (date1 and date1.isvalid) then | |||
return error_wikitext('Need date: year, month, day') | |||
end | end | ||
if | if fields[4] and fields[5] and fields[6] then | ||
date2 = Date:new():set_ymd( | date2 = Date:new():set_ymd(fields[4], fields[5], fields[6]) | ||
if not date2.isvalid then | if not date2.isvalid then | ||
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 | local function gsd_ymd(frame) | ||
local | -- Return Gregorian serial day of the given date, or the current date. | ||
-- Like {{Gregorian serial date}}, a missing argument is replaced from the | |||
-- current date, so can get a bizarre mixture of specified/current y/m/d. | |||
-- This accepts positional arguments, although the original template does not. | |||
local args = frame:getParent().args | |||
local year = date_component(args.year , args[1], 'year' ) | |||
return | 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(' | 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 } |