Module:Japanese calendar
This module is used to calculate dates in the Japanese calendar. It defines an "era" class which is designed to be called from other Lua modules, and it also contains several functions to export Japanese calendar data directly to Wikipedia pages through #invoke.
Usage
Through #invoke
{{#invoke:Japanese calendar|function_name|year=year|era=article name or kanji|previous=yes|next=yes}}
The function name specifies how the data should be outputted. The year
and era
parameters determine what era and year the module outputs. The next
and previous
parameters tell the module to return data for the next or previous era, rather than the one specified. If a combination of parameters is invalid the module will usually output nothing. However, if both the next
and previous
parameters are specified it will output an error.
- Year and era
The year
parameter is the year in the Gregorian calendar. The era
parameter can either be the article name for that era, or the era's name in kanji. (Transcribed English era names can usually be used, but will not work if they are ambiguous.) Either year
or era
must be specified. If both are specified, the module defaults to using era
to get the era data. This enables output of the last year of the previous era (for example, Shōwa 64 is the same year as Heisei 1).
Code | Output |
---|---|
{{#invoke:Japanese calendar|link|year=1950}} |
Shōwa |
{{#invoke:Japanese calendar|link|era=Shōwa period}} |
Shōwa |
{{#invoke:Japanese calendar|link|era=昭和}} |
Shōwa |
{{#invoke:Japanese calendar|link|era=Shōwa}} |
|
{{#invoke:Japanese calendar|link_year|year=1989}} |
Heisei 1 |
{{#invoke:Japanese calendar|link_year|year=1989|era=Shōwa period}} |
Shōwa 64 |
{{#invoke:Japanese calendar|link_year|year=1990}} |
Heisei 2 |
{{#invoke:Japanese calendar|link_year|year=1990|era=Shōwa period}} |
- Functions
Code | Description | Example |
---|---|---|
baseyear |
The first year of the specified era. | {{#invoke:Japanese calendar|baseyear|era=Heisei}} →
|
endyear |
The last year of the specified era. | {{#invoke:Japanese calendar|endyear|era=Shōwa period}} → 1989
|
year |
The year for the specified era, without the era name. Defaults to the newer era, if more than one is applicable. | {{#invoke:Japanese calendar|year|year=1989}} → 1
|
kanjiyear |
The same as year , but in kanji. The first year of an era is changed to the kanji 元, and the others are changed to full-width numbers. |
{{#invoke:Japanese calendar|kanjiyear|year=1989}} → 元
|
article |
The Wikipedia article for the era, unlinked. | {{#invoke:Japanese calendar|article|year=1950}} → Shōwa period
|
label |
The name of the era. Same as article for undisambiguated titles. |
{{#invoke:Japanese calendar|label|year=1950}} → Shōwa
|
link |
A link to the Wikipedia article of the specified era. | {{#invoke:Japanese calendar|link|year=1950}} → Shōwa
|
kanji |
The kanji for the specified era. | {{#invoke:Japanese calendar|kanji|year=1950}} → 昭和
|
label_year |
label followed by year |
{{#invoke:Japanese calendar|label_year|year=1989}} → Heisei 1
|
link_year |
link followed by year |
{{#invoke:Japanese calendar|link_year|year=1989}} → Heisei 1
|
label_kanjiyear |
label followed by kanjiyear |
{{#invoke:Japanese calendar|label_kanjiyear|year=1989}} → Heisei 元
|
link_kanjiyear |
link followed by kanjiyear |
{{#invoke:Japanese calendar|link_kanjiyear|year=1989}} → Heisei 元
|
- Next, previous and old
If the next
parameter is specified, the module outputs the data for the subsequent era; if the previous
parameter is specified it outputs the data for the previous one. If the old
parameter is specified, the module outputs the data for the "old" era. This is the same as the current era unless the year is set to the first year of the specified era. If this is the case, then old
outputs the data for the previous era. However, if the module could not find a valid previous era then the data for the current era is returned.
Code | Output |
---|---|
{{#invoke:Japanese calendar|baseyear|era=Shōwa period}} |
1926 |
{{#invoke:Japanese calendar|baseyear|era=Shōwa period|next=yes}} |
1989 |
{{#invoke:Japanese calendar|baseyear|era=Shōwa period|previous=yes}} |
1912 |
{{#invoke:Japanese calendar|baseyear|era=Shōwa period|old=yes}} |
1926 |
{{#invoke:Japanese calendar|link|year=1880}} |
Meiji |
{{#invoke:Japanese calendar|link|year=1880|next=yes}} |
Taishō |
{{#invoke:Japanese calendar|link|year=1880|previous=yes}} |
Keiō |
{{#invoke:Japanese calendar|link|year=1880|old=yes}} |
Meiji |
{{#invoke:Japanese calendar|link_year|year=1926}} |
Shōwa 1 |
{{#invoke:Japanese calendar|link_year|year=1926|old=yes}} |
Taishō 15 |
{{#invoke:Japanese calendar|link_year|year=1927}} |
Shōwa 2 |
{{#invoke:Japanese calendar|link_year|year=1927|old=yes}} |
Shōwa 2 |
From another Lua module
First of all, the era class must be loaded, like this:
local era = require( 'Module:Japanese calendar' ).era
Once the class is loaded, you can make a new era object using era:new()
:
local myEra = era:new{ year = year, era = article name or kanji }
Either year
or era
must be specified. It is also possible to use an index
field, corresponding to the index of Module:Japanese calendar/data, but this is for internal use only and will change as new eras are added.
- Properties
Era objects have a number of properties. Their values might be nil
if the module did not have enough information to process them, or the values could be false
if they correspond to an invalid era. You can specify properties with the dot syntax:
local article = myEra.article
The properties are as follows:
gregorianYear
: the year in the Gregorian calendar. Same as the input year.startYear
: the first year of the specified era.endYear
: the last year of the specified era.eraYear
: the year of the specified era, without the era name.eraYearKanji
: a string representing the era year in kanji. The first year of an era is changed to the kanji 元, and the others are changed to full-width numbers. Note: even though the output may often look like a number, it will always be a string value.article
: the Wikipedia article for the era, unlinked.label
: the name of the era. Same asarticle
unless the article title is disambiguated.kanji
: the name of the era in kanji.
- Methods
Era objects have three methods. Methods can be specified with the colon syntax:
local nextEra = myEra:getNextEra()
The methods are as follows:
era:getNextEra()
- gets the era object for the next era. Returnsnil
if it doesn't exist.era:getPreviousEra()
- gets the era object for the previous era. Returnsnil
if it doesn't exist.era:getOldEra()
- gets the era object for the "old" era. This is the same as the current era object unless eraYear equals 1. If eraYear equals 1 then this returns the era object for the previous era. If the module could not find a valid previous era object then the current era object is returned.
-- This module defines an "era" class for processing eras in the Japanese calendar. -- It also contains functions to export the class properties to #invoke. local eras = mw.loadData( 'Module:Japanese calendar/data' ) local halfToFull = require( 'Module:Convert character width' ).full -- Converts half-width characters to full-width characters. -------------------------------------------------------------------- -- Helper functions -------------------------------------------------------------------- local function yearToEraIndex( year ) year = tonumber( year ) if type( year ) ~= 'number' then return end for i, t in ipairs( eras ) do if year > t.startYear then return i elseif year == t.startYear then if eras[ i + 1 ] and eras[ i + 1 ].startYear == t.startYear then -- This checks for occasions when there were more than two eras in the same year. At the moment, that only applies to the year 686. return i + 1 else return i end end end end local function textToEraIndex( s ) if not s or s == '' then return end for i, t in ipairs( eras ) do if s == t.article or s == t.kanji then return i end end end -------------------------------------------------------------------- -- Era class definition -------------------------------------------------------------------- local era = {} era.__index = era function era:new( init ) init = type( init ) == 'table' and init or {} local obj = {} -- Grab the data from the init table. obj.gregorianYear = tonumber( init.year ) local initText = type( init.era ) == 'string' and init.era or nil local initIndex = tonumber( init.index ) if not ( initIndex and initIndex >= 1 and math.floor( initIndex ) == initIndex and initIndex ~= math.huge ) then -- Check that initIndex is a positive integer. initIndex = nil end -- Calculate the era data from the input. First we find the era from the era index, although this is only supposed -- to be for internal use. Next we find the era from the era name or the kanji if possible, as this allows us to -- specify the last year of one era rather than the first year of the next one, if that is the desired behaviour. local eraIndex if initIndex then eraIndex = initIndex elseif initText then eraIndex = textToEraIndex( initText ) elseif obj.gregorianYear then eraIndex = yearToEraIndex( obj.gregorianYear ) end -- If the data entry was found for the era, process it and add it to the object. if not eraIndex then return end local eraData = eras[ eraIndex ] if not eraData or not eraData.article or eraData.article == '' then return end -- Exit if we are not dealing with a valid era. obj.startYear = eraData.startYear obj.endYear = eraData.endYear obj.article = eraData.article obj.kanji = eraData.kanji obj.label = eraData.label -- Create a link to the era article if possible. if obj.label and obj.article then obj.link = mw.ustring.format( '[[%s|%s]]', obj.article, obj.label ) elseif obj.article then obj.link = mw.ustring.format( '[[%s]]', obj.article ) end -- Allow matching years to different eras, but only for the first year of the next era. For example, Taisho 15 is also Showa 1, but there is no such thing as Taisho 16. -- So, the code era:new{ year = 1926, era = "Taishō" } will return an object with an eraYear of 15, and era:new{ year = 1926 } will return an object with an eraYear of 1. local nextEraData = eras[ eraIndex - 1 ] local nextStartYear = nextEraData and nextEraData.startYear if obj.gregorianYear and ( -- If there is a later era, only allow the first year of that era or an earlier year. not nextStartYear or ( nextStartYear and obj.gregorianYear <= nextStartYear ) ) and obj.gregorianYear >= obj.startYear -- Don't allow negative years. and obj.article ~= '' -- Don't allow periods between named eras. and ( obj.endYear and obj.gregorianYear <= obj.endYear or true ) -- If this era has an end year, don't allow years that are greater than the end year. then obj.eraYear = obj.gregorianYear - obj.startYear + 1 if obj.eraYear == 1 then obj.eraYearKanji = '元' else obj.eraYearKanji = halfToFull( obj.eraYear ) end end -- Make sure obj.label is available even if it is the same as the article name. obj.label = obj.label or obj.article -- Add methods to get the next and previous eras. function obj:getNextEra() if not eraIndex then return end return era:new{ index = eraIndex - 1, year = obj.gregorianYear } end function obj:getPreviousEra() if not eraIndex then return end return era:new{ index = eraIndex + 1, year = obj.gregorianYear } end -- Gets the era object for the "old" era. In most cases this is the same as the current era object, but -- if the era year for the current object is 1, this method will return the era object for the previous -- era. If the method can't find a valid previous era it will return the object for the current era. function obj:getOldEra() if obj.eraYear == 1 then local prevEra = obj:getPreviousEra() if prevEra then return prevEra else return obj end else return obj end end return setmetatable( obj, { __index = self }) end -------------------------------------------------------------------- -- Interface for old Japanese calendar templates -------------------------------------------------------------------- local function getStartYear( obj ) return obj.startYear end local function getEndYear( obj ) return obj.endYear end local function getEraYear( obj ) return obj.eraYear end local function getEraYearKanji( obj ) return obj.eraYearKanji end local function getArticle( obj ) return obj.article end local function getLabel( obj ) return obj.label end local function getLink( obj ) return obj.link end local function getKanji( obj ) return obj.kanji end local function getLabelAndEraYear( obj, kanji ) local eraYear = kanji and obj.eraYearKanji or obj.eraYear if obj.label and eraYear then return mw.ustring.format( '%s %s', obj.label, tostring( eraYear ) ) end end local function getLinkAndEraYear( obj, kanji ) local eraYear = kanji and obj.eraYearKanji or obj.eraYear if obj.link and eraYear then return mw.ustring.format( '%s %s', obj.link, tostring( eraYear ) ) end end local function getLabelAndEraYearKanji( obj ) return getLabelAndEraYear( obj, true ) end local function getLinkAndEraYearKanji( obj ) return getLinkAndEraYear( obj, true ) end -- Process the arguments from #invoke. local function makeWrapper( func ) return function( frame ) -- If called via #invoke, use the args passed into the invoking -- template, or the args passed to #invoke if any exist. Otherwise -- assume args are being passed directly in from the debug console -- or from another Lua module. local origArgs if frame == mw.getCurrentFrame() then origArgs = frame:getParent().args for k, v in pairs( frame.args ) do origArgs = frame.args break end else origArgs = frame end -- Trim whitespace and remove blank arguments. local args = {} for k, v in pairs( origArgs ) do if type( v ) == 'string' then v = mw.text.trim( v ) end if v ~= '' then args[k] = v end end local myEra local otherEraArgs = {} table.insert( otherEraArgs, args.next ) table.insert( otherEraArgs, args.previous ) table.insert( otherEraArgs, args.old ) if #otherEraArgs > 1 then return '<strong class="error">[[Module:Japanese calendar]] error: you can only specify one parameter out of "next", "previous" and "old".</strong>' elseif args.next then myEra = era:new( args ):getNextEra() elseif args.previous then myEra = era:new( args ):getPreviousEra() elseif args.old then myEra = era:new( args ):getOldEra() else myEra = era:new( args ) end return myEra and func( myEra ) or '' end end -------------------------------------------------------------------- -- Return the era class and the template interface -------------------------------------------------------------------- return { era = function () return era end, -- Accessor function for getting the era class from other modules. baseyear = makeWrapper( getStartYear ), endyear = makeWrapper( getEndYear ), year = makeWrapper( getEraYear ), kanjiyear = makeWrapper( getEraYearKanji ), article = makeWrapper( getArticle ), label = makeWrapper( getLabel ), link = makeWrapper( getLink ), kanji = makeWrapper( getKanji ), label_year = makeWrapper( getLabelAndEraYear ), link_year = makeWrapper( getLinkAndEraYear ), label_kanjiyear = makeWrapper( getLabelAndEraYearKanji ), link_kanjiyear = makeWrapper( getLinkAndEraYearKanji ) }