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bsd>Jarekt
(add getLabel function)
 
(1版 をインポートしました)
 
(2人の利用者による、間の4版が非表示)
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  |_|  |_|\___/ \__,_|\__,_|_|\___(_)\____\___/|_|  \___|
                                                          
                                                          
This module is intended as collection of core functions shared among several Lua modules  
Core is a meta-module that consists of common and useful Lua functions that can
creating infobox templates on Commons.  
be used in many Lua scripts. It was writen as a core of several Lua  
modules for creating file infobox templates on Commons. Many of the functions
are bare-bones versions of full functions found in other modules.


Authors and maintainers:
Authors and maintainers:
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------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- Based on frame structure create "args" table with all the input parameters.
--[[
-- All inputs are not not case-sensitive and underscored are treated the same  
Based on frame structure create "args" table with all the input parameters:
-- way as speces. Input values are trimmed and empty string are converted to  
* table keys - equivalent to template parameters are converted to lower case
-- nils. If "lang" is not provided than we substitute user's prefered language.
                so they will not be case-sensitive.
                Also underscored are treated the same way as speces.  
* table values - input values are trimmed (whitespaces removed from the beggining
                and the end) and empty string are converted to nils.  
If "lang" is not provided than we substitute user's prefered language.
 
This function collects inputs from both frame and frame's parent. See
https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#frame:getParent .
If both structures have the same field than value from "frame" takes priority.
 
Inputs:
1) frame - frame objects see below for details
https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#frame-object
 
See also: Module:Arguments on enWiki - which is much larger single purpose module
]]
function core.getArgs(frame)
function core.getArgs(frame)
local function normalize_input_args(input_args, output_args)
local function normalize_input_args(input_args, output_args)
for name, value in pairs( input_args ) do  
for name, value in pairs( input_args ) do  
value = string.gsub(value, "^%s*(.-)%s*$", "%1") -- trim whitespaces from the beggining and the end of the string
value = mw.text.trim(value) -- trim whitespaces from the beggining and the end of the string
if value ~= '' then -- nuke empty strings
if value ~= '' then -- nuke empty strings
if type(name)=='string' then  
if type(name)=='string' then  
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------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- code equivalent to https://commons.wikimedia.org/wiki/Template:LangSwitch
--[[
function core.langSwitch(list,lang)
Simplified code equivalent to https://commons.wikimedia.org/wiki/Template:LangSwitch
 
Example usage:
  text = langSwitch({en='text in english', pl='tekst po polsku'}, lang)
 
Inputs:
  1: args - table with translations by language
  2: lang - desired language (often user's native language)
 
Outputs:
  1: label - returned label
  2: lang  - language of the label (langSwitchWithLang only)
]]
function core.langSwitchWithLang(args, lang)
local langList = mw.language.getFallbacksFor(lang)
local langList = mw.language.getFallbacksFor(lang)
table.insert(langList,1,lang)
table.insert(langList,1,lang)
for i,language in ipairs(langList) do
for i,language in ipairs(langList) do
if list[language] then
if args[language] then
return list[language]
return args[language], language
end
end
end
end
end
function core.langSwitch(args, lang)
local label, lang = core.langSwitchWithLang(args, lang)
return label
end
------------------------------------------------------------------------------
--[[
display a language followed by a message. Like "English: Hello" with extensive HTML marking
Code equivalent to https://commons.wikimedia.org/wiki/Template:Description
Inputs:
  1) text_lang - language code for the above text, also used as a name of the CSS formating class
  2) text - description text to display
  3) args -  additional optional arguments. Numbers in perenthesis are parameter numbers in the original template.
  * hover    - (3) hover aka mouseover aka tooltip text
  * lang_tag - (4) standard code for lang tag in HTML (optional, default is same as text_lang)
  * ext      - (5) extension text shown after the language name before colon (optional, default is empty)
      * inline - Optional, default is false. When set to true, forces the template to be displayed
            inline, so that it does not break the current paragraph (that makes possible to put several
        descriptions side by side on a single line)  
]]
function core.langWrapper(text_lang, text, args)
local dir, space, colon, lang_name, hover
local inline    = core.yesno(args.inline, false) and 'inline' or nil
if mw.language.isKnownLanguageTag(text_lang) then -- supported language
local langObj = mw.language.new( text_lang )
dir      = langObj:getDir()          -- text direction
space    = mw.message.new( "Word-separator" ):inLanguage(text_lang):plain()
colon    = mw.message.new( "Colon" ):inLanguage(text_lang):plain()
hover    = mw.language.fetchLanguageName( text_lang, args.user_lang or 'en')
lang_name = mw.language.fetchLanguageName( text_lang, text_lang)
lang_name = langObj:ucfirst(lang_name)
else -- unsuported language
local RTL_LUT = {['fa-af']=1, prd=1, ydd=1}
dir  = (RTL_LUT[text_lang]==1 or text_lang:gsub('-arab', '')~=text_lang) and 'rtl' or 'ltr'
space = ' '
colon = ':'
hover = args.hover
lang_name = text_lang or 'Unknown'
end
lang_name = args.lang_name or lang_name-- user provided args.lang_name takes presedent
lang_name = '<b>' .. lang_name .. (args.ext or '') .. colon .. '</b>'
-- create HTML
local ltag = mw.html.create('span')  -- bold language name string
:addClass('language')  -- class: "language"
:addClass(text_lang)  -- class:  "en", "de" etc.
:attr('title', hover)  -- add hover aka mouseover aka tooltip text
:wikitext(lang_name)
local dtag = mw.html.create('div')
:addClass('description')      -- div.description is tracked by mw:Extension:CommonsMetadata
:addClass('mw-content-'..dir) -- mw-content-rtl and mw-content-ltr are defined in mediawiki-code (https://gerrit.wikimedia.org/r/c/mediawiki/core/+/208332)
:addClass(text_lang)          -- not sure where "en", "de" etc. are defined
:attr('dir', dir)
:attr('lang', text_lang)
:css('display', inline)
:wikitext(tostring(ltag) .. space .. text)
return tostring(dtag)
end
end


------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- Function allowing for consistent treatment of boolean-like wikitext input.
--[[
-- It works similarly to Module:Yesno
Function allowing for consistent treatment of boolean-like wikitext input.
Inputs:
  1) val - value to be evaluated, outputs as a function of values:
true  : true  (boolean), 1 (number), or strings: "yes", "y", "true", "1"
false : false (boolean), 0 (number), or strings: "no", "n", "false", "0"
  2) default - value to return otherwise
See Also: It works similarly to Module:Yesno
]]
function core.yesno(val, default)
function core.yesno(val, default)
if type(val) == 'boolean' then
if type(val) == 'boolean' then
return val
return val
elseif type(val) == 'number' then
elseif type(val) == 'number' then
if val==1 then  
val = tostring(val)
return true
end
elseif val==0 then
if type(val) == 'string' then
return false
local LUT = {
yes=true , y=true , ['true'] =true , t=true , ['1']=true , on =true,
no =false, n=false, ['false']=false, f=false, ['0']=false, off=false }
    val = LUT[mw.ustring.lower(val)]  -- put in lower case
    if (val~=nil) then
return val
end
end
elseif type(val) == 'string' then
    val = mw.ustring.lower(val)  -- put in lower case
    if val == 'no'  or val == 'n' or val == 'false' or val == '0' then
        return false
    elseif val == 'yes' or val == 'y' or val == 'true'  or val == '1' then
        return true
    end
     end
     end
     return default
     return default
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------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- read Commons Data:SOMENAME.tab dataset and look for message identified by a  
--[[
-- "key" in a language "lang". See editAtWikidata as an example.
Read Commons Data:SOMENAME.tab dataset and look for message identified by a  
"key" in a language "lang". See editAtWikidata for an example. It uses
https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#mw.ext.data
 
Inputs:
1) dataset - name of commons page in "data" namespace. for example "I18n/EditAt.tab"
for c:Data:I18n/EditAt.tab
2) key - which message to pull
3) lang - desired language of the message
Output: message as a string
]]
function core.formatMessage(dataset, key, lang)
function core.formatMessage(dataset, key, lang)
for _, row in pairs(mw.ext.data.get(dataset, lang).data) do
for _, row in pairs(mw.ext.data.get(dataset, lang).data) do
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end
end


-------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- Assembles the "Edit at Wikidata" pen icon and returns it as wikitext string.
--[[
-- Dependencies: Data:I18n/EditAt.tab
Assembles the "Edit at Wikidata" pen icon with a link to Wikidata page or specific
property and returns it as wikitext string.
Inputs:
  1) entityID - wikidata entity object for a given page (output of wikibase.getEntity( id ))
  2) propertyID - string like 'P31' so the link will point to that specific property. Use ""
    to link to the whole page.
  3) lang - language of the "Edit at Wikidata"  message
Dependencies: Data:I18n/EditAt.tab
See Also: en:Module:EditAtWikidata
]]
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
function core.editAtWikidata(entityID, propertyID, lang)
function core.editAtWikidata(entityID, propertyID, lang)
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end
end


-------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- Assembles the "Edit at SDC" pen icon and returns it as wikitext string.
--[[
-- Dependencies: Data:I18n/EditAt.tab
Assembles the "Edit at SDC" pen icon with a link to a property in SDC part of the current file
-------------------------------------------------------------------------------
page, and returns it as wikitext string.
Inputs:
  2) propertyID - string like 'P31' so the link will point to that specific property. Use 'ooui-php-4'
    to link to the label section.
  3) lang - language of the "Edit at Wikidata"  message
Dependencies: Data:I18n/EditAt.tab
See Also: en:Module:EditAtWikidata
]]
function core.editAtSDC(propertyID, lang)
function core.editAtSDC(propertyID, lang)
local msg  = core.formatMessage('I18n/EditAt.tab', 'EditAtSDC', lang)
local msg  = core.formatMessage('I18n/EditAt.tab', 'EditAtSDC', lang)
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-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
function core.getLabel(id, userLang)
--[[
-- code equivalent to require("Module:Wikidata label")._getLabel
This function returns a label translated to desired language, created based on wikidata
Code equivalent to require("Module:Wikidata label")._getLabel
 
Inputs:
1: item - wikidata's item's q-id or entity class
2: userLang - desired language of the label
]]
function core.getLabel(item, userLang)
local label, link
local label, link
-- build language fallback list
-- build language fallback list
local langList = mw.language.getFallbacksFor(userLang)
local langList = mw.language.getFallbacksFor(userLang)
table.insert(langList, 1, userLang)
table.insert(langList, 1, userLang)  
-- get label
for _, lang in ipairs(langList) do  -- loop over language fallback list looking for label in the specific language
for _, lang in ipairs(langList) do  -- loop over language fallback list looking for label in the specific language
label = mw.wikibase.getLabelByLang(id, lang)
label = mw.wikibase.getLabelByLang(item, lang)
if label then break end                    -- label found and we are done
if label then break end                    -- label found and we are done
end
end
label = label or item -- fallback value
-- get link
for _, lang in ipairs(langList) do  -- loop over language fallback list looking for label in the specific language
for _, lang in ipairs(langList) do  -- loop over language fallback list looking for label in the specific language
link =  mw.wikibase.getSitelink(id, lang .. 'wiki')
link =  mw.wikibase.getSitelink(item, lang .. 'wiki')
if link then
if link then
link = mw.ustring.format('w:%s:%s', lang, link)
link = mw.ustring.format('w:%s:%s', lang, link)
break
break
end
end
end
end
link = link or ('d:'..id)
link = link or 'd:'..item -- fallback value
label = label or id
-- look for description
    return '[['..link..'|'..label..']]'
local desc = mw.wikibase.getDescription(item)
if desc then  -- add description if we have one
desc  = mw.text.nowiki(desc) -- add description as hover text
label = '<span title="' .. desc .. '">' .. label .. '</span>'
end
  return '[['..link..'|'..label..']]'
end
 
-------------------------------------------------------------------------------
--[[
Core component of many "get property value" functions
Example: (core.parse_statements(entity:getBestStatements( prop ), nil) or {nil})[1] would
return the first best statement
Inputs:
1: statements - can be provided by:
  * entity:getBestStatements( prop )
  * entity:getAllStatements( prop )
  * mw.wikibase.getBestStatements( item, prop )
  * mw.wikibase.getAllStatements( item, prop )
2: lang - language code (like "en"), if provided than item IDs will be
    changed to a label
Output:
* table of strings or nil
]]
function core.parseStatements(statements, lang)
local output = {}
for _, statement in ipairs(statements) do
if (statement.mainsnak.snaktype == "value") and (statement.rank ~= 'deprecated')  then
table.insert(output, core.parseSnak(statement.mainsnak, lang))
end
end
if #output==0 then return nil end
return output
end
 
-------------------------------------------------------------------------------
--[[
parse part of the statement called "snak"
 
Inputs:
1: snak -
2: lang - language code (like "en"), if provided than item IDs will be
    changed to a label
Output:
* string
]]
function core.parseSnak(snak, lang)
local val = snak.datavalue.value
if val.id then
val = val.id
if lang ~= nil then
val = core.getLabel(val, lang)
end
elseif val.text then
val = val.text
elseif val.amount then
val = tonumber(val.amount)
elseif val.time then -- handle most dates (use [[Module:Wikidata date]] for the rest
local gregorian = 'http://www.wikidata.org/entity/Q1985727'
if (val.calendarmodel==gregorian) and (mw.ustring.sub(val.time,1,1)=='+') and val.precision >= 9 then
local trim = 3*math.min(val.precision,11) - 22 -- day (11)->11, month (10)->8, year (9)->5
val = mw.ustring.sub(val.time, 2, trim)    -- return YYYY-MM-DD, YYYY-MM or YYYY depending on precission
end
end
return val
end
end


return core
return core

2023年5月8日 (月) 09:09時点における最新版

このモジュールについての説明文ページを モジュール:Core/doc に作成できます

--[[  
  __  __           _       _         ____               
 |  \/  | ___   __| |_   _| | ___ _ / ___|___  _ __ ___ 
 | |\/| |/ _ \ / _` | | | | |/ _ (_) |   / _ \| '__/ _ \
 | |  | | (_) | (_| | |_| | |  __/_| |__| (_) | | |  __/
 |_|  |_|\___/ \__,_|\__,_|_|\___(_)\____\___/|_|  \___|
                                                        
Core is a meta-module that consists of common and useful Lua functions that can 
be used in many Lua scripts. It was writen as a core of several Lua 
modules for creating file infobox templates on Commons. Many of the functions
are bare-bones versions of full functions found in other modules.

Authors and maintainers:
* User:Jarekt  
]]

local core = {}

------------------------------------------------------------------------------
--[[
Based on frame structure create "args" table with all the input parameters:
 * table keys - equivalent to template parameters are converted to lower case 
                so they will not be case-sensitive.
                Also underscored are treated the same way as speces. 
 * table values - input values are trimmed (whitespaces removed from the beggining 
                and the end) and empty string are converted to nils. 
If "lang" is not provided than we substitute user's prefered language.

This function collects inputs from both frame and frame's parent. See 
https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#frame:getParent .
If both structures have the same field than value from "frame" takes priority.

Inputs:
	1) frame - frame objects see below for details
	https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#frame-object

See also: Module:Arguments on enWiki - which is much larger single purpose module
]]
function core.getArgs(frame)
	local function normalize_input_args(input_args, output_args)
		for name, value in pairs( input_args ) do 
			value = mw.text.trim(value) -- trim whitespaces from the beggining and the end of the string
			if value ~= '' then -- nuke empty strings
				if type(name)=='string' then 
					name = string.gsub( string.lower(name), ' ', '_')
				end
				output_args[name] = value
			end
		end
		return output_args
	end
	local args = {}
	args = normalize_input_args(frame:getParent().args, args)
	args = normalize_input_args(frame.args, args)
	if (args.lang and mw.language.isSupportedLanguage(args.lang)) then 
		args.lang = string.lower(args.lang)
	else
		args.lang = frame:callParserFunction("int","lang")  -- get user's chosen language
	end
	return args
end

------------------------------------------------------------------------------
--[[
Simplified code equivalent to https://commons.wikimedia.org/wiki/Template:LangSwitch

Example usage:
  text = langSwitch({en='text in english', pl='tekst po polsku'}, lang)

Inputs:
  1: args - table with translations by language
  2: lang - desired language (often user's native language)
  
Outputs:
  1: label - returned label
  2: lang  - language of the label (langSwitchWithLang only)
]]
function core.langSwitchWithLang(args, lang)
	local langList = mw.language.getFallbacksFor(lang)
	table.insert(langList,1,lang)
	for i,language in ipairs(langList) do
		if args[language] then
			return args[language], language
		end
	end
end

function core.langSwitch(args, lang)
	local label, lang = core.langSwitchWithLang(args, lang)
	return label
end

------------------------------------------------------------------------------
--[[
display a language followed by a message. Like "English: Hello" with extensive HTML marking
Code equivalent to https://commons.wikimedia.org/wiki/Template:Description 
Inputs:
  1) text_lang - language code for the above text, also used as a name of the CSS formating class
  2) text - description text to display
  3) args -  additional optional arguments. Numbers in perenthesis are parameter numbers in the original template.
	   * hover    - (3) hover aka mouseover aka tooltip text
	   * lang_tag - (4) standard code for lang tag in HTML (optional, default is same as text_lang)
	   * ext      - (5) extension text shown after the language name before colon (optional, default is empty)
       * inline - Optional, default is false. When set to true, forces the template to be displayed 
            inline, so that it does not break the current paragraph (that makes possible to put several 
	        descriptions side by side on a single line)	   
]]
function core.langWrapper(text_lang, text, args) 
	local dir, space, colon, lang_name, hover
	local inline    = core.yesno(args.inline, false) and 'inline' or nil 
	if 	mw.language.isKnownLanguageTag(text_lang) then -- supported language
		local langObj = mw.language.new( text_lang )
		dir       = langObj:getDir()          -- text direction
		space     = mw.message.new( "Word-separator" ):inLanguage(text_lang):plain() 
		colon     = mw.message.new( "Colon" ):inLanguage(text_lang):plain() 
		hover     = mw.language.fetchLanguageName( text_lang, args.user_lang or 'en')
		lang_name = mw.language.fetchLanguageName( text_lang, text_lang)
		lang_name = langObj:ucfirst(lang_name)
	else -- unsuported language
		local RTL_LUT = {['fa-af']=1, prd=1, ydd=1}
		dir   = (RTL_LUT[text_lang]==1 or text_lang:gsub('-arab', '')~=text_lang) and 'rtl' or 'ltr'
		space = ' '
		colon = ':'
		hover = args.hover
		lang_name = text_lang or 'Unknown'
	end
	lang_name = args.lang_name or lang_name-- user provided args.lang_name takes presedent
	lang_name = '<b>' .. lang_name .. (args.ext or '') .. colon .. '</b>'
	
	-- create HTML
	local ltag = mw.html.create('span')  -- bold language name string
		:addClass('language')  -- class: "language" 
		:addClass(text_lang)   -- class:  "en", "de" etc.	
		:attr('title', hover)  -- add hover aka mouseover aka tooltip text
		:wikitext(lang_name)
	local dtag = mw.html.create('div')
		:addClass('description')      -- div.description is tracked by mw:Extension:CommonsMetadata
		:addClass('mw-content-'..dir) -- mw-content-rtl and mw-content-ltr are defined in mediawiki-code (https://gerrit.wikimedia.org/r/c/mediawiki/core/+/208332)
		:addClass(text_lang)          -- not sure where "en", "de" etc. are defined
		:attr('dir', dir)
		:attr('lang', text_lang)
		:css('display', inline) 
		:wikitext(tostring(ltag) .. space .. text)
	return tostring(dtag)
end

------------------------------------------------------------------------------
--[[
Function allowing for consistent treatment of boolean-like wikitext input.
Inputs:
  1) val - value to be evaluated, outputs as a function of values:
		true  : true  (boolean), 1 (number), or strings: "yes", "y", "true", "1"
		false : false (boolean), 0 (number), or strings: "no", "n", "false", "0"
  2) default - value to return otherwise
See Also: It works similarly to Module:Yesno
]]
function core.yesno(val, default)
	if type(val) == 'boolean' then
		return val
	elseif type(val) == 'number' then
		val = tostring(val)
	end
	if type(val) == 'string' then
		local LUT = {
			yes=true , y=true , ['true'] =true , t=true , ['1']=true , on =true,
			no =false, n=false, ['false']=false, f=false, ['0']=false, off=false }
	    val = LUT[mw.ustring.lower(val)]  -- put in lower case
	    if (val~=nil) then
			return val
		end
    end
    return default
end

------------------------------------------------------------------------------
--[[
Read Commons Data:SOMENAME.tab dataset and look for message identified by a 
"key" in a language "lang". See editAtWikidata for an example. It uses
https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#mw.ext.data

Inputs:
 1) dataset - name of commons page in "data" namespace. for example "I18n/EditAt.tab" 
	for c:Data:I18n/EditAt.tab
 2) key - which message to pull
 3) lang - desired language of the message
Output: message as a string
]]
function core.formatMessage(dataset, key, lang)
	for _, row in pairs(mw.ext.data.get(dataset, lang).data) do
		local id, msg = unpack(row)
		if id == key then
			return mw.message.newRawMessage(msg):plain()
		end
	end
	error('Invalid message key "' .. key .. '"')
end

------------------------------------------------------------------------------
--[[
Assembles the "Edit at Wikidata" pen icon with a link to Wikidata page or specific 
property and returns it as wikitext string.
Inputs:
  1) entityID - wikidata entity object for a given page (output of wikibase.getEntity( id ))
  2) propertyID - string like 'P31' so the link will point to that specific property. Use "" 
     to link to the whole page. 
  3) lang - language of the "Edit at Wikidata"  message
Dependencies: Data:I18n/EditAt.tab
See Also: en:Module:EditAtWikidata
]]
-------------------------------------------------------------------------------
function core.editAtWikidata(entityID, propertyID, lang)
	local msg  = core.formatMessage('I18n/EditAt.tab', 'EditAtWikidata', lang)
	local link = 'https://www.wikidata.org/wiki/' .. entityID .. (propertyID == "" and "" or ("#" .. propertyID))
	return "&nbsp;[[File:OOjs UI icon edit-ltr-progressive.svg |frameless |text-top |10px |alt="..msg.."|link="..link.."|"..msg.."]]"
end

------------------------------------------------------------------------------
--[[
Assembles the "Edit at SDC" pen icon with a link to a property in SDC part of the current file 
page, and returns it as wikitext string.
Inputs:
  2) propertyID - string like 'P31' so the link will point to that specific property. Use 'ooui-php-4' 
     to link to the label section. 
  3) lang - language of the "Edit at Wikidata"  message
Dependencies: Data:I18n/EditAt.tab
See Also: en:Module:EditAtWikidata
]]
function core.editAtSDC(propertyID, lang)
	local msg  = core.formatMessage('I18n/EditAt.tab', 'EditAtSDC', lang)
	local link =  mw.title.getCurrentTitle():fullUrl() .. (propertyID == "" and "" or ("#" .. propertyID))
	return "&nbsp;[[File:OOjs UI icon edit-ltr-progressive.svg |frameless |text-top |10px |alt="..msg.."|link="..link.."|"..msg.."]]"
end

-------------------------------------------------------------------------------
--[[
This function returns a label translated to desired language, created based on wikidata
Code equivalent to require("Module:Wikidata label")._getLabel

Inputs:
	1: item - wikidata's item's q-id or entity class
	2: userLang - desired language of the label
]]
function core.getLabel(item, userLang) 
	local label, link
	-- build language fallback list
	local langList = mw.language.getFallbacksFor(userLang)
	table.insert(langList, 1, userLang) 
	-- get label
	for _, lang in ipairs(langList) do  -- loop over language fallback list looking for label in the specific language
		label = mw.wikibase.getLabelByLang(item, lang)
		if label then break end                    -- label found and we are done
	end	
	label = label or item -- fallback value
	-- get link
	for _, lang in ipairs(langList) do  -- loop over language fallback list looking for label in the specific language
		link =  mw.wikibase.getSitelink(item, lang .. 'wiki')
		if link then
			link = mw.ustring.format('w:%s:%s', lang, link)
			break
		end
	end
	link = link or 'd:'..item -- fallback value
	-- look for description
	local desc = mw.wikibase.getDescription(item)
	if desc then  -- add description if we have one
		desc  = mw.text.nowiki(desc) -- add description as hover text
		label = '<span title="' .. desc .. '">' .. label .. '</span>'
	end
   return '[['..link..'|'..label..']]'
end

-------------------------------------------------------------------------------
--[[
Core component of many "get property value" functions
Example: (core.parse_statements(entity:getBestStatements( prop ), nil) or {nil})[1] would 
return the first best statement
Inputs:
 1: statements - can be provided by:
   * entity:getBestStatements( prop )
   * entity:getAllStatements( prop )
   * mw.wikibase.getBestStatements( item, prop )
   * mw.wikibase.getAllStatements( item, prop )
 2: lang - language code (like "en"), if provided than item IDs will be 
     changed to a label
Output:
 * table of strings or nil
]]
function core.parseStatements(statements, lang)
	local output = {}
	for _, statement in ipairs(statements) do
		if (statement.mainsnak.snaktype == "value") and (statement.rank ~= 'deprecated')  then
			table.insert(output, core.parseSnak(statement.mainsnak, lang))
		end
	end
	if #output==0 then return nil end
	return output
end

-------------------------------------------------------------------------------
--[[
parse part of the statement called "snak"

Inputs:
 1: snak - 
 2: lang - language code (like "en"), if provided than item IDs will be 
     changed to a label
Output:
 * string
]]
function core.parseSnak(snak, lang)
	local val = snak.datavalue.value
	if val.id then 
		val = val.id
		if lang ~= nil then
			val = core.getLabel(val, lang)
		end
	elseif val.text then
		val = val.text
	elseif val.amount then
		val = tonumber(val.amount)
	elseif val.time then -- handle most dates (use [[Module:Wikidata date]]	for the rest
		local gregorian = 'http://www.wikidata.org/entity/Q1985727'
		if (val.calendarmodel==gregorian) and (mw.ustring.sub(val.time,1,1)=='+') and val.precision >= 9 then 
			local trim = 3*math.min(val.precision,11) - 22 -- day (11)->11, month (10)->8, year (9)->5
			val = mw.ustring.sub(val.time, 2, trim)    -- return YYYY-MM-DD, YYYY-MM or YYYY depending on precission
		end
	end
	return val
end

return core