Editing Module:Template translation

local this = {}

function this.checkLanguage(subpage, default)
    --[[Check first if there's an any invalid character that would cause the
        mw.language.isKnownLanguageTag function() to throw an exception:
        - all ASCII controls in [\000-\031\127],
        - double quote ("), sharp sign (#), ampersand (&), apostrophe ('),
        - slash (/), colon (:), semicolon (;), lower than (<), greater than (>),
        - brackets and braces ([, ], {, }), pipe (|), backslash (\\)
        All other characters are accepted, including space and all non-ASCII
        characters (including \192, which is invalid in UTF-8).
    --]]
    if mw.language.isValidCode(subpage) and mw.language.isKnownLanguageTag(subpage)
    --[[However "SupportedLanguages" are too restrictive, as they discard many
        valid BCP47 script variants (only because MediaWiki still does not
        define automatic transliterators for them, e.g. "en-dsrt" or
        "fr-brai" for French transliteration in Braille), and country variants,
        (useful in localized data, even if they are no longer used for
        translations, such as zh-cn, also useful for legacy codes).
        We want to avoid matching subpagenames containing any uppercase letter,
        (even if they are considered valid in BCP 47, in which they are
        case-insensitive; they are not "SupportedLanguages" for MediaWiki, so
        they are not "KnownLanguageTags" for MediaWiki).
        To be more restrictive, we exclude any character
        * that is not ASCII and not a lowercase letter, minus-hyphen, or digit,
          or does not start by a letter or does not finish by a letter or digit;
        * or that has more than 8 characters between hyphens;
        * or that has two hyphens;
        * or with specific uses in template subpages and unusable as languages.
    --]]
    or  string.find(subpage, "^[%l][%-%d%l]*[%d%l]$") ~= nil
    and string.find(subpage, "[%d%l][%d%l][%d%l][%d%l][%d%l][%d%l][%d%l][%d%l][%d%l]") == nil
    and string.find(subpage, "%-%-") == nil
    and subpage ~= "doc"
    and subpage ~= "layout"
    and subpage ~= "sandbox"
    and subpage ~= "testcases"
    then
        return subpage
    end
    -- Otherwise there's currently no known language subpage
    return default
end

--[[Get the last subpage of the current page if it is a translation.
    ]]
function this.getLanguageSubpage()
	--[[This code does not work in all namespaces where the Translate tool works.
	--  It works in the main namespace on Meta because it allows subpages there
	--  It would not work in the main namespace of English Wikipedia (but the
	--  articles are monolignual on that wiki).
	--  On Meta-Wiki the main space uses subpages and its pages are translated.
	--  The Translate tool allows translatng pages in all namespaces, even if
	--  the namespace officially does not have subpages.
	--  On Meta-Wiki the Category namespace still does not have subpages enabled,
	--  even if they would be very useful for categorizing templates, that DO have
	--  subpages (for documentatio and tstboxes pages). This is a misconfiguration
	--  bug of Meta-Wiki. The work-around is to split the full title and then
	--  get the last titlepart.
	local subpage = mw.title.getCurrentTitle().subpageText
	--]]
    local titleparts = mw.text.split(mw.title.getCurrentTitle().fullText, '/')
    local subpage = titleparts[#titleparts]
    return this.checkLanguage(subpage, '')
end

--[[Get the first part of the language code of the subpage, before the '-'.
    ]]
function this.getMainLanguageSubpage()
	parts = mw.text.split( this.getLanguageSubpage(), '-' )
	return parts[1]
end

--[[Get the last subpage of the current frame if it is a translation.
    Not used locally.
    ]]
function this.getFrameLanguageSubpage(frame)
    local titleparts = mw.text.split(frame:getParent():getTitle(), '/')
    local subpage = titleparts[#titleparts]
    return this.checkLanguage(subpage, '')
end

--[[Get the language of the current page.
    Not used locally.
    ]]
function this.getLanguage()
    local subpage = mw.title.getCurrentTitle().subpageText
    return this.checkLanguage(subpage, mw.language.getContentLanguage():getCode())
end

--[[Get the language of the current frame.
    Not used locally.
    ]]
function this.getFrameLanguage(frame)
    local titleparts = mw.text.split(frame:getParent():getTitle(), '/')
    local subpage = titleparts[#titleparts]
    return this.checkLanguage(subpage, mw.language.getContentLanguage():getCode())
end

function this.title(namespace, basepagename, subpage)
    local message, title
    local pagename = basepagename
    if (subpage or '') ~= ''
    then
        pagename = pagename .. '/' .. subpage
    end
    local valid, title = xpcall(function()
            return mw.title.new(pagename, namespace) -- costly
        end, function(msg) -- catch undocumented exception (!?)
            -- thrown when namespace does not exist. The doc still
            -- says it should return a title, even in that case...
            message = msg
        end)
    if valid and title ~= nil and (title.id or 0) ~= 0
    then
        return title
    end
    return { -- "pseudo" mw.title object with id = nil in case of error
        prefixedText = pagename, -- the only property we need below
        message = message -- only for debugging
    }
end

--[[If on a translation subpage (like Foobar/de), this function returns
    a given template in the same language, if the translation is available.
    Otherwise, the template is returned in its default language, without
    modification.
    This is aimed at replacing the current implementation of Template:TNTN.

    This version does not expand the returned template name: this solves the
    problem of self-recursion in TNT when translatable templates need themselves
    to transclude other translable templates (such as Tnavbar).
    ]]
function this.getTranslatedTemplate(frame, withStatus)
    local args = frame.args
    local pagename = args['template']
    
    --[[Check whether the pagename is actually in the Template namespace, or
        if we're transcluding a main-namespace page.
        (added for backward compatibility of Template:TNT)
        ]]
    local title
    local namespace = args['tntns'] or ''
    if (namespace ~= '') -- Checks for tntns parameter for custom ns.
    then
        title = this.title(namespace, pagename) -- Costly
    else -- Supposes that set page is in ns10.
    	namespace = 'Template'
        title = this.title(namespace, pagename) -- Costly
        if title.id == nil
        then -- not found in the Template namespace, assume the main namespace (for backward compatibility)
    	    namespace = ''
            title = this.title(namespace, pagename) -- Costly
        end
    end
    
    -- Get the last subpage and check if it matches a known language code.
    local subpage = args['uselang'] or ''
    if (subpage == '')
    then
        subpage = this.getLanguageSubpage()
    end
    if (subpage == '')
    then
        -- Check if a translation of the pagename exists in English
        local newtitle = this.title(namespace, pagename, 'en') -- Costly
        -- Use the translation when it exists
        if newtitle.id ~= nil
        then
            title = newtitle
        end
    else
        -- Check if a translation of the pagename exists in that language
        local newtitle = this.title(namespace, pagename, subpage) -- Costly
        if newtitle.id == nil
        then
            -- Check if a translation of the pagename exists in English
            newtitle = this.title(namespace, pagename, 'en') -- Costly
        end
        -- Use the translation when it exists
        if newtitle.id ~= nil
        then
            title = newtitle
        end
    end
    -- At this point the title should exist
    if withStatus then
    	-- status returned to Lua function below
        return title.prefixedText, title.id ~= nil
    else
    	-- returned directly to MediaWiki
        return title.prefixedText
    end
end

--[[If on a translation subpage (like Foobar/de), this function renders
    a given template in the same language, if the translation is available.
    Otherwise, the template is rendered in its default language, without
    modification.
    This is aimed at replacing the current implementation of Template:TNT.
    
    Note that translatable templates cannot transclude themselves other
    translatable templates, as it will recurse on TNT. Use TNTN instead
    to return only the effective template name to expand externally, with
    template parameters also provided externally.
    ]]
function this.renderTranslatedTemplate(frame)
	local title, found = this.getTranslatedTemplate(frame, true)
    -- At this point the title should exist prior to performing the expansion
    -- of the template, otherwise render a red link to the missing page
    -- (resolved in its assumed namespace). If we don't tet this here, a
    -- script error would be thrown. Returning a red link is consistant with
    -- MediaWiki behavior when attempting to transclude inexistant templates.
	if not found then
		return '[[' .. title .. ']]'
	end

    -- Copy args pseudo-table to a proper table so we can feed it to expandTemplate.
    -- Then render the pagename.
    local args = frame.args
    local pargs = (frame:getParent() or {}).args
    local arguments = {}
    if (args['noshift'] or '') == ''
    then
        for k, v in pairs(pargs) do
            -- numbered args >= 1 need to be shifted
            local n = tonumber(k) or 0
            if (n > 0)
            then
                if (n >= 2)
                then
                    arguments[n - 1] = v
                end
            else
                arguments[k] = v
            end
        end
    else -- special case where TNT is used as autotranslate
    	-- (don't shift again what is shifted in the invokation)
        for k, v in pairs(pargs) do
            arguments[k] = v
        end
    end
    arguments['template'] = title -- override the existing parameter of the base template name supplied with the full name of the actual template expanded
    arguments['tntns'] = nil -- discard the specified namespace override
    arguments['uselang'] = args['uselang'] -- argument forwarded into parent frame
    arguments['noshift'] = args['noshift'] -- argument forwarded into parent frame
    
    return frame:expandTemplate{title = ':' .. title, args = arguments}
end

--[[A helper for mocking TNT in Special:TemplateSandbox. TNT breaks
    TemplateSandbox; mocking it with this method means templates won't be
    localized but at least TemplateSandbox substitutions will work properly.
    Won't work with complex uses.
    ]]
function this.mockTNT(frame)
    local pargs = (frame:getParent() or {}).args
    local arguments = {}
    for k, v in pairs(pargs) do
        -- numbered args >= 1 need to be shifted
        local n = tonumber(k) or 0
        if (n > 0)
        then
            if (n >= 2)
            then
                arguments[n - 1] = v
            end
        else
            arguments[k] = v
        end
    end
    if not pargs[1]
    then
    	return ''
	end
    return frame:expandTemplate{title = 'Template:' .. pargs[1], args = arguments}
end

return this
@@ Line 22: / Line 22: @@
          case-insensitive; they are not "SupportedLanguages" for MediaWiki, so
          they are not "KnownLanguageTags" for MediaWiki).
-         To be more restrictive, we exclude tags
+         To be more restrictive, we exclude any character
-        * for specific uses in template subpages and unusable as language tags;
          * that is not ASCII and not a lowercase letter, minus-hyphen, or digit,
            or does not start by a letter or does not finish by a letter or digit;
-         * or that has subtags with more than 8 characters between hyphens;
+         * or that has more than 8 characters between hyphens;
-         * or that has two hyphens.
+         * or that has two hyphens;
+        * or with specific uses in template subpages and unusable as languages.
      --]]
-     or  subpage ~= "doc"
+     or  string.find(subpage, "^[%l][%-%d%l]*[%d%l]$") ~= nil
+    and string.find(subpage, "[%d%l][%d%l][%d%l][%d%l][%d%l][%d%l][%d%l][%d%l][%d%l]") == nil
+    and string.find(subpage, "%-%-") == nil
+    and subpage ~= "doc"
      and subpage ~= "layout"
-    and subpage ~= "button"
-    and subpage ~= "buttons"
      and subpage ~= "sandbox"
-    and subpage ~= "testcase"
      and subpage ~= "testcases"
-     and string.find(subpage, "^[%l][%-%d%l]*[%d%l]$") ~= nil
+     then
-    and string.find(subpage, "[%d%l][%d%l][%d%l][%d%l][%d%l][%d%l][%d%l][%d%l][%d%l]") == nil
-    and string.find(subpage, "%-%-") == nil then
          return subpage
      end
@@ Line 45: / Line 43: @@
 end
---[[Get the last subpage of an arbitrary page if it is a translation.
+--[[Get the last subpage of the current page if it is a translation.
-    To be used from templates.
-    ]]
-function this.getLanguageSubpage(frame)
-	local title = frame and frame.args[1]
-	if not title or title == '' then
-		title = mw.title.getCurrentTitle()
-	end
-	return this._getLanguageSubpage(title)
-end
---[[Get the last subpage of an arbitrary page if it is a translation.
-    To be used from Lua.
      ]]
-function this._getLanguageSubpage(title)
+function this.getLanguageSubpage()
-	if type(title) == 'string' then
-		title = mw.title.new(title)
-	end
-	if not title then
-		-- invalid title
-		return nil
-	end
 	--[[This code does not work in all namespaces where the Translate tool works.
 	--  It works in the main namespace on Meta because it allows subpages there
@@ Line 79: / Line 58: @@
 	--  bug of Meta-Wiki. The work-around is to split the full title and then
 	--  get the last titlepart.
-	local subpage = title.subpageText
+	local subpage = mw.title.getCurrentTitle().subpageText
 	--]]
-	local titleparts = mw.text.split(title.fullText, '/')
+    local titleparts = mw.text.split(mw.title.getCurrentTitle().fullText, '/')
-	local subpage = titleparts[#titleparts]
+    local subpage = titleparts[#titleparts]
-	return this.checkLanguage(subpage, '')
+    return this.checkLanguage(subpage, '')
 end
---[[Get the last subpage of the current page if it is a translation.
+--[[Get the first part of the language code of the subpage, before the '-'.
      ]]
-function this.getCurrentLanguageSubpage()
-	return this._getLanguageSubpage(mw.title.getCurrentTitle())
-end
---[[Get the first part of the language code of the subpage, before the '-'.
---]]
 function this.getMainLanguageSubpage()
-	parts = mw.text.split(this.getCurrentLanguageSubpage(), '-')
+	parts = mw.text.split( this.getLanguageSubpage(), '-' )
 	return parts[1]
 end
@@ Line 101: / Line 74: @@
 --[[Get the last subpage of the current frame if it is a translation.
      Not used locally.
---]]
+    ]]
 function this.getFrameLanguageSubpage(frame)
-	return this._getLanguageSubpage(frame:getParent():getTitle())
+    local titleparts = mw.text.split(frame:getParent():getTitle(), '/')
+    local subpage = titleparts[#titleparts]
+    return this.checkLanguage(subpage, '')
 end
---[[Get the language of the current page. Not used locally.
+--[[Get the language of the current page.
---]]
+    Not used locally.
+    ]]
 function this.getLanguage()
      local subpage = mw.title.getCurrentTitle().subpageText
@@ Line 113: / Line 89: @@
 end
---[[Get the language of the current frame. Not used locally.
+--[[Get the language of the current frame.
---]]
+    Not used locally.
+    ]]
 function this.getFrameLanguage(frame)
      local titleparts = mw.text.split(frame:getParent():getTitle(), '/')
@@ Line 124: / Line 101: @@
      local message, title
      local pagename = basepagename
-     if (subpage or '') ~= '' then
+     if (subpage or '') ~= ''
+    then
          pagename = pagename .. '/' .. subpage
      end
@@ Line 134: / Line 112: @@
              message = msg
          end)
-     if valid and title ~= nil and (title.id or 0) ~= 0 then
+     if valid and title ~= nil and (title.id or 0) ~= 0
+    then
          return title
      end
@@ Line 152: / Line 131: @@
      problem of self-recursion in TNT when translatable templates need themselves
      to transclude other translable templates (such as Tnavbar).
---]]
+    ]]
 function this.getTranslatedTemplate(frame, withStatus)
      local args = frame.args
      local pagename = args['template']
      --[[Check whether the pagename is actually in the Template namespace, or
          if we're transcluding a main-namespace page.
          (added for backward compatibility of Template:TNT)
          ]]
-     local namespace, title = args['tntns'] or ''
+    local title
-     if namespace ~= '' then -- Checks for tntns parameter for custom ns.
+     local namespace = args['tntns'] or ''
+     if (namespace ~= '') -- Checks for tntns parameter for custom ns.
+    then
          title = this.title(namespace, pagename) -- Costly
      else -- Supposes that set page is in ns10.
      	namespace = 'Template'
          title = this.title(namespace, pagename) -- Costly
-         if title.id == nil then -- not found in the Template namespace, assume the main namespace (for backward compatibility)
+         if title.id == nil
+        then -- not found in the Template namespace, assume the main namespace (for backward compatibility)
      	    namespace = ''
              title = this.title(namespace, pagename) -- Costly
          end
      end
      -- Get the last subpage and check if it matches a known language code.
      local subpage = args['uselang'] or ''
-     if subpage == '' then
+     if (subpage == '')
-         subpage = this.getCurrentLanguageSubpage()
+    then
+         subpage = this.getLanguageSubpage()
      end
-     if subpage == '' then
+     if (subpage == '')
+    then
          -- Check if a translation of the pagename exists in English
          local newtitle = this.title(namespace, pagename, 'en') -- Costly
          -- Use the translation when it exists
-         if newtitle.id ~= nil then
+         if newtitle.id ~= nil
+        then
              title = newtitle
          end
@@ Line 186: / Line 173: @@
          -- Check if a translation of the pagename exists in that language
          local newtitle = this.title(namespace, pagename, subpage) -- Costly
-         if newtitle.id == nil then
+         if newtitle.id == nil
+        then
              -- Check if a translation of the pagename exists in English
              newtitle = this.title(namespace, pagename, 'en') -- Costly
          end
          -- Use the translation when it exists
-         if newtitle.id ~= nil then
+         if newtitle.id ~= nil
+        then
              title = newtitle
          end
@@ Line 215: / Line 204: @@
      to return only the effective template name to expand externally, with
      template parameters also provided externally.
---]]
+    ]]
 function this.renderTranslatedTemplate(frame)
 	local title, found = this.getTranslatedTemplate(frame, true)
@@ Line 226: / Line 215: @@
 		return '[[' .. title .. ']]'
 	end
      -- Copy args pseudo-table to a proper table so we can feed it to expandTemplate.
      -- Then render the pagename.
@@ Line 231: / Line 221: @@
      local pargs = (frame:getParent() or {}).args
      local arguments = {}
-     if (args['noshift'] or '') == '' then
+     if (args['noshift'] or '') == ''
+    then
          for k, v in pairs(pargs) do
+            -- numbered args >= 1 need to be shifted
              local n = tonumber(k) or 0
-             if n <= 0 then -- unnumbered args
+             if (n > 0)
+            then
+                if (n >= 2)
+                then
+                    arguments[n - 1] = v
+                end
+            else
                  arguments[k] = v
-            elseif n >= 2 then -- numbered args >= 2 need to be shifted
-                arguments[n - 1] = v
              end
          end
@@ Line 250: / Line 246: @@
      arguments['uselang'] = args['uselang'] -- argument forwarded into parent frame
      arguments['noshift'] = args['noshift'] -- argument forwarded into parent frame
      return frame:expandTemplate{title = ':' .. title, args = arguments}
 end
@@ Line 257: / Line 254: @@
      localized but at least TemplateSandbox substitutions will work properly.
      Won't work with complex uses.
---]]
+    ]]
 function this.mockTNT(frame)
      local pargs = (frame:getParent() or {}).args
      local arguments = {}
      for k, v in pairs(pargs) do
+        -- numbered args >= 1 need to be shifted
          local n = tonumber(k) or 0
-         if n <= 0 then -- unnumbered args
+         if (n > 0)
+        then
+            if (n >= 2)
+            then
+                arguments[n - 1] = v
+            end
+        else
              arguments[k] = v
-        elseif n >= 2 then -- numbered args >= 2 need to be shifted
-            arguments[n - 1] = v
          end
      end
-     if not pargs[1] then
+     if not pargs[1]
+    then
      	return ''
 	end