Category handler

---

-- -- -- CATEGORY HANDLER -- -- -- -- This module implements the Template:Category handler template in Lua, with a few improvements: all -- -- namespaces and all namespace aliases are supported, and namespace names are detected -- -- automatically for the local wiki. This module requires Module:Namespace detect and -- -- Module:Yesno to be available on the local wiki. It can be configured for different wikis -- -- by altering the values in the "cfg" table. -- -- --

---

---

-- Configuration data -- -- Language-specific parameter names and values can be set here. --

---

local cfg = {}

-- The following config values set the names of parameters that suppress categorisation. They are used -- with Module:Yesno, and work as follows: -- -- cfg.nocat: -- Result of yesno(args[cfg.nocat]) Effect -- true Categorisation is suppressed -- false Categorisation is allowed, and the blacklist check is skipped -- nil Categorisation is allowed -- -- cfg.categories: -- Result of yesno(args[cfg.categories]) Effect -- true Categorisation is allowed, and the blacklist check is skipped -- false Categorisation is suppressed -- nil Categorisation is allowed cfg.nocat = 'nocat' cfg.categories = 'categories'

-- The parameter name for the legacy "category2" parameter. This skips the blacklist if set to the -- cfg.category2Yes value, and suppresses categorisation if present but equal to anything other than -- cfg.category2Yes or cfg.category2Negative. cfg.category2 = 'category2' cfg.category2Yes = 'yes' cfg.category2Negative = '¬'

-- cfg.subpage is the parameter name to specify how to behave on subpages. cfg.subpageNo is the value to -- specify to not categorise on subpages; cfg.only is the value to specify to only categorise on subpages. cfg.subpage = 'subpage' cfg.subpageNo = 'no' cfg.subpageOnly = 'only'

-- The parameter for data to return in all namespaces. cfg.all = 'all'

-- The parameter name for data to return if no data is specified for the namespace that is detected. This -- must be the same as the cfg.other parameter in Module:Namespace detect. cfg.other = 'other'

-- The parameter name used to specify a page other than the current page; used for testing and -- demonstration. This must be the same as the cfg.page parameter in Module:Namespace detect. cfg.page = 'page'

-- The categorisation blacklist. Pages that match Lua patterns in this list will not be categorised. -- (However, see the explanation of cfg.nocat, cfg.categories and cfg.category2 for some exceptions.) -- If the namespace name has a space in, it must be written with an underscore, e.g. "Wikipedia_talk". -- Other parts of the title can have either underscores or spaces. cfg.blacklist = {

   '^Main Page$', -- don't categorise the main page.
   
   -- Don't categorise the following pages or their subpages.
   '^Wikipedia:Cascade%-protected items$',
   '^Wikipedia:Cascade%-protected items/.*$',
   '^User:UBX$', -- The userbox "template" space.
   '^User:UBX/.*$',
   '^User_talk:UBX$',
   '^User_talk:UBX/.*$',
   
   -- Don't categorise subpages of these pages, but allow
   -- categorisation of the base page.
   '^Wikipedia:Template messages/.+$',
   
   '/[aA]rchive' -- Don't categorise archives.

}

-- This is a table of namespaces to categorise by default. They should be in the format of parameter -- names accepted by Module:Namespace detect. cfg.defaultNamespaces = {

   'main',
   'file',
   'help',
   'category'

}

---

-- End configuration data --

---

-- Get dependent modules local nsDetect = require('Module:Namespace detect') local yesno = require('Module:Yesno')

---

-- Local functions -- -- The following are internal functions, which we do not want to be accessible from other modules. --

---

-- Find whether we need to return a category or not. local function needsCategory(pageObject, args)

   -- Don't categorise if the relevant options are set.
   if yesno(args[cfg.nocat])
       or yesno(args[cfg.categories]) == false
       or (
           args[cfg.category2] 
           and args[cfg.category2] ~= cfg.category2Yes 
           and args[cfg.category2] ~= cfg.category2Negative
       )
   then
       return false
   end
   -- If there is no pageObject available, then that either means that we are over
   -- the expensive function limit or that the title specified was invalid. Invalid
   -- titles will probably only be a problem during testing, so we choose the best
   -- fallback for being over the expensive function limit. The fallback behaviour
   -- of the old template was to assume the page was not a subpage, so we will do
   -- the same here.
   if args[cfg.subpage] == cfg.subpageNo and pageObject and pageObject.isSubpage then
       return false
   end
   if args[cfg.subpage] == cfg.subpageOnly 
       and (not pageObject or (pageObject and not pageObject.isSubpage))
   then
       return false
   end
   return true

end

-- Find whether we need to check the blacklist or not. local function needsBlacklistCheck(args)

   if yesno(args[cfg.nocat]) == false
       or yesno(args[cfg.categories]) == true
       or args[cfg.category2] == cfg.category2Yes
   then
       return false
   else
       return true
   end

end

-- Find whether any namespace parameters have been specified. -- Mappings is the table of parameter mappings taken from -- Module:Namespace detect. local function nsParamsExist(mappings, args)

   if args[cfg.all] or args[cfg.other] then
       return true
   end
   for ns, params in pairs(mappings) do
       for i, param in ipairs(params) do
           if args[param] then
               return true
           end
       end
   end
   return false

end

---

-- Global functions -- -- The following functions are global, because we want them to be accessible from #invoke and -- -- from other Lua modules. --

---

local p = {}

-- Find if a string matches the blacklist. Returns the match if one is found, or nil otherwise. -- Input should be a page title with a namespace prefix, e.g. "Wikipedia talk:Articles for deletion". function p.matchesBlacklist(page)

   if type(page) ~= 'string' then return end
   for i, pattern in ipairs(cfg.blacklist) do
       local match = mw.ustring.match(page, pattern)
       if match then
           return match
       end
   end

end

-- The main structure of the module. Checks whether we need to categorise, -- and then passes the relevant arguments to Module:Namespace detect. function p._main(args)

   -- Get the page object and argument mappings from
   -- Module:Namespace detect, to save us from having to rewrite the
   -- code.
   local pageObject = nsDetect.getPageObject(args[cfg.page])
   local mappings = nsDetect.getParamMappings()
   
   if not needsCategory(pageObject, args) then return end
   
   local ret = 
   -- Check blacklist if necessary.
   if not needsBlacklistCheck(args) or not p.matchesBlacklist(pageObject.prefixedText) then
       if not nsParamsExist(mappings, args) then
           -- No namespace parameters exist; basic usage. Pass args[1] to
           -- Module:Namespace detect using the default namespace
           -- parameters, and return the result.
           local ndargs = {}
           for _, ndarg in ipairs(cfg.defaultNamespaces) do
               ndargs[ndarg] = args[1]
           end
           ndargs.page = args.page
           ndargs.demospace = args.demospace
           local ndresult = nsDetect._main(ndargs)
           if ndresult then
               ret = ret .. ndresult
           end
       else
           -- Namespace parameters exist; advanced usage.
           -- If the all parameter is specified, return it.
           local all = args.all
           if type(all) == 'string' then
               ret = ret .. all
           end
           
           -- Get the arguments to pass to Module:Namespace detect.
           local ndargs = {}
           for ns, params in pairs(mappings) do
               for _, param in ipairs(params) do
                   ndargs[param] = args[param] or args[cfg.other] or nil
               end
           end
           ndargs.other = args.other
           ndargs.page = args.page
           ndargs.demospace = args.demospace
           
           local data = nsDetect._main(ndargs)
           
           -- Work out what to return based on the result of the namespace detect call.
           local datanum = tonumber(data)
           if type(datanum) == 'number' then
               -- "data" is a number, so return that positional parameter.
               -- Remove non-positive integer values, as only positive integers
               -- from 1-10 were used with the old template.
               if datanum > 0 and math.floor(datanum) == datanum then
                   local dataArg = args[datanum]
                   if type(dataArg) == 'string' then
                       ret = ret .. dataArg
                   end
               end
           else
               -- "data" is not a number, so return it as it is.
               if type(data) == 'string' then
                   ret = ret .. data
               end
           end
       end
   end
   return ret

end

function p.main(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.
   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 for the following args:
   -- 1, 2, 3 etc., "nocat", "categories", "subpage", and "page".
   local args = {}
   for k, v in pairs(origArgs) do
       if type(v) == 'string' then
           v = mw.text.trim(v) -- Trim whitespace.
       end
       if type(k) == 'number'
           or k == cfg.nocat
           or k == cfg.categories
           or k == cfg.subpage
           or k == cfg.page
       then
           if v ~=  then
               args[k] = v
           end
       else
           args[k] = v
       end
   end
   
   -- Lower-case "nocat", "categories", "category2", and "subpage". These
   -- parameters are put in lower case whenever they appear in the old
   -- template, so we can just do it once here and save ourselves some work.
   local lowercase = {cfg.nocat, cfg.categories, cfg.category2, cfg.subpage}
   for _, v in ipairs(lowercase) do
       local argVal = args[v]
       if type(argVal) == 'string' then
           args[v] = mw.ustring.lower(argVal)
       end
   end
   
   return p._main(args)

end

return p