close
Sayahna Sayahna
Search

Difference between revisions of "Module:Category handler"


m (1 revision)
(allow invocations specifying the page parameter to use the mw.loadData optimisations, and don't call mw.title.new every time)
Line 1: Line 1:
----------------------------------------------------------------------------------------------------------
+
--------------------------------------------------------------------------------
--                                                                                                     --
+
--                                                                           --
--                                         CATEGORY HANDLER                                           --
+
--                             CATEGORY HANDLER                             --
--                                                                                                     --
+
--                                                                           --
--      This module implements the {{category handler}} template in Lua, with a few improvements: all   --
+
--      This module implements the {{category handler}} template in Lua,     --
--      namespaces and all namespace aliases are supported, and namespace names are detected           --
+
--      with a few improvements: all namespaces and all namespace aliases    --
--      automatically for the local wiki. This module requires [[Module:Namespace detect]] and          --
+
--      are supported, and namespace names are detected automatically for    --
--      [[Module:Yesno]] to be available on the local wiki. It can be configured for different wikis    --
+
--      the local wiki. This module requires [[Module:Namespace detect]]     --
--      by altering the values in the "cfg" table.                                                      --
+
--      and [[Module:Yesno]] to be available on the local wiki. It can be     --
--                                                                                                     --
+
--      configured for different wikis by altering the values in             --
----------------------------------------------------------------------------------------------------------
+
--     [[Module:Category handler/config]], and pages can be blacklisted      --
 +
--     from categorisation by using [[Module:Category handler/blacklist]].  --
 +
--                                                                           --
 +
--------------------------------------------------------------------------------
  
----------------------------------------------------------------------------------------------------------
+
-- Load required modules
--                                          Configuration data                                          --
+
local yesno = require('Module:Yesno')
--                      Language-specific parameter names and values can be set here.                  --
 
----------------------------------------------------------------------------------------------------------
 
  
local cfg = {}
+
-- Lazily load things we don't always need
 +
local mShared, mappings
  
-- The following config values set the names of parameters that suppress categorisation. They are used
+
local p = {}
-- 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
+
-- Helper functions
-- 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
+
local function trimWhitespace(s, removeBlanks)
-- specify to not categorise on subpages; cfg.only is the value to specify to only categorise on subpages.
+
if type(s) ~= 'string' then
cfg.subpage = 'subpage'
+
return s
cfg.subpageNo = 'no'
+
end
cfg.subpageOnly = 'only'
+
s = s:match('^%s*(.-)%s*$')
 +
if removeBlanks then
 +
if s ~= '' then
 +
return s
 +
else
 +
return nil
 +
end
 +
else
 +
return s
 +
end
 +
end
  
-- The parameter for data to return in all namespaces.
+
--------------------------------------------------------------------------------
cfg.all = 'all'
+
-- CategoryHandler class
 +
--------------------------------------------------------------------------------
  
-- The parameter name for data to return if no data is specified for the namespace that is detected. This
+
local CategoryHandler = {}
-- must be the same as the cfg.other parameter in [[Module:Namespace detect]].
+
CategoryHandler.__index = CategoryHandler
cfg.other = 'other'
 
  
-- The parameter name used to specify a page other than the current page; used for testing and
+
function CategoryHandler.new(data, args)
-- demonstration. This must be the same as the cfg.page parameter in [[Module:Namespace detect]].
+
local obj = setmetatable({ _data = data, _args = args }, CategoryHandler)
cfg.page = 'page'
+
 +
-- Set the title object
 +
do
 +
local pagename = obj:parameter('demopage')
 +
local success, titleObj
 +
if pagename then
 +
success, titleObj = pcall(mw.title.new, pagename)
 +
end
 +
if success and titleObj then
 +
obj.title = titleObj
 +
if titleObj == mw.title.getCurrentTitle() then
 +
obj._usesCurrentTitle = true
 +
end
 +
else
 +
obj.title = mw.title.getCurrentTitle()
 +
obj._usesCurrentTitle = true
 +
end
 +
end
  
-- The categorisation blacklist. Pages that match Lua patterns in this list will not be categorised.
+
-- Set suppression parameter values
-- (However, see the explanation of cfg.nocat, cfg.categories and cfg.category2 for some exceptions.)
+
for _, key in ipairs{'nocat', 'categories'} do
-- If the namespace name has a space in, it must be written with an underscore, e.g. "Wikipedia_talk".
+
local value = obj:parameter(key)
-- Other parts of the title can have either underscores or spaces.
+
value = trimWhitespace(value, true)
cfg.blacklist = {
+
obj['_' .. key] = yesno(value)
    '^Main Page$', -- don't categorise the main page.
+
end
   
+
do
    -- Don't categorise the following pages or their subpages.
+
local subpage = obj:parameter('subpage')
    '^Wikipedia:Cascade%-protected items$',
+
local category2 = obj:parameter('category2')
    '^Wikipedia:Cascade%-protected items/.*$',
+
if type(subpage) == 'string' then
    '^User:UBX$', -- The userbox "template" space.
+
subpage = mw.ustring.lower(subpage)
    '^User:UBX/.*$',
+
end
    '^User_talk:UBX$',
+
if type(category2) == 'string' then
    '^User_talk:UBX/.*$',
+
subpage = mw.ustring.lower(category2)
   
+
end
    -- Don't categorise subpages of these pages, but allow
+
obj._subpage = trimWhitespace(subpage, true)
    -- categorisation of the base page.
+
obj._category2 = trimWhitespace(category2) -- don't remove blank values
    '^Wikipedia:Template messages/.+$',
+
end
   
+
return obj
    '/[aA]rchive' -- Don't categorise archives.
+
end
}
 
  
-- This is a table of namespaces to categorise by default. They should be in the format of parameter
+
function CategoryHandler:parameter(key)
-- names accepted by [[Module:Namespace detect]].
+
local parameterNames = self._data.parameters[key]
cfg.defaultNamespaces = {
+
local pntype = type(parameterNames)
    'main',
+
if pntype == 'string' or pntype == 'number' then
    'file',
+
return self._args[parameterNames]
    'help',
+
elseif pntype == 'table' then
    'category'
+
for _, name in ipairs(parameterNames) do
}
+
local value = self._args[name]
 +
if value ~= nil then
 +
return value
 +
end
 +
end
 +
return nil
 +
else
 +
error(string.format(
 +
'invalid config key "%s"',
 +
tostring(key)
 +
), 2)
 +
end
 +
end
  
----------------------------------------------------------------------------------------------------------
+
function CategoryHandler:isSuppressedByArguments()
--                                          End configuration data                                      --
+
return
----------------------------------------------------------------------------------------------------------
+
-- See if a category suppression argument has been set.
 +
self._nocat == true
 +
or self._categories == false
 +
or (
 +
self._category2
 +
and self._category2 ~= self._data.category2Yes
 +
and self._category2 ~= self._data.category2Negative
 +
)
  
-- Get dependent modules
+
-- Check whether we are on a subpage, and see if categories are
local nsDetect = require('Module:Namespace detect')
+
-- suppressed based on our subpage status.
local yesno = require('Module:Yesno')
+
or self._subpage == self._data.subpageNo and self.title.isSubpage
 +
or self._subpage == self._data.subpageOnly and not self.title.isSubpage
 +
end
 +
 
 +
function CategoryHandler:shouldSkipBlacklistCheck()
 +
-- Check whether the category suppression arguments indicate we
 +
-- should skip the blacklist check.
 +
return self._nocat == false
 +
or self._categories == true
 +
or self._category2 == self._data.category2Yes
 +
end
 +
 
 +
function CategoryHandler:matchesBlacklist()
 +
if self._usesCurrentTitle then
 +
return self._data.currentTitleMatchesBlacklist
 +
else
 +
mShared = mShared or require('Module:Category handler/shared')
 +
return mShared.matchesBlacklist(
 +
self.title.prefixedText,
 +
mw.loadData('Module:Category handler/blacklist')
 +
)
 +
end
 +
end
  
----------------------------------------------------------------------------------------------------------
+
function CategoryHandler:isSuppressed()
--                                          Local functions                                            --
+
-- Find if categories are suppressed by either the arguments or by
--      The following are internal functions, which we do not want to be accessible from other modules. --
+
-- matching the blacklist.
----------------------------------------------------------------------------------------------------------
+
return self:isSuppressedByArguments()
 +
or not self:shouldSkipBlacklistCheck() and self:matchesBlacklist()
 +
end
  
-- Find whether we need to return a category or not.
+
function CategoryHandler:getNamespaceParameters()
local function needsCategory(pageObject, args)
+
if self._usesCurrentTitle then
    -- Don't categorise if the relevant options are set.
+
return self._data.currentTitleNamespaceParameters
    if yesno(args[cfg.nocat])
+
else
        or yesno(args[cfg.categories]) == false
+
if not mappings then
        or (
+
mShared = mShared or require('Module:Category handler/shared')
            args[cfg.category2]
+
mappings = mShared.getParamMappings(true) -- gets mappings with mw.loadData
            and args[cfg.category2] ~= cfg.category2Yes
+
end
            and args[cfg.category2] ~= cfg.category2Negative
+
return mShared.getNamespaceParameters(
        )
+
self.title,
    then
+
mappings
        return false
+
)
    end
+
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
 
end
  
-- Find whether we need to check the blacklist or not.
+
function CategoryHandler:namespaceParametersExist()
local function needsBlacklistCheck(args)
+
-- Find whether any namespace parameters have been specified.
    if yesno(args[cfg.nocat]) == false
+
-- We use the order "all" --> namespace params --> "other" as this is what
        or yesno(args[cfg.categories]) == true
+
-- the old template did.
        or args[cfg.category2] == cfg.category2Yes
+
if self:parameter('all') then
    then
+
return true
        return false
+
end
    else
+
if not mappings then
        return true
+
mShared = mShared or require('Module:Category handler/shared')
    end
+
mappings = mShared.getParamMappings(true) -- gets mappings with mw.loadData
 +
end
 +
for ns, params in pairs(mappings) do
 +
for i, param in ipairs(params) do
 +
if self._args[param] then
 +
return true
 +
end
 +
end
 +
end
 +
if self:parameter('other') then
 +
return true
 +
end
 +
return false
 
end
 
end
  
-- Find whether any namespace parameters have been specified.
+
function CategoryHandler:getCategories()
-- Mappings is the table of parameter mappings taken from
+
local params = self:getNamespaceParameters()
-- [[Module:Namespace detect]].
+
local nsCategory
local function nsParamsExist(mappings, args)
+
for i, param in ipairs(params) do
    if args[cfg.all] or args[cfg.other] then
+
local value = self._args[param]
        return true
+
if value ~= nil then
    end
+
nsCategory = value
    for ns, params in pairs(mappings) do
+
break
        for i, param in ipairs(params) do
+
end
            if args[param] then
+
end
                return true
+
if nsCategory ~= nil or self:namespaceParametersExist() then
            end
+
-- Namespace parameters exist - advanced usage.
        end
+
if nsCategory == nil then
    end
+
nsCategory = self:parameter('other')
    return false
+
end
 +
local ret = {self:parameter('all')}
 +
local numParam = tonumber(nsCategory)
 +
if numParam and numParam >= 1 and math.floor(numParam) == numParam then
 +
-- nsCategory is an integer
 +
ret[#ret + 1] = self._args[numParam]
 +
else
 +
ret[#ret + 1] = nsCategory
 +
end
 +
if #ret < 1 then
 +
return nil
 +
else
 +
return table.concat(ret)
 +
end
 +
elseif self._data.defaultNamespaces[self.title.namespace] then
 +
-- Namespace parameters don't exist, simple usage.
 +
return self._args[1]
 +
end
 +
return nil
 
end
 
end
  
----------------------------------------------------------------------------------------------------------
+
--------------------------------------------------------------------------------
--                                          Global functions                                            --
+
-- Exports
--      The following functions are global, because we want them to be accessible from #invoke and      --
+
--------------------------------------------------------------------------------
--     from other Lua modules.                                                                        --
 
----------------------------------------------------------------------------------------------------------
 
  
 
local p = {}
 
local p = {}
  
-- Find if a string matches the blacklist. Returns the match if one is found, or nil otherwise.
+
function p._exportClasses()
-- Input should be a page title with a namespace prefix, e.g. "Wikipedia talk:Articles for deletion".
+
-- Used for testing purposes.
function p.matchesBlacklist(page)
+
return {
    if type(page) ~= 'string' then return end
+
CategoryHandler = CategoryHandler
    for i, pattern in ipairs(cfg.blacklist) do
+
}
        local match = mw.ustring.match(page, pattern)
 
        if match then
 
            return match
 
        end
 
    end
 
 
end
 
end
  
-- The main structure of the module. Checks whether we need to categorise,
+
function p._main(args, data)
-- and then passes the relevant arguments to [[Module:Namespace detect]].
+
data = data or mw.loadData('Module:Category handler/data')
function p._main(args)
+
local handler = CategoryHandler.new(data, args)
    -- Get the page object and argument mappings from
+
if handler:isSuppressed() then
    -- [[Module:Namespace detect]], to save us from having to rewrite the
+
return nil
    -- code.
+
end
    local pageObject = nsDetect.getPageObject(args[cfg.page])
+
return handler:getCategories()
    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
 
end
  
function p.main(frame)
+
function p.main(frame, data)
    -- If called via #invoke, use the args passed into the invoking
+
data = data or mw.loadData('Module:Category handler/data')
    -- template, or the args passed to #invoke if any exist. Otherwise
+
local args = require('Module:Arguments').getArgs(frame, {
    -- assume args are being passed directly in.
+
wrappers = data.wrappers,
    local origArgs
+
valueFunc = function (k, v)
    if frame == mw.getCurrentFrame() then
+
v = trimWhitespace(v)
        origArgs = frame:getParent().args
+
if type(k) == 'number' then
        for k, v in pairs(frame.args) do
+
if v ~= '' then
            origArgs = frame.args
+
return v
            break
+
else
        end
+
return nil
    else
+
end
        origArgs = frame
+
else
    end
+
return v
 
+
end
    -- Trim whitespace and remove blank arguments for the following args:
+
end
    -- 1, 2, 3 etc., "nocat", "categories", "subpage", and "page".
+
})
    local args = {}
+
return p._main(args, data)
    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
 
end
  
 
return p
 
return p

Revision as of 05:08, 22 July 2014

Documentation for this module may be created at Module:Category handler/doc

--------------------------------------------------------------------------------
--                                                                            --
--                              CATEGORY HANDLER                              --
--                                                                            --
--      This module implements the {{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              --
--      [[Module:Category handler/config]], and pages can be blacklisted      --
--      from categorisation by using [[Module:Category handler/blacklist]].   --
--                                                                            --
--------------------------------------------------------------------------------

-- Load required modules
local yesno = require('Module:Yesno')

-- Lazily load things we don't always need
local mShared, mappings

local p = {}

--------------------------------------------------------------------------------
-- Helper functions
--------------------------------------------------------------------------------

local function trimWhitespace(s, removeBlanks)
	if type(s) ~= 'string' then
		return s
	end
	s = s:match('^%s*(.-)%s*$')
	if removeBlanks then
		if s ~= '' then
			return s
		else
			return nil
		end
	else
		return s
	end
end

--------------------------------------------------------------------------------
-- CategoryHandler class
--------------------------------------------------------------------------------

local CategoryHandler = {}
CategoryHandler.__index = CategoryHandler

function CategoryHandler.new(data, args)
	local obj = setmetatable({ _data = data, _args = args }, CategoryHandler)
	
	-- Set the title object
	do
		local pagename = obj:parameter('demopage')
		local success, titleObj
		if pagename then
			success, titleObj = pcall(mw.title.new, pagename)
		end
		if success and titleObj then
			obj.title = titleObj
			if titleObj == mw.title.getCurrentTitle() then
				obj._usesCurrentTitle = true
			end
		else
			obj.title = mw.title.getCurrentTitle()
			obj._usesCurrentTitle = true
		end
	end

	-- Set suppression parameter values
	for _, key in ipairs{'nocat', 'categories'} do
		local value = obj:parameter(key)
		value = trimWhitespace(value, true)
		obj['_' .. key] = yesno(value)
	end
	do
		local subpage = obj:parameter('subpage')
		local category2 = obj:parameter('category2')
		if type(subpage) == 'string' then
			subpage = mw.ustring.lower(subpage)
		end
		if type(category2) == 'string' then
			subpage = mw.ustring.lower(category2)
		end
		obj._subpage = trimWhitespace(subpage, true)
		obj._category2 = trimWhitespace(category2) -- don't remove blank values
	end
	return obj
end

function CategoryHandler:parameter(key)
	local parameterNames = self._data.parameters[key]
	local pntype = type(parameterNames)
	if pntype == 'string' or pntype == 'number' then
		return self._args[parameterNames]
	elseif pntype == 'table' then
		for _, name in ipairs(parameterNames) do
			local value = self._args[name]
			if value ~= nil then
				return value
			end
		end
		return nil
	else
		error(string.format(
			'invalid config key "%s"',
			tostring(key)
		), 2)
	end
end

function CategoryHandler:isSuppressedByArguments()
	return
		-- See if a category suppression argument has been set.
		self._nocat == true
		or self._categories == false
		or (
			self._category2
			and self._category2 ~= self._data.category2Yes
			and self._category2 ~= self._data.category2Negative
		)

		-- Check whether we are on a subpage, and see if categories are
		-- suppressed based on our subpage status.
		or self._subpage == self._data.subpageNo and self.title.isSubpage
		or self._subpage == self._data.subpageOnly and not self.title.isSubpage
end

function CategoryHandler:shouldSkipBlacklistCheck()
	-- Check whether the category suppression arguments indicate we
	-- should skip the blacklist check.
	return self._nocat == false
		or self._categories == true
		or self._category2 == self._data.category2Yes
end

function CategoryHandler:matchesBlacklist()
	if self._usesCurrentTitle then
		return self._data.currentTitleMatchesBlacklist
	else
		mShared = mShared or require('Module:Category handler/shared')
		return mShared.matchesBlacklist(
			self.title.prefixedText,
			mw.loadData('Module:Category handler/blacklist')
		)
	end
end

function CategoryHandler:isSuppressed()
	-- Find if categories are suppressed by either the arguments or by
	-- matching the blacklist.
	return self:isSuppressedByArguments()
		or not self:shouldSkipBlacklistCheck() and self:matchesBlacklist()
end

function CategoryHandler:getNamespaceParameters()
	if self._usesCurrentTitle then
		return self._data.currentTitleNamespaceParameters
	else
		if not mappings then
			mShared = mShared or require('Module:Category handler/shared')
			mappings = mShared.getParamMappings(true) -- gets mappings with mw.loadData
		end
		return mShared.getNamespaceParameters(
			self.title,
			mappings
		)
	end
end

function CategoryHandler:namespaceParametersExist()
	-- Find whether any namespace parameters have been specified.
	-- We use the order "all" --> namespace params --> "other" as this is what
	-- the old template did.
	if self:parameter('all') then
		return true
	end
	if not mappings then
		mShared = mShared or require('Module:Category handler/shared')
		mappings = mShared.getParamMappings(true) -- gets mappings with mw.loadData
	end
	for ns, params in pairs(mappings) do
		for i, param in ipairs(params) do
			if self._args[param] then
				return true
			end
		end
	end
	if self:parameter('other') then
		return true
	end
	return false
end

function CategoryHandler:getCategories()
	local params = self:getNamespaceParameters()
	local nsCategory
	for i, param in ipairs(params) do
		local value = self._args[param]
		if value ~= nil then
			nsCategory = value
			break
		end
	end
	if nsCategory ~= nil or self:namespaceParametersExist() then
		-- Namespace parameters exist - advanced usage.
		if nsCategory == nil then
			nsCategory = self:parameter('other')
		end
		local ret = {self:parameter('all')}
		local numParam = tonumber(nsCategory)
		if numParam and numParam >= 1 and math.floor(numParam) == numParam then
			-- nsCategory is an integer
			ret[#ret + 1] = self._args[numParam]
		else
			ret[#ret + 1] = nsCategory
		end
		if #ret < 1 then
			return nil
		else
			return table.concat(ret)
		end
	elseif self._data.defaultNamespaces[self.title.namespace] then
		-- Namespace parameters don't exist, simple usage.
		return self._args[1]
	end
	return nil
end

--------------------------------------------------------------------------------
-- Exports
--------------------------------------------------------------------------------

local p = {}

function p._exportClasses()
	-- Used for testing purposes.
	return {
		CategoryHandler = CategoryHandler
	}
end

function p._main(args, data)
	data = data or mw.loadData('Module:Category handler/data')
	local handler = CategoryHandler.new(data, args)
	if handler:isSuppressed() then
		return nil
	end
	return handler:getCategories()
end

function p.main(frame, data)
	data = data or mw.loadData('Module:Category handler/data')
	local args = require('Module:Arguments').getArgs(frame, {
		wrappers = data.wrappers,
		valueFunc = function (k, v)
			v = trimWhitespace(v)
			if type(k) == 'number' then
				if v ~= '' then
					return v
				else
					return nil
				end
			else
				return v
			end
		end
	})
	return p._main(args, data)
end

return p