Module:Namespace detect

This module allows you to output different text depending on the namespace that a given page is in. It is a Lua implementation of the {{namespace detect}} template, with a few improvements: all namespaces and all namespace aliases are supported, and namespace names are detected automatically for the local wiki.

Usage

{{#invoke: Namespace detect | main
| page              = <!-- page to detect namespace for, if not the current page -->
| main              = <!-- text to return for the main namespace -->
| talk              = <!-- text to return for talk namespaces -->

<!-- text to return for specific subject namespaces -->
| portal            = 
| category          = 
| user 	            = 
| wikipedia         = 
| mediawiki         = 
| book              = 
| timedtext         = 
| template          = 
| special           = 
| media             = 
| file              = 
| image             = 
| help 	            = 
| module            = 

| other             = <!-- text to return for unspecified namespaces -->
| demospace         = <!-- namespace to display text for -->

| subjectns         = <!-- set to "yes" to treat talk pages as the corresponding subject page -->
}}

Parameters

• main - text to return if the page is in the main namespace.
• talk - text to return if the page is in a talk namespace. This can be any talk namespace - it will match any of "Talk:", "Wikipedia talk:", "User talk:", etc.
• Subject namespace parameters, e.g. wikipedia, user, file... - the text to return if the page is in the corresponding namespace. This module accepts all subject namespaces as parameters, including namespace aliases and virtual namespaces. See below for a list of supported values.
• other - text to return if no parameters for the page's namespace were specified. This text is also returned if Template:Para is set to an invalid namespace value.
• subjectns - if on a talk page, use the corresponding subject page. Can be set with values of "yes", "y", "true" or "1".
• demopage - specifies a page to detect the namespace of. If not specified, and if the Template:Para parameter is not set, then the module uses the current page.
• demospace - force the module to behave as if the page was in the specified namespace. Often used for demonstrations.

Namespace parameters

Possible values for subject namespace parameters are as follows:

Namespace	Aliases
main
user
mywikibiz	project
file	image
mediawiki
template
help
category
portal
directory
property
concept
smw/schema
rule
geojson
module

Table function

Use the following to display a table with the different possible namespace parameters:

{{#invoke:Namespace detect|table|talk=yes}}

To include the parameter for talk namespaces, use Template:Para.

Porting to different wikis

This module is designed to be portable. To use it on a different wiki, all you need to do is to change the values in Module:Namespace detect/config. Instructions are available on that page.

Technical details

The module uses a data page at Module:Namespace detect/data. This page is loaded with mw.loadData, which means it is processed once per page rather than once per #invoke. This was done for performance reasons.

---

--[[
--------------------------------------------------------------------------------
--                                                                            --
--                            NAMESPACE DETECT                                --
--                                                                            --
-- This module implements the {{namespace detect}} 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. The     --
-- module can also use the corresponding subject namespace value if it is     --
-- used on a talk page. Parameter names can be configured for different wikis --
-- by altering the values in the "cfg" table in                               --
-- Module:Namespace detect/config.                                            --
--                                                                            --
--------------------------------------------------------------------------------
--]]

local data = mw.loadData('Module:Namespace detect/data')
local argKeys = data.argKeys
local cfg = data.cfg
local mappings = data.mappings

local yesno = require('Module:Yesno')
local mArguments -- Lazily initialise Module:Arguments
local mTableTools -- Lazily initilalise Module:TableTools
local ustringLower = mw.ustring.lower

local p = {}

local function fetchValue(t1, t2)
	-- Fetches a value from the table t1 for the first key in array t2 where
	-- a non-nil value of t1 exists.
	for i, key in ipairs(t2) do
		local value = t1[key]
		if value ~= nil then
			return value
		end
	end
	return nil
end

local function equalsArrayValue(t, value)
	-- Returns true if value equals a value in the array t. Otherwise
	-- returns false.
	for i, arrayValue in ipairs(t) do
		if value == arrayValue then
			return true
		end
	end
	return false
end

function p.getPageObject(page)
	-- Get the page object, passing the function through pcall in case of
	-- errors, e.g. being over the expensive function count limit.
	if page then
		local success, pageObject = pcall(mw.title.new, page)
		if success then
			return pageObject
		else
			return nil
		end
	else
		return mw.title.getCurrentTitle()
	end
end

-- Provided for backward compatibility with other modules
function p.getParamMappings()
	return mappings
end

local function getNamespace(args)
	-- This function gets the namespace name from the page object.
	local page = fetchValue(args, argKeys.demopage)
	if page == '' then
		page = nil
	end
	local demospace = fetchValue(args, argKeys.demospace)
	if demospace == '' then
		demospace = nil
	end
	local subjectns = fetchValue(args, argKeys.subjectns)
	local ret
	if demospace then
		-- Handle "demospace = main" properly.
		if equalsArrayValue(argKeys.main, ustringLower(demospace)) then
			ret = mw.site.namespaces[0].name
		else
			ret = demospace
		end
	else
		local pageObject = p.getPageObject(page)
		if pageObject then
			if pageObject.isTalkPage then
				-- Get the subject namespace if the option is set,
				-- otherwise use "talk".
				if yesno(subjectns) then
					ret = mw.site.namespaces[pageObject.namespace].subject.name
				else
					ret = 'talk'
				end
			else
				ret = pageObject.nsText
			end
		else
			return nil -- return nil if the page object doesn't exist.
		end
	end
	ret = ret:gsub('_', ' ')
	return ustringLower(ret)
end

function p._main(args)
	-- Check the parameters stored in the mappings table for any matches.
	local namespace = getNamespace(args) or 'other' -- "other" avoids nil table keys
	local params = mappings[namespace] or {}
	local ret = fetchValue(args, params)
	--[[
	-- If there were no matches, return parameters for other namespaces.
	-- This happens if there was no text specified for the namespace that
	-- was detected or if the demospace parameter is not a valid
	-- namespace. Note that the parameter for the detected namespace must be
	-- completely absent for this to happen, not merely blank.
	--]]
	if ret == nil then
		ret = fetchValue(args, argKeys.other)
	end
	return ret
end

function p.main(frame)
	mArguments = require('Module:Arguments')
	local args = mArguments.getArgs(frame, {removeBlanks = false})
	local ret = p._main(args)
	return ret or ''
end

function p.table(frame)
	--[[
	-- Create a wikitable of all subject namespace parameters, for
	-- documentation purposes. The talk parameter is optional, in case it
	-- needs to be excluded in the documentation.
	--]]
	
	-- Load modules and initialise variables.
	mTableTools = require('Module:TableTools')
	local namespaces = mw.site.namespaces
	local cfg = data.cfg
	local useTalk = type(frame) == 'table' 
		and type(frame.args) == 'table' 
		and yesno(frame.args.talk) -- Whether to use the talk parameter.
	
	-- Get the header names.
	local function checkValue(value, default)
		if type(value) == 'string' then
			return value
		else
			return default
		end
	end
	local nsHeader = checkValue(cfg.wikitableNamespaceHeader, 'Namespace')
	local aliasesHeader = checkValue(cfg.wikitableAliasesHeader, 'Aliases')

	-- Put the namespaces in order.
	local mappingsOrdered = {}
	for nsname, params in pairs(mappings) do
		if useTalk or nsname ~= 'talk' then
			local nsid = namespaces[nsname].id
			-- Add 1, as the array must start with 1; nsid 0 would be lost otherwise.
			nsid = nsid + 1 
			mappingsOrdered[nsid] = params
		end
	end
	mappingsOrdered = mTableTools.compressSparseArray(mappingsOrdered)

	-- Build the table.
	local ret = '{| class="wikitable"'
		.. '\n|-'
		.. '\n! ' .. nsHeader
		.. '\n! ' .. aliasesHeader
	for i, params in ipairs(mappingsOrdered) do
		for j, param in ipairs(params) do
			if j == 1 then
				ret = ret .. '\n|-'
					.. '\n| <code>' .. param .. '</code>'
					.. '\n| '
			elseif j == 2 then
				ret = ret .. '<code>' .. param .. '</code>'
			else
				ret = ret .. ', <code>' .. param .. '</code>'
			end
		end
	end
	ret = ret .. '\n|-'
		.. '\n|}'
	return ret
end

return p