Documentation for this module may be created at మాడ్యూల్:Pagetype/doc

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--                                                                                                --
--                                           PAGETYPE                                             --
--                                                                                                --
--      This is a meta-module intended to replace {{pagetype}} and similar templates. It          --
--      automatically detects namespaces, and allows for a great deal of customisation.           --
--      It can easily be ported to other wikis by changing the values in the configuration        --
--      table.
--                                                                                                --
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local cfg = {}

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--                                          Configuration data                                    --
--      This module can be localised for other wikis by using the configuration parameters below. --
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-- This table holds the values to use for "main=true", "user=true", etc. Keys to this table should
-- be namespace parameters that can be used with [[Module:Namespace detect]]. 
cfg.pagetypes = {
	['main']              = 'article',
	['user']              = 'user page',
	['project']           = 'project page',
	['wikipedia']         = 'project page',
	['wp']                = 'project page',
	['file']              = 'file',
	['image']             = 'file',
	['mediawiki']         = 'interface page',
	['template']          = 'template',
	['help']              = 'help page',
	['category']          = 'category',
	['portal']            = 'portal',
	['book']              = 'book',
	['education program'] = 'education program page',
	['timedtext']         = 'Timed Text page',
	['module']            = 'module',
	['talk']              = 'talk page',
	['special']           = 'special page',
	['media']             = 'file'
}

-- This table holds the names of the namespaces to be looked up from cfg.pagetypes by default.
cfg.defaultNamespaces = {'main', 'file', 'template', 'category', 'module', 'book'}

-- This table holds the names of the namespaces to be looked up from cry.pagetypes if cfg.defaultnsExtended is set.
cfg.extendedNamespaces = {'main', 'user', 'project', 'file', 'mediawiki', 'template', 'category', 'help', 'portal', 'module', 'book'}

-- The parameter name to set which default namespace values to be looked up from cfg.pagetypes.
cfg.defaultns = 'defaultns'

-- The value of cfg.defaultns to set all namespaces, including talk.
cfg.defaultnsAll = 'all'

-- The value of cfg.defaultns to set the namespaces listed in cfg.extendedNamespaces
cfg.defaultnsExtended = 'extended'

-- The value of cfg.defaultns to set no default namespaces.
cfg.defaultnsNone = 'none'

-- The parameter name to use for disambiguation pages page.
cfg.dab = 'dab'

-- This table holds the different possible aliases for disambiguation-class pages. These should be lower-case.
cfg.dabAliases = {'disambiguation', 'disambig', 'disamb', 'dab'}

-- The default value for disambiguation pages.
cfg.dabDefault = 'page'

-- The parameter name to use for N/A-class page.
cfg.na = 'na'

-- This table holds the different possible aliases for N/A-class pages. These should be lower-case.
cfg.naAliases = {'na', 'n/a'}

-- The default value for N/A-class pages.
cfg.naDefault = 'page'

-- The parameter name to use for redirects.
cfg.redirect = 'redirect'

-- The default value to use for redirects.
cfg.redirectDefault = 'redirect'

-- The parameter name for undefined namespaces.
cfg.other = 'other'

-- The value used if the module detects an undefined namespace.
cfg.otherDefault = 'page'

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--                                       End configuration data                                   --
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-- Load required modules.
local yesno = require('Module:Yesno')
local nsDetectModule = require('Module:Namespace detect')
local nsDetect = nsDetectModule._main
local getParamMappings = nsDetectModule.getParamMappings
local getPageObject = nsDetectModule.getPageObject

local p = {}

local function checkPagetypeInput(namespace, val)
	-- Checks to see whether we need the default value for the given namespace, and if so gets it from the pagetypes table.
	local ret = yesno(val, val) -- Returns true/false for "yes", "no", etc., and returns val for other input.
	if ret and type(ret) ~= 'string' then
		ret = cfg.pagetypes[namespace]
	end
	return ret
end

local function getPagetypeFromClass(class, param, aliasTable, default)
	-- Gets the pagetype from a class specified from the first positional parameter.
	param = yesno(param, param)
	if param ~= false then -- Check for classes unless they are specifically disallowed.
		for _, alias in ipairs(aliasTable) do
			if class == alias then
				if type(param) == 'string' then
					return param
				else
					return default
				end
			end
		end
	end
end

local function getNsDetectValue(args)
	-- Builds the arguments to pass to [[Module:Namespace detect]] and returns the result.
	-- First, get the default values.
	local ndArgs = {}
	local defaultns = args[cfg.defaultns]
	if defaultns == cfg.defaultnsAll then
		ndArgs = cfg.pagetypes
	else
		local defaultnsArray
		if defaultns == cfg.defaultnsExtended then
			defaultnsArray = cfg.extendedNamespaces
		elseif defaultns == cfg.defaultnsNone then
			defaultnsArray = {}
		else
			defaultnsArray = cfg.defaultNamespaces
		end
		for _, namespace in ipairs(defaultnsArray) do
			ndArgs[namespace] = cfg.pagetypes[namespace]
		end
	end
	-- Add custom values passed in from the arguments. These overwrite the defaults.
	-- The possible argument names are fetched from [[Module:Namespace detect]] automatically in case new namespaces are added.
	-- Although we accept namespace aliases as parameters, we only pass the local namespace name as a parameter to [[Module:Namespace detect]].
	-- This means that the "image" parameter can overwrite defaults for the File: namespace, which wouldn't work if we passed the parameters through separately.
	local mappings = getParamMappings()
	for ns, paramAliases in pairs(mappings) do
		local paramName = paramAliases[1] 
		for i = #paramAliases, 1, -1 do -- Iterate backwards along the array so that any values for the local namespace names overwrite those for namespace aliases.
			local paramAlias = paramAliases[i]
			local ndArg = checkPagetypeInput(paramAlias, args[paramAlias])
			if ndArg == false then
				-- If any arguments are false, convert them to nil to protect against breakage by future changes to [[Module:Namespace detect]].
				ndArgs[paramName] = nil
			elseif ndArg then
				ndArgs[paramName] = ndArg
			end
		end
	end
	-- Check for disambiguation-class and N/A-class pages in mainspace.
	if ndArgs.main then
		local class = args[1]
		if type(class) == 'string' then
			-- Put in lower case so e.g. "Dab" and "dab" will both match.
			class = mw.ustring.lower(class)
		end
		local dab = getPagetypeFromClass(class, args[cfg.dab], cfg.dabAliases, cfg.dabDefault)
		if dab then
			ndArgs.main = dab
		else
			local na = getPagetypeFromClass(class, args[cfg.na], cfg.naAliases, cfg.naDefault)
			if na then
				ndArgs.main = na
			end
		end
	end
	-- If there is no talk value specified, use the corresponding subject namespace for talk pages.
	if not ndArgs.talk then
		ndArgs.subjectns = true
	end
	-- Add the fallback value. This can also be customised, but it cannot be disabled.
	local other = args[cfg.other]
	other = yesno(other, other) -- We will ignore true/false/nil results from yesno here, but using it anyway for consistency.
	if type(other) == 'string' then
		ndArgs.other = other
	else
		ndArgs.other = cfg.otherDefault
	end
	-- Allow custom page values.
	ndArgs.page = args.page
	return nsDetect(ndArgs)
end

local function detectRedirects(args)
	local redirect = args[cfg.redirect]
	redirect = yesno(redirect, redirect) -- Returns true/false for "yes", "no", etc., and returns redirect for other input.
	if redirect == false then return end -- Detect redirects unless they have been explicitly disallowed with "redirect=no" or similar.
	local pageObject = getPageObject(args.page)
	-- If we are using subject namespaces elsewhere, do so here as well.
	if pageObject and not yesno(args.talk, true) then
		pageObject = getPageObject(pageObject.subjectNsText .. ':' .. pageObject.text)
	end
	-- Allow custom values for redirects.
	if pageObject and pageObject.isRedirect then
		if type(redirect) == 'string' then
			return redirect
		else
			return cfg.redirectDefault
		end
	end
end

function p._main(args)
	local redirect = detectRedirects(args)
	if redirect then
		return redirect
	else
		return getNsDetectValue(args)
	end
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 from the debug console or from another Lua module.
	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.
	local args = {}
	for k, v in pairs(origArgs) do
		if type(v) == 'string' then
			v = mw.text.trim(v)
		end
		if v ~= '' then
			args[k] = v
		end
	end
	return p._main(args)
end

return p