Editing Module:WikiProjectBanner/Context

-------------------------------------------------------------------------------
--                               Context class                               --
-- This module contains the Context class used in Module:WikiProjectBanner.  --
-- It stores data about the title we are being called from, provides access  --
-- to the config and banner config modules, generates data commonly used by  --
-- subclasses (e.g. project name), and provides a place to store data        --
-- generated by subclasses that needs to be reused (e.g. Grade objects)      --
-------------------------------------------------------------------------------

-- Load required modules
local mShared = require('Module:WikiProjectBanner/shared')
local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType

-- Lazily load modules we don't always need.
local yesno

local Context = {}

function Context.new(bannerName, args, cfg, bannerCfg)
	local obj = {}

	-- Check the input set default values.
	checkType('Context.new', 1, project, 'string')
	checkType('Context.new', 2, args, 'table', true)
	checkType('Context.new', 3, cfg, 'table', true)
	checkType('Context.new', 4, bannerCfg, 'table', true)
	obj.bannerName = bannerName
	obj.args = args or {}
	obj.cfg = cfg or mw.loadData('Module:WikiProjectBanner/config')
	obj.bannerCfg = bannerCfg or mShared.maybeRequire(
		'Module:WikiProjectBanner/banners/' .. data.bannerName
	)
	if not obj.bannerCfg then
		error(
			'banner data page [[Module:WikiProjectBanner/banners/' ..
			bannerName ..
			']] does not exist',
			0
		)
	end

	-- Set properties that we will need every time or that are inexpensive.
	obj.currentTitle = mw.title.getCurrentTitle()
	obj.subjectTitle = obj.currentTitle.subjectPageTitle

	-- Set up the metatable and define functions for properties to be
	-- generated on the fly. These functions are used for properties that are
	-- expensive to generate and that we might not need.
	local propertyFuncs = {}
	setmetatable(obj, {
		__index = function (t, key)
			local func = propertyFuncs[key]
			if func then
				local val = func()
				obj[key] = val
				return val
			else
				return Context[key]
			end			
		end
	})

	function propertyFuncs.pageType()
		return require('Module:Pagetype')._main{}
	end

	function propertyFuncs.project()
		-- Gets the project name from the banner name.
		-- For example, for "WikiProject Tulips", the project name would be
		-- "Tulips".
		if obj.bannerCfg.project then
			return obj.bannerData.project
		else
			local pattern = obj.cfg.msg['project-page-name-pattern']
			return mw.ustring.match(obj.bannerName, pattern) or obj.bannerName
		end
	end

	function propertyFuncs.projectLink()
		-- The project page, e.g. "Wikipedia:WikiProject Tulips".
		if obj.bannerCfg.projectLink then
			return obj.bannerCfg.projectLink
		else
			local msg = obj.cfg.msg['project-link']
			return mShared.substituteParams(msg, obj.project)
		end
	end

	function propertyFuncs.projectName()
		-- The project name without a namespace prefix,
		-- e.g. "WikiProject Tulips".
		if obj.bannerCfg.projectName then
			return obj.bannerCfg.projectName
		else
			local msg = obj.cfg.msg['project-name']
			return mShared.substituteParams(msg, obj.project)
		end
	end

	function propertyFuncs.projectScope()
		-- A link to an article that encapsulates the project's scope,
		-- e.g. "[[Tulips]]". The link will have square brackets added if they
		-- are not already present.
		local scope = obj.bannerCfg.projectScope
		if scope and scope:find('^%[%[') then
			return scope
		elseif scope then
			return mShared.makeWikilink(scope)
		else
			return mShared.makeWikilink(obj.project)
		end
	end

	function propertyFuncs.projectLinkTalk()
		-- A link to the project talk page, without square brackets, e.g.
		-- "Wikipedia talk:WikiProject Tulips".
		return mw.title.new(obj.projectLink).talkPageTitle.prefixedText
	end

	function propertyFuncs.assessmentLink()
		-- The page containing the project's assessment scales.
		if obj.bannerCfg.assessmentLink ~= nil then
			-- Custom link or false for no link
			return bannerCfg.assessmentLink
		else
			local assessmentPage = obj.projectLink .. '/Assessment'
			local assessmentTitle = mw.title.new(assessmentPage)
			return assessmentTitle
				and assessmentTitle.exists
				and assessmentTitle.prefixedText
				or false
		end
	end

	function propertyFuncs.isSmall()
		-- Whether we are outputting a small banner or not.
		yesno = yesno or require('Module:Yesno')
		return yesno(obj.args.small)
	end
	
	function propertyFuncs.isDemo()
		-- Whether we are outputting a demo page.
		local currentPage = obj.currentTitle.prefixedText
		local template = mw.site.namespaces[10].name .. ':' .. obj.bannerName
		local sandboxSubpage = obj.cfg.msg['sandbox-subpage']
		return currentPage == template
			or currentPage == template .. '/' .. sandboxSubpage
	end

	return obj
end

return Context