Module:Namespace detect

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    Revision as of 09:43, 16 November 2019 by Ondo (talk | contribs) (2 revisions imported from templatewiki:Module:Namespace_detect)
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    Documentation for this module may be created at Module:Namespace detect/doc

    --[[
    --------------------------------------------------------------------------------
    --                                                                            --
    --                            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