Module:Arguments: Difference between revisions

    From Nonbinary Wiki
    m>Mr. Stradivarius
    (check fargs and pargs before writing new values to args if options.noOverwrite is set)
    m>Mr. Stradivarius
    (use an array to hold argument tables rather than firstArgs and secondArgs variables)
    Line 8: Line 8:


    -- Get the arguments from the frame object if available. If the frame object is not available, we are being called
    -- Get the arguments from the frame object if available. If the frame object is not available, we are being called
    -- from another Lua module or from the debug console, so assume arguments are passed directly in.
    -- from another Lua module or from the debug console, so put the args in a special table so we can differentiate them.
    local fargs, pargs
    local fargs, pargs, luaArgs
    if frame == mw.getCurrentFrame() then
    if frame == mw.getCurrentFrame() then
    fargs = frame.args
    fargs = frame.args
    pargs = frame:getParent().args
    pargs = frame:getParent().args
    else
    else
    fargs = type(frame) == 'table' and frame or {}
    luaArgs = type(frame) == 'table' and frame or {}
    pargs = {}
    end
    end


    -- Set up the args and metaArgs tables. args will be the one accessed from functions, and metaArgs will hold the actual arguments.
    -- The metatable connects the two together.
    local args, metaArgs, metatable = {}, {}, {}
    local args, metaArgs, metatable = {}, {}, {}
    setmetatable(args, metatable)
    setmetatable(args, metatable)
    Line 36: Line 37:
    end
    end


    -- Use a user-generated functions to tidy the values if specified.
    -- Use a user-generated function to tidy the values if specified.
    local valueFunc = options.valueFunc
    local valueFunc = options.valueFunc
    if valueFunc then
    if valueFunc then
    Line 47: Line 48:
    end
    end


    local function mergeArgs(iterator, ...)
    local function mergeArgs(iterator, tables)
    -- Accepts multiple tables as input and merges their keys and values into one table using the specified iterator.
    -- Accepts multiple tables as input and merges their keys and values into one table using the specified iterator.
    -- If a value is already present it is not overwritten; tables listed earlier have precendence.
    -- If a value is already present it is not overwritten; tables listed earlier have precendence.
    local tables = {...}
    for _, t in ipairs(tables) do
    for _, t in ipairs(tables) do
    for key, val in iterator(t) do
    for key, val in iterator(t) do
    Line 60: Line 60:
    end
    end


    -- Set the order of precedence of frame args and parent args.
    -- Set the order of precedence of the argument tables. If the variables are nil, nothing will be added to the table,
    local firstArgs, secondArgs = fargs, pargs
    -- which is how we avoid clashes between the frame/parent args and the Lua args.
    local argTables = {}
    if options.parentFirst then
    if options.parentFirst then
    firstArgs, secondArgs = pargs, fargs
    table.insert(argTables, pargs)
    table.insert(argTables, fargs)
    else
    table.insert(argTables, fargs)
    table.insert(argTables, pargs)
    end
    end
    table.insert(argTables, luaArgs)


    --[[
    --[[
    -- Define metatable behaviour. Arguments are stored in the metaArgs table, and are only fetched from the
    -- Define metatable behaviour. Arguments are stored in the metaArgs table, and are only fetched from the
    -- fargs and pargs tables once. Also, we keep a record in the metatable of when pairs and ipairs have
    -- argument tables once. Also, we keep a record in the metatable of when pairs and ipairs have been called,
    -- been called, so we do not run pairs and ipairs on fargs and pargs more than once. We also do not run
    -- so we do not run pairs and ipairs on fargs and pargs more than once. We also do not run ipairs on fargs
    -- ipairs on fargs and pargs if pairs has already been run, as all the arguments will already have been
    -- and pargs if pairs has already been run, as all the arguments will already have been copied over.
    -- copied over.
    --]]
    --]]
    metatable.__index = function (t, key)
    metatable.__index = function (t, key)
    Line 78: Line 83:
    return val
    return val
    else
    else
    local firstVal = tidyVal(key, firstArgs[key])
    for i, argTable in ipairs(argTables) do
    if firstVal ~= nil then
    local argTableVal = tidyVal(argTable[key])
    return firstVal
    if argTableVal ~= nil then
    else
    metaArgs[key] = argTableVal
    return tidyVal(key, secondArgs[key])
    return argTableVal
    end
    end
    end
    end
    end
    Line 95: Line 101:
    metatable.__pairs = function ()
    metatable.__pairs = function ()
    if not metatable.donePairs then
    if not metatable.donePairs then
    mergeArgs(pairs, firstArgs, secondArgs)
    mergeArgs(pairs, argTables)
    metatable.donePairs = true
    metatable.donePairs = true
    metatable.doneIpairs = true
    metatable.doneIpairs = true
    Line 104: Line 110:
    metatable.__ipairs = function ()
    metatable.__ipairs = function ()
    if not metatable.doneIpairs then
    if not metatable.doneIpairs then
    mergeArgs(ipairs, firstArgs, secondArgs)
    mergeArgs(ipairs, argTables)
    metatable.doneIpairs = true
    metatable.doneIpairs = true
    end
    end

    Revision as of 12:03, 9 December 2013

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

    -- This module provides easy processing of arguments passed to Scribunto from #invoke.
    -- It is intended for use by other Lua modules, and should not be called from #invoke directly.
    
    local arguments = {}
    
    function arguments.getArgs(frame, options)
    	options = type(options) == 'table' and options or {}
    
    	-- Get the arguments from the frame object if available. If the frame object is not available, we are being called
    	-- from another Lua module or from the debug console, so put the args in a special table so we can differentiate them.
    	local fargs, pargs, luaArgs
    	if frame == mw.getCurrentFrame() then
    		fargs = frame.args
    		pargs = frame:getParent().args
    	else
    		luaArgs = type(frame) == 'table' and frame or {}
    	end
    
    	-- Set up the args and metaArgs tables. args will be the one accessed from functions, and metaArgs will hold the actual arguments.
    	-- The metatable connects the two together.
    	local args, metaArgs, metatable = {}, {}, {}
    	setmetatable(args, metatable)
    
    	local function tidyVal(key, val)
    		-- Processes a value according to the options given to getArguments. Can trim whitespace and remove blanks.
    		-- Keys are not used here, but they can be used by user-generated functions, so defining it here to avoid breakage.
    		if type(val) == 'string' then
    			if options.trim ~= false then
    				val = mw.text.trim(val)
    			end
    			if options.removeBlanks == false or mw.ustring.find(val, '%S') then
    				return val
    			end
    		else
    			return val
    		end
    	end
    
    	-- Use a user-generated function to tidy the values if specified.
    	local valueFunc = options.valueFunc
    	if valueFunc then
    		local valueFuncType = type(valueFunc)
    		if valueFuncType == 'function' then
    			tidyVal = valueFunc
    		else
    			error('type error in option "valueFunc": expected function, got ' .. valueFuncType, 2)
    		end
    	end
    
    	local function mergeArgs(iterator, tables)
    		-- Accepts multiple tables as input and merges their keys and values into one table using the specified iterator.
    		-- If a value is already present it is not overwritten; tables listed earlier have precendence.
    		for _, t in ipairs(tables) do
    			for key, val in iterator(t) do
    				if metaArgs[key] == nil then
    					metaArgs[key] = tidyVal(key, val)
    				end
    			end
    		end
    	end
    
    	-- Set the order of precedence of the argument tables. If the variables are nil, nothing will be added to the table,
    	-- which is how we avoid clashes between the frame/parent args and the Lua args.
    	local argTables = {}
    	if options.parentFirst then
    		table.insert(argTables, pargs)
    		table.insert(argTables, fargs)
    	else
    		table.insert(argTables, fargs)
    		table.insert(argTables, pargs)
    	end
    	table.insert(argTables, luaArgs)
    
    	--[[
    	-- Define metatable behaviour. Arguments are stored in the metaArgs table, and are only fetched from the
    	-- argument tables once. Also, we keep a record in the metatable of when pairs and ipairs have been called,
    	-- so we do not run pairs and ipairs on fargs and pargs more than once. We also do not run ipairs on fargs
    	-- and pargs if pairs has already been run, as all the arguments will already have been copied over.
    	--]]
    	metatable.__index = function (t, key)
    		local val = metaArgs[key]
    		if val ~= nil then
    			return val
    		else
    			for i, argTable in ipairs(argTables) do
    				local argTableVal = tidyVal(argTable[key])
    				if argTableVal ~= nil then
    					metaArgs[key] = argTableVal
    					return argTableVal
    				end
    			end
    		end
    	end
    
    	metatable.__newindex = function (t, key, val)
    		if not options.readOnly and (not options.noOverwrite or args[key] == nil) then
    			metaArgs[key] = val
    		end
    	end
    
    	metatable.__pairs = function ()
    		if not metatable.donePairs then
    			mergeArgs(pairs, argTables)
    			metatable.donePairs = true
    			metatable.doneIpairs = true
    		end
    		return pairs(metaArgs)
    	end
    
    	metatable.__ipairs = function ()
    		if not metatable.doneIpairs then
    			mergeArgs(ipairs, argTables)
    			metatable.doneIpairs = true
    		end
    		return ipairs(metaArgs)
    	end
    	
    	return args
    end
    
    return arguments