Module:File link/sandbox explained

-- This module provides a library for formatting file wikilinks.

local yesno = require('Module:Yesno')local checkType = require('libraryUtil').checkType

local p =

function p._main(args) checkType('_main', 1, args, 'table')

-- This is basically libraryUtil.checkTypeForNamedArg, but we are rolling our -- own function to get the right error level. local function checkArg(key, val, level) if type(val) ~= 'string' then error(string.format("type error in '%s' parameter of '_main' (expected string, got %s)", key, type(val) ), level) end end

local ret =

-- Adds a positional parameter to the buffer. local function addPositional(key) local val = args[key] if not val then return nil end checkArg(key, val, 4) ret[#ret + 1] = val end

-- Adds a named parameter to the buffer. We assume that the parameter name -- is the same as the argument key. local function addNamed(key) local val = args[key] if not val then return nil end checkArg(key, val, 4) ret[#ret + 1] = key .. '=' .. val end

-- Filename checkArg('file', args.file, 3) ret[#ret + 1] = 'File:' .. args.file

-- Format if args.format then checkArg('format', args.format) if args.formatfile then checkArg('formatfile', args.formatfile) ret[#ret + 1] = args.format .. '=' .. args.formatfile else ret[#ret + 1] = args.format end end

-- Border if yesno(args.border) then ret[#ret + 1] = 'border' end

addPositional('location') addPositional('alignment') addPositional('size') addNamed('upright') addNamed('link') addNamed('alt') addNamed('page') addNamed('class') addNamed('lang') addNamed('start') addNamed('end') addNamed('thumbtime') addPositional('caption')

return string.format('%s', table.concat(ret, '|'))end

function p.main(frame) local origArgs = require('Module:Arguments').getArgs(frame,) if not origArgs.file then error("'file' parameter missing from ", 0) end

-- Copy the arguments that were passed to a new table to avoid looking up -- every possible parameter in the frame object. local args = for k, v in pairs(origArgs) do -- Make _BLANK a special argument to add a blank parameter. For use in -- conditional templates etc. it is useful for blank arguments to be -- ignored, but we still need a way to specify them so that we can do -- things like . if v

'_BLANK' then v = end args[k] = v end return p._main(args)end

return p