Module:Paramvalidate

This module is used to validate template inputs.

Supported parameters

Parameter	Check	Result	Function
{{{image}}}	Check if the string ends with .extension	Category:Pages with invalid image argument in template	checkImageExtension
{{{image}}}	Check if the image exists as a file	Category:Pages with non-existent image in template	checkImageMetadata
{{{image}}}	Check if the image has sufficient width (>=640px) for the infobox	Category:Pages with non-sufficient width image in infobox	checkImageMetadata

---

local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType
local checkTypeForNamedArg = libraryUtil.checkTypeForNamedArg
local mArguments -- initialize lazily
local p = {}
local categories = {}


--- Format table of strings into category wikitext
--- @return string
local function tableToCategory()
	local wikitext = {}
	for _, category in ipairs(categories) do
		table.insert(wikitext, string.format('[[Category:%s]]', category))
	end
	return table.concat(wikitext)
end

--- Validates if the given image file extension is one of the supported types (gif, png, jpg, jpeg, webp).
--- Return true if the extension is valid, false if isn't (the input parameter is likely incorrect)
--- @param image string - The image argument of the template
--- @return boolean
local function checkImageExtension(image)
	local EXTENSIONS = {
		'gif',
		'png',
		'jpg',
		'JPG',
		'jpeg',
		'svg',
		'webp'
	}

	for _, extension in ipairs(EXTENSIONS) do
		local pattern = "%." .. extension .. "$"
		if string.match(image, pattern) then
			return true
		end
	end

	table.insert(categories, 'Pages with invalid image argument in template')
	return false
end

--- Check if the image actually exists and whether it has the sufficient width for the infobox
--- @param image string - The image argument of the template
--- @return nil
local function checkImageMetadata(image)
	local MIN_WIDTH = 640 -- 320px is the infobox width, 2x for HiDPI screens
	local MAX_HEIGHT = 960

	local title = mw.title.makeTitle('File', image)
	local file = title.file

	if not title.exists or not file or not file.exists then
		table.insert(categories, 'Pages with non-existent  image in template')
		return
	end

	if file.height < MAX_HEIGHT and file.width < MIN_WIDTH then
		table.insert(categories, 'Pages with non-sufficient width image in infobox')
	end
end

--- Performs checks on the image argument
--- @param image string - The image argument of the template
--- @return nil
function p.checkImage(image)
	local isImageParameterValid = checkImageExtension(image)
	-- Only continue if the parameter is valid
	if isImageParameterValid then
		checkImageMetadata(image)
	end
end

--- Retrieves template arguments from the frame invoke function and pass to the main function
function p.paramvalidate(frame)
	mArguments = require('Module:Arguments')
	return p._paramvalidate(mArguments.getArgs(frame))
end

--- Validate template parameters and return the wikitext
--- @param args table - Template arguments to be validated
--- @return string|nil
function p._paramvalidate(args)
	checkType('_paramvalidate', 1, args, 'table')

	if args['image'] and args['image'] ~= '' then
		checkTypeForNamedArg('_paramvalidate', 'image', args.image, 'string', false)
		p.checkImage(args['image'])
	end

	-- Only add category if it is content pages
	if mw.title.getCurrentTitle().isContentPage then
		return tableToCategory()
	end
end

return p