Module:File link

    From Nonbinary Wiki
    Revision as of 13:38, 30 May 2014 by wikipedia>Mr. Stradivarius (add page, class and lang parameters)

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

    -- This module provides a library for formatting image wikilinks.
    
    local libraryUtil = require('libraryUtil')
    local checkType = libraryUtil.checkType
    
    local image = {}
    
    function image.new(filename)
    	checkType('image.new', 1, filename, 'string', true)
    	local obj, data = {}, {}
    	
    	local checkSelf = libraryUtil.makeCheckSelfFunction(
    		'image',
    		'image',
    		obj,
    		'image object'
    	)
    	
    	-- Set the filename if we were passed it as an input to image.new.
    	if filename then
    		data.theName = filename
    	end
    	
    	function data:name(s)
    		checkSelf(self, 'image:name')
    		checkType('image:name', 1, s, 'string')
    		data.theName = s
    		return self
    	end
    	
    	function data:format(s, filename)
    		checkSelf(self, 'image:format')
    		checkType('image:format', 1, s, 'string', true)
    		checkType('image:format', 2, format, 'string', true)
    		local validFormats = {
    			thumb = true,
    			thumbnail = true,
    			frame = true,
    			framed = true,
    			frameless = true
    		}
    		if s == nil or validFormats[s] then
    			data.theFormat = s
    			data.theFormatFilename = filename
    		else
    			error(string.format(
    				"bad argument #1 to 'image:format' ('%s' is not a valid format)",
    				s
    			), 2)
    		end
    		return self
    	end
    
    	local function sizeError(methodName)
    		-- Used for formatting duplication errors in size-related methods.
    		error(string.format(
    			"duplicate size argument detected in '%s'"
    			.. " ('upright' cannot be used in conjunction with height or width)",
    			methodName
    		), 3)
    	end
    	
    	function data:width(px)
    		checkSelf(self, 'image:width')
    		checkType('image:width', 1, px, 'number', true)
    		if px and data.isUpright then
    			sizeError('image:width')
    		end
    		data.theWidth = px
    		return self
    	end
    	
    	function data:height(px)
    		checkSelf(self, 'image:height')
    		checkType('image:height', 1, px, 'number', true)
    		if px and data.isUpright then
    			sizeError('image:height')
    		end
    		data.theHeight = px
    		return self
    	end
    	
    	function data:upright(isUpright, factor)
    		checkSelf(self, 'image:upright')
    		checkType('image:upright', 1, isUpright, 'boolean', true)
    		checkType('image:upright', 2, factor, 'number', true)
    		if isUpright and (data.theWidth or data.theHeight) then
    			sizeError('image:upright')
    		end
    		data.isUpright = isUpright
    		data.uprightFactor = factor
    		return self
    	end
    	
    	function data:resetSize()
    		checkSelf(self, 'image:resetSize')
    		for i, field in ipairs{'theWidth', 'theHeight', 'isUpright', 'uprightFactor'} do
    			data[field] = nil
    		end
    		return self
    	end
    	
    	function data:location(s)
    		checkSelf(self, 'image:location')
    		checkType('image:location', 1, s, 'string', true)
    		local validLocations = {
    			right = true,
    			left = true,
    			center = true,
    			none = true
    		}
    		if s == nil or validLocations[s] then
    			data.theLocation = s
    		else
    			error(string.format(
    				"bad argument #1 to 'image:location' ('%s' is not a valid location)",
    				s
    			), 2)
    		end
    		return self
    	end
    	
    	function data:alignment(s)
    		checkSelf(self, 'image:alignment')
    		checkType('image:alignment', 1, s, 'string', true)
    		local validAlignments = {
    			baseline = true,
    			middle = true,
    			sub = true,
    			super = true,
    			['text-top'] = true,
    			['text-bottom'] = true,
    			top = true,
    			bottom = true
    		}
    		if s == nil or validAlignments[s] then
    			data.theAlignment = s
    		else
    			error(string.format(
    				"bad argument #1 to 'image:alignment' ('%s' is not a valid alignment)",
    				s
    			), 2)
    		end
    		return self
    	end
    	
    	function data:border(hasBorder)
    		checkSelf(self, 'image:border')
    		checkType('image:border', 1, hasBorder, 'boolean', true)
    		data.hasBorder = hasBorder
    		return self
    	end
    	
    	function data:link(s)
    		checkSelf(self, 'image:link')
    		checkType('image:link', 1, s, 'string', true)
    		data.theLink = s
    		return self
    	end
    	
    	function data:alt(s)
    		checkSelf(self, 'image:alt')
    		checkType('image:alt', 1, s, 'string', true)
    		data.theAlt = s
    		return self
    	end
    	
    	function data:page(num)
    		checkSelf(self, 'image:page')
    		checkType('image:page', 1, num, 'number', true)
    		data.thePage = s
    		return self
    	end
    	
    	function data:class(s)
    		checkSelf(self, 'image:class')
    		checkType('image:class', 1, s, 'string', true)
    		data.theClass = s
    		return self
    	end
    	
    	function data:lang(s)
    		checkSelf(self, 'image:lang')
    		checkType('image:lang', 1, s, 'string', true)
    		data.theLang = s
    		return self
    	end
    	
    	function data:caption(s)
    		checkSelf(self, 'image:caption')
    		checkType('image:caption', 1, s, 'string', true)
    		data.theCaption = s
    		return self
    	end
    	
    	function data:render()
    		checkSelf(self, 'image:render')
    		local ret = {}
    		
    		-- Image name.
    		if not data.theName then
    			error('image:render: no image name was found')
    		end
    		ret[#ret + 1] = 'File:' .. data.theName
    		
    		-- Image format
    		if data.theFormat and data.theFormatFilename then
    			ret[#ret + 1] = data.theFormat .. '=' .. data.theFormatFilename
    		elseif data.theFormat then
    			ret[#ret + 1] = data.theFormat
    		end
    		
    		-- Border
    		if data.hasBorder then
    			ret[#ret + 1] = 'border'
    		end
    		
    		-- Location
    		ret[#ret + 1] = data.theLocation
    
    		-- Alignment
    		ret[#ret + 1] = data.theAlignment
    		
    		-- Size
    		if data.isUpright and data.uprightFactor then
    			ret[#ret + 1] = 'upright=' .. tostring(data.uprightFactor)
    		elseif data.isUpright then
    			ret[#ret + 1] = 'upright'
    		elseif data.theWidth and data.theHeight then
    			ret[#ret + 1] = string.format('%dx%dpx', data.theWidth, data.theHeight)
    		elseif data.theWidth then
    			ret[#ret + 1] = tostring(data.theWidth) .. 'px'
    		elseif data.theHeight then
    			ret[#ret + 1] = string.format('x%dpx', data.theHeight)
    		end
    		
    		-- Render named parameters.
    		-- That includes link, alt, page, class, and lang.
    		do
    			local namedParameters = {'link', 'alt', 'page', 'class', 'lang'}
    			for i, parameter in ipairs(namedParameters) do
    				local dataField = 'the' .. parameter:sub(1, 1):upper() .. parameter:sub(2, -1)
    				local value = data[dataField]
    				if value then
    					ret[#ret + 1] = parameter .. '=' .. tostring(value)
    				end
    			end
    		end
    
    		-- Caption
    		ret[#ret + 1] = data.theCaption
    		
    		return string.format('[[%s]]', table.concat(ret, '|'))
    	end
    	
    	local privateFields = {
    		theName = true,
    		theFormat = true,
    		theFormatFilename = true,
    		theWidth = true,
    		theHeight = true,
    		isUpright = true,
    		uprightFactor = true,
    		theLocation = true,
    		theAlignment = true,
    		hasBorder = true,
    		theLink = true,
    		theAlt = true,
    		theCaption = true
    	}
    	
    	local readOnlyFields = {}
    	for field in pairs(data) do
    		readOnlyFields[field] = true
    	end
    	readOnlyFields.theName = nil -- This is set if a filename is given to image.new, so remove it.
    	
    	local function restrictedFieldError(key, restriction)
    		error(string.format(
    			"image object field '%s' is %s",
    			tostring(key),
    			restriction
    		), 3)
    	end
    	
    	setmetatable(obj, {
    		__index = function (t, key)
    			if privateFields[key] then
    				restrictedFieldError(key, 'private')
    			else
    				return data[key]
    			end
    		end,
    		__newindex = function (t, key, value)
    			if privateFields[key] then
    				restrictedFieldError(key, 'private')
    			elseif readOnlyFields[key] then
    				restrictedFieldError(key, 'read-only')
    			else
    				data[key] = value
    			end
    		end,
    		__tostring = function (t)
    			return t:render()
    		end,
    		__pairs = function ()
    			local temp = {}
    			for k, v in pairs(data) do
    				if not privateFields[k] then
    					temp[k] = v
    				end
    			end
    			return pairs(temp)
    		end
    	})
    	
    	return obj
    end
    
    return image