Module:Clickable button 2
-- This module implements {{clickable button 2}}.
 
 local yesno = require('Module:Yesno')
 
 local p = {}
 
 function p.main(frame)
 	local args = require('Module:Arguments').getArgs(frame, {
 		wrappers = 'Template:Clickable button 2'
 	})
 	return p.luaMain(args)
 end
 
 function p.luaMain(args)
 	if not args[1] and not args.url then
 		return ''
 	end
 	local data = p.makeLinkData(args)
 	local link = p.renderLink(data)
 	local trackingCategories = p.renderTrackingCategories(args)
 	return link .. trackingCategories
 end
 
 function p.makeLinkData(args)
 	local data = {}
 
 	-- Get the link and display values, and find whether we are outputting a
 	-- wikilink or a URL.
 	if args.url then
 		data.isUrl = true
 		data.link = args.url
 		if args[1] then
 			data.display = args[1]
 		else
 			data.display = args.url
 		end
 	else
 		data.isUrl = false
 		data.link = args[1]
 		if args[2] then
 			data.display = args[2]
 		else
 			data.display = args[1]
 		end
 	end
 
 	-- Classes
 	local class = args.class and args.class:lower()
 	data.classes = {}
 	if class == 'ui-button-green'
 		or class == 'ui-button-blue'
 		or class == 'ui-button-red'
 	then
 		table.insert(
 			data.classes,
 			'submit ui-button ui-widget ui-state-default ui-corner-all'
 				.. ' ui-button-text-only ui-button-text'
 		)
 	else
 		table.insert(data.classes, 'mw-ui-button')
 	end
 	if class then
 		table.insert(data.classes, class)
 	end
 
 	-- Styles
 	do
 		--[[
 		-- Check whether we are on the same page as we have specified in
 		-- args[1], but not if we are using a URL link, as then args[1] is only
 		-- a display value. If we are currently on the page specified in
 		-- args[1] make the button colour darker so that it stands out from
 		-- other buttons on the page.
 		--]]
 		local success, linkTitle, currentTitle
 		if not data.isUrl then
 			currentTitle = mw.title.getCurrentTitle()
 			success, linkTitle = pcall(mw.title.new, args[1])
 		end
 		if success
 			and linkTitle
 			and mw.title.equals(currentTitle, linkTitle)
 		then
 			if class == 'ui-button-blue'
 				or class == 'mw-ui-progressive'
 			then
 				data.backgroundColor = '#2962CB'
 			elseif class == 'ui-button-green'
 				or class == 'mw-ui-constructive'
 			then
 				data.backgroundColor = '#008B6D'
 			elseif class == 'ui-button-red'
 				or class == 'mw-ui-destructive'
 			then
 				data.backgroundColor = '#A6170F'
 			else
 				data.backgroundColor = '#CCC'
 				data.color = '#666'
 			end
 		end
 		-- Add user-specified styles.
 		data.style = args.style
 	end
 
 	return data
 end
 
 function p.renderLink(data)
 	-- Render the display span tag.
 	local display
 	do
 		local displaySpan = mw.html.create('span')
 		for i, class in ipairs(data.classes or {}) do
 			displaySpan:addClass(class)
 		end
 		displaySpan
 			:attr('role', 'button')
 			:attr('aria-disabled', 'false')
 			:css{
 				['background-color'] = data.backgroundColor,
 				color = data.color
 			}
 		if data.style then
 			displaySpan:cssText(data.style)
 		end
 		displaySpan:wikitext(data.display)
 		display = tostring(displaySpan)
 	end
 
 	-- Render the link
 	local link 
 	if data.isUrl then
 		link = string.format('[%s %s]', data.link, display)
 	else
 		link = string.format('[[%s|%s]]', data.link, display)
 	end
 
 	return string.format('&lt;span class=&quot;plainlinks&quot;&gt;%s&lt;/span&gt;', link)
 end
 
 function p.renderTrackingCategories(args)
 	if yesno(args.category) == false then
 		return ''
 	end
 	local class = args.class and args.class:lower()
 	if class == 'ui-button-green'
 		or class == 'ui-button-blue'
 		or class == 'ui-button-red'
 	then
 		return '[[Category:Pages using old style ui-button-color]]'
 	else
 		return ''
 	end
 end