-- Creates a slideshow gallery where the order is randomised. Intended for use on portal pages. local p = {} local excerptModule =  require('Module:Excerpt/portals') local randomModule = require('Module:Random') local redirectModule = require('Module:Redirect')  function cleanupArgs(argsTable) 	local cleanArgs = {} 	for key, val in pairs(argsTable) do 		if type(val) == 'string' then 			val = val:match('^%s*(.-)%s*$') 			if val ~=  then 				cleanArgs[key] = val 			end 		else 			cleanArgs[key] = val 		end 	end 	return cleanArgs end  function normaliseCssMeasurement(input) 	local suffix = string.reverse(string.sub(string.reverse(input), 1, 2)) 	if ( suffix == 'px' ) or ( suffix == 'em' ) or ( string.sub(suffix, 2, 2) == '%' ) then 		return input 	else 		return input .. 'px' 	end end  function isDeclined(val) 	if not val then return false end 	local declinedWords = " decline declined exclude excluded false none not no n off omit omitted remove removed " 	return string.find(declinedWords , ' '..val..' ', 1, true ) and true or false end  function makeOutput(galleryLines, maxWidth, containerClassName, nonRandom) 	local randomiseArgs = {	['t'] = galleryLines } 	local sortedLines = nonRandom and galleryLines or randomModule.main('array', randomiseArgs) 	for i = 1, #sortedLines do 		-- insert a switcher-label span just after the first pipe (which has already been escaped as  instead the | character) 		sortedLines[i] = sortedLines[i]:gsub( 			"%{%{%!%}%}", 			'Image ' .. tostring(i) .. '', 			1) 	end 	local galleryContent = table.concat(sortedLines, '\n') 	local output = '' 	return output end  function makeGalleryLine(file, caption, credit) 	local title = mw.title.new(file, "File" ) 	if not title 	then 		return "File:Blank.png" 	end 	local creditLine = ( credit and '' .. credit .. '' or  ) 	return title.prefixedText .. '' .. ( caption or  ) .. creditLine end  function makeGalleryLinesTable(args) 	local galleryLinesTable = {} 	local i = 1 	while args[i] do 		table.insert(galleryLinesTable, makeGalleryLine(args[i], args[i+1], args['credit' .. (i+1)/2])) 		i = i + 2 	end 	return galleryLinesTable  end  function hasCaption(line) 	local caption = mw.ustring.match(line, ".-(.*)") 	-- require caption to exist with more than 5 characters (avoids sizes etc being mistaken for captions) 	return caption and #caption>5 and true or false end  function extractGalleryFiles(wikitext) 	local gallery = mw.ustring.match(wikitext, '<gallery.->%s*(.-)%s*</gallery>') 	if not gallery then 		return false 	end 	gallery = mw.ustring.gsub(gallery, '|', '') 	return mw.text.split(gallery, '%c') end  function extractRegularFiles(wikitext) 	local files = {} 	local frame = mw.getCurrentFrame() 	local expand = function(template) 		return frame:preprocess(template) 	end 	for file in mw.ustring.gmatch(wikitext, '%b[]' ) do 		-- remove keywords that don't work in galleries 		file = mw.ustring.gsub(file, '|%s*thumb%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*thumbnail%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*border%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*left%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*right%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*center%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*centre%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*baseline%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*sub%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*super%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*top%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*text%-top%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*bottom%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*text%-bottom%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*framed?%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*frameless%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*upright%s*[0-9%.]*%s*([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*upright%s*=.-([|%]])', '%1') 		file = mw.ustring.gsub(file, '|%s*link%s*=.-([|%]])', '%1') 		-- remove spaces prior to captions (which cause pre-formatted text) 		file = mw.ustring.gsub(file, '|%s*', '|') 		-- remove sizes, which sometimes get mistaken for captions 		file = mw.ustring.gsub(file, '|%s*%d*x?%d+%s*px%s*([|%]])', '%1') 		-- expand templates 		file = mw.ustring.gsub(file, '{%b{}}', expand) 		-- remove loose closing braces which don't have matching opening braces 		file = mw.ustring.gsub(file, '}}', ) 		-- remove loose opening braces which don't have matching closing braces (and the subsequent content, which is probably just a template name) 		file = mw.ustring.gsub(file, '{{.-([|%]])', '$1') 		-- replace pipes and equals (which would otherwise break the  syntax) 		file = mw.ustring.gsub(file, '|%s*alt%s*=', 'alt=') 		file = mw.ustring.gsub(file, '|', '') 		file = mw.ustring.gsub(file, '=', '') 		-- remove linebreaks 		file = mw.ustring.gsub(file, '\n\n', '') 		file = mw.ustring.gsub(file, '\n', ) 		-- remove surrounding square brackets 		file = mw.ustring.gsub(file, '^%[%[', ) 		file = mw.ustring.gsub(file, '%]%]$', ) 		table.insert(files, file) 	end 	return files end  function makeTranscludedGalleryLinesTables(args) 	local namespaceNumber = function(pagetitle) 		local titleObject = mw.title.new(pagetitle) 		return titleObject and titleObject.namespace 	end 	local lines = {} 	local i = 1 	while args[i] do 		if namespaceNumber(args[i]) == 6 then -- file namespace 			-- args[i] is either just the filename, or uses syntax File:Name.jpg##Caption##Credit 			local parts = mw.text.split(args[i], '##%s*') 			local filename = parts[1] 			local caption = args['caption'..i] or parts[2] or false 			local credit = args['credit'..i] or parts[3] or false 			local line = makeGalleryLine(filename, caption, credit) 			table.insert(lines, line) 		else 			local content, pagename = excerptModule.getContent(args[i]) 			if not pagename then 				return error('Cannot read a valid page for "' .. args[i] .. '"', 0) 			elseif not content then 				return error('No content found on page "' .. args[i] .. '"', 0) 			end 			if args['section'..i] then 				content = excerptModule.getSection(content, args['section'..i]) or  			end 			content = excerptModule.cleanupText(content, {keepSubsections=true}) -- true means keep subsections 	 			local galleryFiles = extractGalleryFiles(content) 			if galleryFiles then 				for _, f in pairs(galleryFiles) do 					if hasCaption(f) then 						local filename = string.gsub(f, '.*', ) 						local isOkay = excerptModule.checkImage(filename) 						if isOkay then 							table.insert(lines, f.." ("..pagename.." থেকে)") 						end 					end 				end 			end 	 			local otherFiles = excerptModule.parse(content, {fileflags="1-100", filesOnly=true}) 			if otherFiles then 				for _, f in pairs(extractRegularFiles(otherFiles)) do 					if f and f ~=  and mw.ustring.sub(f, 1, 5) == 'File:' and hasCaption(f) then 						table.insert(lines, f.." ("..pagename.." থেকে)") 					end 				end 			end 		 		end 		i = i + 1 	end 	return ( #lines > 0 ) and lines or error('No images found') end  p._main = function(args, transclude, extraClassName) 	if not args[1] then 		return error(linked and 'No page specified' or 'No page specified', 0) 	end 	local lines = transclude and makeTranscludedGalleryLinesTables(args) or makeGalleryLinesTable(args) 	local classNames = 'randomSlideshow-container' 	if extraClassName then classNames = classNames .. ' ' .. extraClassName end 	return makeOutput(lines, args.width or '100%', classNames, isDeclined(args.random)) end  p.main = function(frame) 	local parent = frame.getParent(frame) 	local parentArgs = parent.args 	local args = cleanupArgs(parentArgs) 	local output = p._main(args, false) 	return frame:extensionTag{ name='templatestyles', args = { src='Module:Random slideshow/styles.css'} }  		.. frame:preprocess(output) end  p.transclude = function(frame) 	local parent = frame.getParent(frame) 	local parentArgs = parent.args 	local args = cleanupArgs(parentArgs) 	local output = p._main(args, true) 	return frame:extensionTag{ name='templatestyles', args = { src='Module:Random slideshow/styles.css'} }  		.. frame:preprocess(output) end  return p