Editing Module:Sandbox/Ahecht/Catalog lookup link

local p = {}

function p.main(frame)
	local args = {}
	local out = ''
	local defaultSeparator = ', '
	local lockIcon = {
		['free'] = '[[File:Lock-green.svg|9px|link=|alt=Freely accessible|Freely accessible]]',
		['registration'] = '[[File:Lock-blue-alt-2.svg|9px|link=|alt=Free registration required|Free registration required]]',
		['limited'] = '[[File:Lock-blue-alt-2.svg|9px|link=|alt=Free access subject to limited trial, subscription normally required|Free access subject to limited trial, subscription normally required]]',
		['subscription'] = '[[File:Lock-red-alt.svg|9px|link=|alt=Paid subscription required|Paid subscription required]]',
		}
	
	-- discard empty parameters and trim whitespace
	for k, v in pairs(frame:getParent().args) do
		if v and mw.ustring.match(v,'%S') then args[k] = mw.text.trim(v) end
	end
	
	if args[1] then
		local i = 1
		while args[i] do
			
			if i == 1 then -- if first item, add article link
				if args['article-link'] or args['article-name'] then
					if args['article-link'] then
						out = '[[' .. args['article-link'] .. '|' .. (args['article-name'] or args['article-link']) .. ']]'
					else
						out = args['article-name']
					end
					out = out .. (args['article-postfix'] or '') .. ' '
				else
					out = (args['article-postfix'] or '')
				end
			else -- otherwise, add separator
				if ( (not args[i+1]) and args['list-leadout'] ) then -- if last item
					if mw.ustring.match(mw.ustring.sub(args['list-leadout'],1,1), '[%a]') then
						out = out .. ' '
					end
					out = out .. args['list-leadout'] .. args['leadout-postfix'] .. ' '
				else -- if not last item or list-leadout isn't specified
					out = out .. (args['list-separator'] or defaultSeparator)
				end
			end
			
			-- generate link
			local item = (args['item-prefix'] or '') .. args[i] .. (args['item-postfix'] or '')
			if args['link-prefix'] then
				item = '[' .. args['link-prefix'] .. mw.uri.encode(args[i]) .. (args['link-postfix'] or '') .. ' '.. item .. ']'
				if lockIcon[args['url-access']] then
					item = item .. '<span style="padding-left:0.15em;">' .. lockIcon[args['url-access']] .. '</span>'
				end
			end
			out = out .. item
			i = i + 1
		end
	end
	
	if lockIcon[args['url-access']] or args['plain-links'] then
		out = '<span class="plainlinks">' .. out .. '</span>'
	end
	
	return out
end

return p