ns Has Subpages

-- This module implements [[Template:Ns has subpages]]. -- While the template is fairly simple, this information is made available to -- Lua directly, so using a module means that we don't have to update the -- template as new namespaces are added.  local p = {}  function p._main(ns, frame) -- Get the current namespace if we were not passed one. if not ns then ns = mw.title.getCurrentTitle().namespace end  -- Look up the namespace table from mw.site.namespaces. This should work -- for a majority of cases. local nsTable = mw.site.namespaces[ns]  -- Try using string matching to get the namespace from page names. -- Do a quick and dirty bad title check to try and make sure we do the same -- thing as {{NAMESPACE}} in most cases. if not nsTable and type(ns) == 'string' and not ns:find('[<>|%[%]{}]') then local nsStripped = ns:gsub('^[_%s]*:', '') nsStripped = nsStripped:gsub(':.*$', '') nsTable = mw.site.namespaces[nsStripped] end  -- If we still have no match then try the {{NAMESPACE}} parser function, -- which should catch the remainder of cases. Don't use a mw.title object, -- as this would increment the expensive function count for each new page -- tested. if not nsTable then frame = frame or mw.getCurrentFrame() local nsProcessed = frame:callParserFunction('NAMESPACE', ns) nsTable = nsProcessed and mw.site.namespaces[nsProcessed] end  return nsTable and nsTable.hasSubpages end  function p.main(frame) local ns = frame:getParent().args[1] if ns then ns = ns:match('^%s*(.-)%s*$') -- trim whitespace ns = tonumber(ns) or ns end local hasSubpages = p._main(ns, frame) return hasSubpages and 'yes' or '' end  return p