Module:Suppress categories

 -- This is a simple module to strip categories from wikitext. It does
 -- not support nested links or magic words like __TOC__, etc. Even so,
 -- it should still handle most categories.

 localp={}

 -- Detects if a category link is valid or not. If it is valid,
 -- the function returns the blank string. If not, the input
 -- is returned with no changes.
 localfunctionprocessCategory(all,submatch)
 localbeforePipe=mw.ustring.match(submatch,'^(.-)[%s_]*|[%s_]*.-$')
 beforePipe=beforePipeorsubmatch
 ifmw.ustring.match(beforePipe,'[%[%]<>{}%c\n]')then
 returnall
 else
 return''
 end
 end

 -- Preprocess the content if we aren't being called from #invoke,
 -- and pass it to gsub to remove valid category links.
 localfunctionsuppress(content,isPreprocessed)
 ifnotisPreprocessedthen
 content=mw.getCurrentFrame():preprocess(content)
 end
 content=mw.ustring.gsub(
 content,
 '(%[%[[%s_]*[cC][aA][tT][eE][gG][oO][rR][yY][%s_]*:[%s_]*(.-)[%s_]*%]%])',
 processCategory
 )
 returncontent
 end

 -- Get the content to suppress categories from, and find
 -- whether the content has already been preprocessed. (If the
 -- module is called from #invoke, it has been preprocessed already.)
 functionp.main(frame)
 localcontent,isPreprocessed
 ifframe==mw.getCurrentFrame()then
 content=frame:getParent().args[1]
 ifframe.args[1]then
 content=frame.args[1]
 end
 isPreprocessed=true
 else
 content=frame
 isPreprocessed=false
 end
 returnsuppress(content,isPreprocessed)
 end

 returnp