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Module:Check for unknown parameters is used to check for uses of unknown parameters in a template or module. It may be appended to a template at the end or called directly from a module.
Unnamed (positional) parameters can be added too:|1|2|arg1|arg2|....
Lua patterns (similar toregular expressions) usage with parameters is also supported (such as:|regexp1=header[%d]+,|regexp2=date[1-9],|regexp3=data[%d]+[abc]?). This is useful when there are many known parameters which use a systematic pattern.
|unknown= – what happens when an uknown parameter is used. Typically use either a tracking category to place pages that use unknown parameters, or an error.
|preview= – the text to be displayed when in preview mode and an unknown parameter is used.
The_VALUE_ keyword, if used, will be changed to the name of the parameter. This is useful for either sorting the entries in a tracking category, or for provide more explicit information.
|ignoreblank=1 – by default, the module makes no distinction between a defined-but-blank parameter and a non-blank parameter. That is, both unlisted|foo=x and|foo= are reported. To only track non-blank parameters use|ignoreblank=1.
|showblankpositional=1 – by default, the module ignores blank positional parameters. That is, an unlisted|2= is ignored. Toinclude blank positional parameters in the tracking use|showblankpositional=1.
-- This module may be used to compare the arguments passed to the parent-- with a list of arguments, returning a specified result if an argument is-- not on the listlocalp={}localfunctiontrim(s)returns:match('^%s*(.-)%s*$')endlocalfunctionisnotempty(s)returnsands:match('%S')endlocalfunctionclean(text)-- Return text cleaned for display and truncated if too long.-- Strip markers are replaced with dummy text representing the original wikitext.localpos,truncatedlocalfunctiontruncate(text)iftruncatedthenreturn''endifmw.ustring.len(text)>25thentruncated=truetext=mw.ustring.sub(text,1,25)..'...'endreturnmw.text.nowiki(text)endlocalparts={}forbefore,tag,remainderintext:gmatch('([^\127]*)\127[^\127]*%-(%l+)%-[^\127]*\127()')dopos=remaindertable.insert(parts,truncate(before)..'<'..tag..'>...</'..tag..'>')endtable.insert(parts,truncate(text:sub(posor1)))returntable.concat(parts)endfunctionp._check(args,pargs)iftype(args)~="table"ortype(pargs)~="table"then-- TODO: error handlingreturnend-- create the list of known args, regular expressions, and the return stringlocalknownargs={}localregexps={}fork,vinpairs(args)doiftype(k)=='number'thenv=trim(v)knownargs[v]=1elseifk:find('^regexp[1-9][0-9]*$')thentable.insert(regexps,'^'..v..'$')endend-- loop over the parent args, and make sure they are on the listlocalignoreblank=isnotempty(args['ignoreblank'])localshowblankpos=isnotempty(args['showblankpositional'])localvalues={}fork,vinpairs(pargs)doiftype(k)=='string'andknownargs[k]==nilthenlocalknownflag=falsefor_,regexpinipairs(regexps)doifmw.ustring.match(k,regexp)thenknownflag=truebreakendendifnotknownflagand(notignoreblankorisnotempty(v))thentable.insert(values,clean(k))endelseiftype(k)=='number'andknownargs[tostring(k)]==nilthenlocalknownflag=falsefor_,regexpinipairs(regexps)doifmw.ustring.match(tostring(k),regexp)thenknownflag=truebreakendendifnotknownflagand(showblankposorisnotempty(v))thentable.insert(values,k..' = '..clean(v))endendend-- add results to the output tableslocalres={}if#values>0thenlocalunknown_text=args['unknown']or'Found _VALUE_, 'ifmw.getCurrentFrame():preprocess("{{REVISIONID}}")==""thenlocalpreview_text=args['preview']ifisnotempty(preview_text)thenpreview_text=require('Module:If preview')._warning({preview_text})elseifpreview==nilthenpreview_text=unknown_textendunknown_text=preview_textendfor_,vinpairs(values)do-- Fix odd bug for | = which gets stripped to the empty string and-- breaks category linksifv==''thenv=' 'end-- avoid error with v = 'example%2' ("invalid capture index")localr=unknown_text:gsub('_VALUE_',{_VALUE_=v})table.insert(res,r)endendreturntable.concat(res)endfunctionp.check(frame)localargs=frame.argslocalpargs=frame:getParent().argsreturnp._check(args,pargs)endreturnp