If the first unnamed parameter is not an empty string, the template returns it as a piped wiki-link using the |prefix= as a namespace or interwiki prefix. Otherwise it returns the second unnamed parameter.
This is only useful when the first parameter is a {{#invoke: }} of a Lua module that may return a value or nothing. Because it uses the {{#invoke: }} just once, it simplifies the coding of infoboxes and reduces the calls to a module.
The |after= parameter is emitted immediately after the wikilink. This is useful, e.g., for tracking categories.
The |linktext= parameter allows the link text of the wikilink to be overridden. Otherwise, it will be the same as the first positional argument.
Examples
edit{{If then wikilink |{{#invoke:WikidataIB |getSiteLink |wiki=enwikisource |qid=Q56862211}} | prefix=s:en:|after=!}}→ History of Oregon Newspapers!{{If then wikilink |{{#invoke:WikidataIB |getSiteLink |wiki=enwikisource |qid=Q56862211}} | prefix=s:en:|linktext=Wikisource}}→ Wikisource