How do i write my own pre-save transform?

Question

As described here, the mediawiki parser allows for a pre-save transform which will automatically replace wikitext with something else.

How do I create my own?

I did find this, but I can't even be sure it's relevant anymore. http://mediawiki.sourcearchive.com/documentation/1.13.3/classArticle_a0d27b9b92f688ea124b1f1c4c0b60018.html

Answer 1

In modern MediaWiki versions (v1.21+), one way to do this could be to:

1. Write your own ContentHandler classes, extending WikiTextContent and WikitextContentHandler. These could be as simple as:

   class MyContentHandler extends WikitextContentHandler {
       protected function getContentClass() {
           return 'MyContent';
       }
   }
   class MyContent extends WikitextContent {
       // TODO: override preSaveTransform() here
   }
   

2. In the Content subclass, override the preSaveTransform() method, e.g. like this (if you want to modify the wikitext after the normal PST pass):

   public function preSaveTransform( Title $title, User $user, ParserOptions $popts ) {
       $content = parent::preSaveTransform( $title, $user, $popts );
       $orig = $text = $content->getNativeData();
       // ...modify $text here...
       return ( $orig === $text ) ? $content : new static( $text );
   }
   

3. Register your new ContentHandler as the handler for ordinary wiki pages using $wgContentHandlers in LocalSettings.php:

   $wgContentHandlers[CONTENT_MODEL_WIKITEXT] = 'MyContentHandler';
   

(Warning: I believe this method should work, but I have not actually tested it! Use at your own risk. Improvements and bug reports welcome.)

Answer 2

The replacement of the signature is hard-coded in mediawiki/core.

I don't know any way to do the same thing without changing core files (which, btw, isn't a good idea). You could use a parser function or create a tag extension to achieve what you want to do in a similar way.