Manual:Hooks/ArticlePageDataBefore

Details

 * $article: WikiPage object being requested.
 * $fields: fields to load from the database

As MediaWiki reads in the page data, this hook allows you to read more data fields related to the same database row than what is specified in WikiPage::selectFields. You specify more data fields by adding them to $fields parameter. Such data fields can then be manipulated from  ArticlePageDataAfter.