New hook, AfterParserFetchFileAndTitle

It is needed for PageImages to collect information about galleries, improving results
for Commons mainspace.

Bug: 66510
Change-Id: I3136d648ef2c1841767db0ab33855cd168e3de3e

docs/hooks.txt

@@ -326,6 +326,13 @@ $revCount: Number of revisions in the XML file
 $sRevCount: Number of successfully imported revisions
 $pageInfo: associative array of page information
 
+'AfterParserFetchFileAndTitle': After an image gallery is formed by Parser,
+just before adding its HTML to parser output.
+$parser: Parser object that called the hook
+$ig: Gallery, an object of one of the gallery classes (inheriting from
+ImageGalleryBase)
+$html: HTML generated by the gallery
+
 'AjaxAddScript': Called in output page just before the initialisation
 of the javascript ajax engine. The hook is only called when ajax
 is enabled ( $wgUseAjax = true; ).

includes/gallery/ImageGalleryBase.php

@@ -258,6 +258,14 @@ abstract class ImageGalleryBase extends ContextSource {
 		array_unshift( $this->mImages, array( &$title, $html, $alt, $link, $handlerOpts ) );
 	}
 
+	/**
+	 * Returns the list of images this gallery contains
+	 * @return array
+	 */
+	public function getImages() {
+		return $this->mImages;
+	}
+
 	/**
 	 * isEmpty() returns true if the gallery contains no images
 	 * @return bool

includes/parser/Parser.php

@@ -5369,6 +5369,7 @@ class Parser {
 			$ig->add( $title, $label, $alt, $link, $handlerOptions );
 		}
 		$html = $ig->toHTML();
+		wfRunHooks( 'AfterParserFetchFileAndTitle', array( $this, $ig, &$html ) );
 		wfProfileOut( __METHOD__ );
 		return $html;
 	}