Allow skins to opt out of sortable and collapsible

core.diff

diff --git a/includes/skins/Skin.php b/includes/skins/Skin.php
index 44a9eb09a9..c90d4b0da2 100644
--- a/includes/skins/Skin.php
+++ b/includes/skins/Skin.php
@@ -164,6 +164,40 @@ abstract class Skin extends ContextSource {
 	 */
 	public function initPage( OutputPage $out ) {
 		$this->preloadExistence();
+		$out->addJsConfigVars( [
+			'wgCollapsible' => $this->supportsFeature( 'table-sorting' ),
+			'wgSortable' => $this->supportsFeature( 'table-sorting' )
+		] );
+	}
+
+	/**
+	 * Maps features to string tests.
+	 */
+	private $supportedFeatures = [];
+
+	/**
+	 * Is a certain feature present in the current OutputPage and supported by the skin?
+	 * @param string $feature
+	 * @param OutputPage $out
+	 * @return bool
+	 */
+	protected function supportsFeature( $feature, $out ) {
+		$supported = isset( $this->supportedFeatures[$feature] );
+		if ( $supported ) {
+			return $supported;
+		}
+		switch ( $feature ) {
+			case 'table-sorting':
+				$supported = strpos( $out->getHTML(), 'sortable' ) !== false;
+				break;
+			case 'collapsible':
+				$supported = strpos( $out->getHTML(), 'mw-collapsible' ) !== false;
+				break;
+			default:
+				throw new MWException( __METHOD__ . " Unknown skin feature $feature" );
+		}
+		$this->supportedFeatures[$feature] = $supported;
+		return $supported;
 	}
 
 	/**
@@ -213,13 +247,13 @@ abstract class Skin extends ContextSource {
 		];
 
 		// Preload jquery.tablesorter for mediawiki.page.ready
-		if ( strpos( $out->getHTML(), 'sortable' ) !== false ) {
+		if ( $this->supportsFeature( 'table-sorting', $out ) ) {
 			$modules['content'][] = 'jquery.tablesorter';
 			$modules['styles']['content'][] = 'jquery.tablesorter.styles';
 		}
 
 		// Preload jquery.makeCollapsible for mediawiki.page.ready
-		if ( strpos( $out->getHTML(), 'mw-collapsible' ) !== false ) {
+		if ( $this->supportsFeature( 'collapsible', $out ) ) {
 			$modules['content'][] = 'jquery.makeCollapsible';
 			$modules['styles']['content'][] = 'jquery.makeCollapsible.styles';
 		}
diff --git a/resources/src/mediawiki.page.ready/ready.js b/resources/src/mediawiki.page.ready/ready.js
index 9b1bb90b44..46e86fa36f 100644
--- a/resources/src/mediawiki.page.ready/ready.js
+++ b/resources/src/mediawiki.page.ready/ready.js
@@ -38,7 +38,7 @@ mw.hook( 'wikipage.content' ).add( function ( $content ) {
 	var $sortable, $collapsible;
 
 	$collapsible = $content.find( '.mw-collapsible' );
-	if ( $collapsible.length ) {
+	if ( $collapsible.length && mw.config.get( 'wgCollapsible' ) ) {
 		// Preloaded by Skin::getDefaultModules()
 		mw.loader.using( 'jquery.makeCollapsible', function () {
 			$collapsible.makeCollapsible();
@@ -46,7 +46,7 @@ mw.hook( 'wikipage.content' ).add( function ( $content ) {
 	}
 
 	$sortable = $content.find( 'table.sortable' );
-	if ( $sortable.length ) {
+	if ( $sortable.length && mw.config.get( 'wgSortable' ) ) {
 		// Preloaded by Skin::getDefaultModules()
 		mw.loader.using( 'jquery.tablesorter', function () {
 			$sortable.tablesorter();