From: Timo Tijhof <krinklemail@gmail.com>
Date: Fri, 27 Mar 2015 23:55:20 +0000 (+0000)
Subject: mw.track: Implement trackUnsubscribe
X-Git-Tag: 1.31.0-rc.0~11510^2
X-Git-Url: http://git.cyclocoop.org//%27%40script%40/%27?a=commitdiff_plain;h=0e62e43941bc82a398b7cdf62795811a5e87d8fe;p=lhc%2Fweb%2Fwiklou.git

mw.track: Implement trackUnsubscribe

Bug: T93986
Change-Id: I38219319cb7963f1f19ee81857dd084709fb6be1
---

diff --git a/resources/src/mediawiki/mediawiki.js b/resources/src/mediawiki/mediawiki.js
index 237157c75f..e556ed8892 100644
--- a/resources/src/mediawiki/mediawiki.js
+++ b/resources/src/mediawiki/mediawiki.js
@@ -14,6 +14,7 @@
 		hasOwn = Object.prototype.hasOwnProperty,
 		slice = Array.prototype.slice,
 		trackCallbacks = $.Callbacks( 'memory' ),
+		trackHandlers = [],
 		trackQueue = [];
 
 	/**
@@ -461,8 +462,7 @@
 		 */
 		trackSubscribe: function ( topic, callback ) {
 			var seen = 0;
-
-			trackCallbacks.add( function ( trackQueue ) {
+			function handler( trackQueue ) {
 				var event;
 				for ( ; seen < trackQueue.length; seen++ ) {
 					event = trackQueue[ seen ];
@@ -470,6 +470,26 @@
 						callback.call( event, event.topic, event.data );
 					}
 				}
+			}
+
+			trackHandlers.push( [ handler, callback ] );
+
+			trackCallbacks.add( handler );
+		},
+
+		/**
+		 * Stop handling events for a particular handler
+		 *
+		 * @param {Function} callback
+		 */
+		trackUnsubscribe: function ( callback ) {
+			trackHandlers = $.grep( trackHandlers, function ( fns ) {
+				if ( fns[1] === callback ) {
+					trackCallbacks.remove( fns[0] );
+					// Ensure the tuple is removed to avoid holding on to closures
+					return false;
+				}
+				return true;
 			} );
 		},
 
diff --git a/tests/qunit/suites/resources/mediawiki/mediawiki.track.test.js b/tests/qunit/suites/resources/mediawiki/mediawiki.track.test.js
index cdb2624404..5329be6a9c 100644
--- a/tests/qunit/suites/resources/mediawiki/mediawiki.track.test.js
+++ b/tests/qunit/suites/resources/mediawiki/mediawiki.track.test.js
@@ -39,4 +39,22 @@
 			assert.assertTrue( this.timeStamp >= now, 'thisValue has sane timestamp' );
 		} );
 	} );
+
+	QUnit.test( 'trackUnsubscribe', 1, function ( assert ) {
+		var sequence = [];
+		function unsubber( topic, data ) {
+			sequence.push( [ topic, data ] );
+		}
+
+		mw.track( 'unsub', { key: 1 } );
+		mw.trackSubscribe( 'unsub', unsubber );
+		mw.track( 'unsub', { key: 2 } );
+		mw.trackUnsubscribe( unsubber );
+		mw.track( 'unsub', { key: 3 } );
+
+		assert.deepEqual( sequence, [
+			[ 'unsub', { key: 1 } ],
+			[ 'unsub', { key: 2 } ]
+		], 'Stop when unsubscribing' );
+	} );
 }( mediaWiki ) );