1 files changed, 111 insertions, 0 deletions
diff --git a/www/wiki/resources/src/mediawiki/mediawiki.confirmCloseWindow.js b/www/wiki/resources/src/mediawiki/mediawiki.confirmCloseWindow.js
new file mode 100644
index 00000000..ee3bac24
--- /dev/null
+++ b/www/wiki/resources/src/mediawiki/mediawiki.confirmCloseWindow.js
@@ -0,0 +1,111 @@
+( function ( mw, $ ) {
+	/**
+	 * Prevent the closing of a window with a confirm message (the onbeforeunload event seems to
+	 * work in most browsers.)
+	 *
+	 * This supersedes any previous onbeforeunload handler. If there was a handler before, it is
+	 * restored when you execute the returned release() function.
+	 *
+	 *     var allowCloseWindow = mw.confirmCloseWindow();
+	 *     // ... do stuff that can't be interrupted ...
+	 *     allowCloseWindow.release();
+	 *
+	 * The second function returned is a trigger function to trigger the check and an alert
+	 * window manually, e.g.:
+	 *
+	 *     var allowCloseWindow = mw.confirmCloseWindow();
+	 *     // ... do stuff that can't be interrupted ...
+	 *     if ( allowCloseWindow.trigger() ) {
+	 *         // don't do anything (e.g. destroy the input field)
+	 *     } else {
+	 *         // do whatever you wanted to do
+	 *     }
+	 *
+	 * @method confirmCloseWindow
+	 * @member mw
+	 * @param {Object} [options]
+	 * @param {string} [options.namespace] Namespace for the event registration
+	 * @param {string} [options.message]
+	 * @param {string} options.message.return The string message to show in the confirm dialog.
+	 * @param {Function} [options.test]
+	 * @param {boolean} [options.test.return=true] Whether to show the dialog to the user.
+	 * @return {Object} An object of functions to work with this module
+	 */
+	mw.confirmCloseWindow = function ( options ) {
+		var savedUnloadHandler,
+			mainEventName = 'beforeunload',
+			showEventName = 'pageshow',
+			message;
+
+		options = $.extend( {
+			message: mw.message( 'mwe-prevent-close' ).text(),
+			test: function () { return true; }
+		}, options );
+
+		if ( options.namespace ) {
+			mainEventName += '.' + options.namespace;
+			showEventName += '.' + options.namespace;
+		}
+
+		if ( $.isFunction( options.message ) ) {
+			message = options.message();
+		} else {
+			message = options.message;
+		}
+
+		$( window ).on( mainEventName, function () {
+			if ( options.test() ) {
+				// remove the handler while the alert is showing - otherwise breaks caching in Firefox (3?).
+				// but if they continue working on this page, immediately re-register this handler
+				savedUnloadHandler = window.onbeforeunload;
+				window.onbeforeunload = null;
+				setTimeout( function () {
+					window.onbeforeunload = savedUnloadHandler;
+				}, 1 );
+
+				// show an alert with this message
+				return message;
+			}
+		} ).on( showEventName, function () {
+			// Re-add onbeforeunload handler
+			if ( !window.onbeforeunload && savedUnloadHandler ) {
+				window.onbeforeunload = savedUnloadHandler;
+			}
+		} );
+
+		/**
+		 * Return the object with functions to release and manually trigger the confirm alert
+		 *
+		 * @ignore
+		 */
+		return {
+			/**
+			 * Remove all event listeners and don't show an alert anymore, if the user wants to leave
+			 * the page.
+			 *
+			 * @ignore
+			 */
+			release: function () {
+				$( window ).off( mainEventName + ' ' + showEventName );
+			},
+			/**
+			 * Trigger the module's function manually: Check, if options.test() returns true and show
+			 * an alert to the user if he/she want to leave this page. Returns false, if options.test() returns
+			 * false or the user cancelled the alert window (~don't leave the page), true otherwise.
+			 *
+			 * @ignore
+			 * @return {boolean}
+			 */
+			trigger: function () {
+				// use confirm to show the message to the user (if options.text() is true)
+				// eslint-disable-next-line no-alert
+				if ( options.test() && !confirm( message ) ) {
+					// the user want to keep the actual page
+					return false;
+				}
+				// otherwise return true
+				return true;
+			}
+		};
+	};
+}( mediaWiki, jQuery ) );