Fixes #1149: Filter out already included javascript files requested via ajax.

framework/yii/assets/yii.js

@@ -43,6 +43,11 @@
  */
 yii = (function ($) {
 	var pub = {
+		/**
+		 * List of scripts that can be loaded multiple times via AJAX requests. Each script can be represented
+		 * as either an absolute URL or a relative one.
+		 */
+		reloadableScripts: [],
 		/**
 		 * The selector for clickable elements that need to support confirmation and form submission.
 		 */
@@ -161,23 +166,34 @@ yii = (function ($) {
 		},
 
 		init: function () {
-			var $document = $(document);
+			initCsrfHandler();
+			initRedirectHandler();
+			initScriptFilter();
+			initDataMethods();
+		}
+	};
 
+	function initRedirectHandler() {
+		// handle AJAX redirection
+		$(document).ajaxComplete(function (event, xhr, settings) {
+			var url = xhr.getResponseHeader('X-Redirect');
+			if (url) {
+				window.location = url;
+			}
+		});
+	}
+
+	function initCsrfHandler() {
 		// automatically send CSRF token for all AJAX requests
 		$.ajaxPrefilter(function (options, originalOptions, xhr) {
 			if (!options.crossDomain && pub.getCsrfVar()) {
 				xhr.setRequestHeader('X-CSRF-Token', pub.getCsrfToken());
 			}
 		});
-
-			// handle AJAX redirection
-			$document.ajaxComplete(function (event, xhr, settings) {
-				var url = xhr.getResponseHeader('X-Redirect');
-				if (url) {
-					window.location = url;
 	}
-			});
 
+	function initDataMethods() {
+		var $document = $(document);
 		// handle data-confirm and data-method for clickable elements
 		$document.on('click.yii', pub.clickableSelector, function (event) {
 			var $this = $(this);
@@ -200,7 +216,29 @@ yii = (function ($) {
 			}
 		});
 	}
-	};
+
+	function initScriptFilter() {
+		var hostInfo = location.protocol + '//' + location.host;
+		var loadedScripts = $('script').filter(function () {
+			return this.src;
+		}).map(function () {
+			return this.src.charAt(0) === '/' ? hostInfo + this.src : this.src;
+		}).toArray();
+		$.ajaxPrefilter('script', function (options, originalOptions, xhr) {
+			var url = options.url.charAt(0) === '/' ? hostInfo + options.url : options.url;
+			if (loadedScripts.indexOf(url) < 0) {
+				loadedScripts.push(url);
+			} else {
+				var found = pub.reloadableScripts.map(function () {
+					return this.charAt(0) === '/' ? hostInfo + this : this;
+				}).indexOf(url) >= 0;
+				if (!found) {
+					xhr.abort();
+				}
+			}
+		});
+	}
+
 	return pub;
 })(jQuery);