refs #3332 fixing regression related to using ajaxHelper in transitio…

…ns: use regular transitions callback when PHP throws an exception (e.g. NoDataForAction) to let transitions handle the error and show a message in the popover.

plugins/Transitions/templates/transitions.js

@@ -1408,6 +1408,7 @@ Piwik_Transitions_Ajax.prototype.callApi = function(method, params, callback) {
 
     var ajaxRequest = new ajaxHelper();
     ajaxRequest.addParams(params, 'get');
+	ajaxRequest.useCallbackInCaseOfError();
     ajaxRequest.setCallback(
         function (result) {
             if (typeof result.result != 'undefined' && result.result == 'error') {

themes/default/ajaxHelper.js

@@ -66,6 +66,12 @@ function ajaxHelper() {
      */
     this.callback =       function () {};
 
+	/**
+	 * Use this.callback if an error is returned
+	 * @type {Boolean}
+	 */
+	this.useRegularCallbackInCaseOfError = false;
+
     /**
      * Callback function to be executed on error
      */
@@ -156,6 +162,16 @@ function ajaxHelper() {
         this.callback = callback;
     };
 
+	/**
+	 * Set that the callback passed to setCallback() should be used if an application error (i.e. an
+	 * Exception in PHP) is returned.
+	 * 
+	 * @param {void}
+	 */
+	this.useCallbackInCaseOfError = function () {
+		this.useRegularCallbackInCaseOfError = true;
+	};
+
     /**
      * Set callback to redirect on success handler
      * &update=1(+x) will be appended to the current url
@@ -301,7 +317,7 @@ function ajaxHelper() {
                     $(that.loadingElement).hide();
                 }
 
-                if (response && response.result == 'error') {
+                if (response && response.result == 'error' && !that.useRegularCallbackInCaseOfError) {
                     if ($(that.errorElement).length && response.message) {
                         $(that.errorElement).html(response.message).fadeIn();
                         piwikHelper.lazyScrollTo(that.errorElement, 250);