fix(jqLite): allow triggerHandler() to accept custom event

petebacondarwin · petebacondarwin · commit 01d81cdab3db · 2014-08-10T20:26:32.000+01:00
In some scenarios you want to be able to specify properties on the event that is passed to the event handler. JQuery does this by overloading the first parameter (`eventName`). If it is an object with a `type` property then we assume that it must be a custom event. In this case the custom event must provide the `type` property which is the name of the event to be triggered. `triggerHandler` will continue to provide dummy default functions for `preventDefault()`, `isDefaultPrevented()` and `stopPropagation()` but you may override these with your own versions in your custom object if you wish. In addition the commit provides some performance and memory usage improvements by only creating objects and doing work that is necessary. This commit also renames the parameters inline with jQuery. Closes angular#8469
diff --git a/src/jqLite.js b/src/jqLite.js
@@ -947,26 +947,37 @@ forEach({
 
   clone: jqLiteClone,
 
-  triggerHandler: function(element, eventName, eventData) {
-    // Copy event handlers in case event handlers array is modified during execution.
-    var eventFns = (jqLiteExpandoStore(element, 'events') || {})[eventName],
-        eventFnsCopy = shallowCopy(eventFns || []);
-
-    eventData = eventData || [];
-
-    var event = [{
-      preventDefault: function() {
-        this.defaultPrevented = true;
-      },
-      isDefaultPrevented: function() {
-        return this.defaultPrevented === true;
-      },
-      stopPropagation: noop
-    }];
-
-    forEach(eventFnsCopy, function(fn) {
-      fn.apply(element, event.concat(eventData));
-    });
+  triggerHandler: function(element, event, extraParameters) {
+
+    var dummyEvent, eventFnsCopy, handlerArgs;
+    var eventName = event.type || event;
+    var eventFns = (jqLiteExpandoStore(element, 'events') || {})[eventName];
+
+    if (eventFns) {
+
+      // Create a dummy event to pass to the handlers
+      dummyEvent = {
+        preventDefault: function() { this.defaultPrevented = true; },
+        isDefaultPrevented: function() { return this.defaultPrevented === true; },
+        stopPropagation: noop,
+        type: eventName,
+        target: element
+      };
+
+      // If a custom event was provided then extend our dummy event with it
+      if (event.type) {
+        dummyEvent = extend(dummyEvent, event);
+      }
+
+      // Copy event handlers in case event handlers array is modified during execution.
+      eventFnsCopy = shallowCopy(eventFns);
+      handlerArgs = extraParameters ? [dummyEvent].concat(extraParameters) : [dummyEvent];
+
+      forEach(eventFnsCopy, function(fn) {
+        fn.apply(element, handlerArgs);
+      });
+
+    }
   }
 }, function(fn, name){
   /**
diff --git a/test/jqLiteSpec.js b/test/jqLiteSpec.js
@@ -1718,9 +1718,11 @@ describe('jqLite', function() {
       element.triggerHandler('click');
       event = pokeSpy.mostRecentCall.args[0];
       expect(event.preventDefault).toBeDefined();
+      expect(event.target).toEqual(element[0]);
+      expect(event.type).toEqual('click');
     });
 
-    it('should pass data as an additional argument', function() {
+    it('should pass extra parameters as an additional argument', function() {
       var element = jqLite('<a>poke</a>'),
           pokeSpy = jasmine.createSpy('poke'),
           data;
@@ -1765,6 +1767,24 @@ describe('jqLite', function() {
       expect(clickOnceSpy).toHaveBeenCalledOnce();
       expect(clickSpy.callCount).toBe(2);
     });
+
+    it("should accept a custom event instead of eventName", function() {
+      var element = jqLite('<a>poke</a>'),
+          pokeSpy = jasmine.createSpy('poke'),
+          customEvent = {
+            type: 'click',
+            someProp: 'someValue'
+          },
+          actualEvent;
+
+      element.on('click', pokeSpy);
+      element.triggerHandler(customEvent);
+      actualEvent = pokeSpy.mostRecentCall.args[0];
+      expect(actualEvent.preventDefault).toBeDefined();
+      expect(actualEvent.someProp).toEqual('someValue');
+      expect(actualEvent.target).toEqual(element[0]);
+      expect(actualEvent.type).toEqual('click');
+    });
   });
 
 
