Add CustomEvent polyfill

README.md

@@ -99,7 +99,8 @@ DOM
     * `EventTarget.removeEventListener(event, handler)` - for IE8+
   * Event: `target`, `currentTarget`, `eventPhase`, `bubbles`, `cancelable`, `timeStamp`, `defaultPrevented`, `stopPropagation()`, `cancelBubble()`
 * Non-standard Event helpers for IE7- - adapted from
-[QuirksMode](http://www.quirksmode.org/blog/archives/2005/10/_and_the_winner_1.html)
+* [Custom Events](https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent)
+* [QuirksMode](http://www.quirksmode.org/blog/archives/2005/10/_and_the_winner_1.html)
   * `window.addEvent(EventTarget, event, handler)`
   * `window.removeEvent(EventTarget, event, handler)`
 * [DOMTokenList](https://dom.spec.whatwg.org/#interface-domtokenlist) - `classList`[spec](https://dom.spec.whatwg.org/#dom-element-classlist), `relList`[spec](https://html.spec.whatwg.org/multipage/semantics.html#the-link-element)

dom.js

@@ -213,6 +213,23 @@
     });
   }());
 
+  // CustomEvent
+  // https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent
+  // Needed for: IE
+  (function () {
+    if ('CustomEvent' in global) {
+      if ( typeof global.CustomEvent === "function" ) return false;
+    }
+    function CustomEvent ( event, params ) {
+      params = params || { bubbles: false, cancelable: false, detail: undefined };
+      var evt = document.createEvent( 'CustomEvent' );
+      evt.initCustomEvent( event, params.bubbles, params.cancelable, params.detail );
+      return evt;
+    }
+    CustomEvent.prototype = window.Event.prototype;
+    global.CustomEvent = CustomEvent;
+  })();
+
   // Shim for DOM Events for IE7-
   // http://www.quirksmode.org/blog/archives/2005/10/_and_the_winner_1.html
   // Use addEvent(object, event, handler) instead of object.addEventListener(event, handler)

tests/dom.html

@@ -43,6 +43,8 @@
 
 </div>
 
+<div id="customev"></div>
+
 <script type="text/javascript" src="../es5.js"></script>
 <script type="text/javascript" src="../dom.js"></script>
 

tests/dom_tests.js

@@ -469,3 +469,14 @@ QUnit.test('Mixin ChildNode: before, after, replaceWith - Behavior when nodes co
   s3.after(s4, s3, s2);
   assert.equal(div.textContent, '1432', 'after should work when successor is removed');
 });
+
+QUnit.test('CustomEvent: addEventListener and dispatchEvent', function(assert) {
+  var done = assert.async();
+  var div = document.getElementById('customev');
+  div.addEventListener('customevent', function(e) {
+    assert.equal(e.detail.teststring, "test string");
+    done();
+  });
+  assert.ok(CustomEvent instanceof Function);
+  div.dispatchEvent(new CustomEvent("customevent", { detail: { teststring: "test string" } }));
+});