Adding custom event support

src/utils/custom-event.js

@@ -0,0 +1,38 @@
+const NativeCustomEvent = window.CustomEvent;
+
+/**
+ * Check for the usage of native support for CustomEvents which is lacking
+ * completely on IE.
+ * @return {boolean} Whether it can be used or not.
+ */
+function canIuseNativeCustom () {
+  try {
+    const p = new NativeCustomEvent('t', { detail: { a: 'b' } });
+    return  't' === p.type && 'b' === p.detail.a;
+  } catch (e) {
+  }
+  return false;
+}
+
+/**
+ * Lousy polyfill for the Custom Event constructor for IE.
+ * @param {!string} type The type of the event.
+ * @param {?Object} params Additional information for the event.
+ * @return {Event}
+ * @constructor
+ */
+const IECustomEvent = function CustomEvent(type, params) {
+  const e = document.createEvent('CustomEvent');
+
+  if (params) {
+    e.initCustomEvent(type, params.bubbles, params.cancelable, params.detail);
+  } else {
+    e.initCustomEvent(type, false, false, undefined);
+  }
+
+  return e;
+};
+
+const WSCustomEvent = canIuseNativeCustom() ? NativeCustomEvent : IECustomEvent;
+
+export default WSCustomEvent;

src/utils/dom.js

@@ -1,3 +1,6 @@
+import WSCustomEvent from './custom-event';
+
+
 /**
  * Static class for DOM helper.
  */
@@ -54,4 +57,16 @@ export default class DOM {
   static unlockScroll() {
     document.documentElement.style.overflow = 'auto';
   }
+
+  /**
+   * Fires a custom event on the given target.
+   * @param {Element} target The target of the event.
+   * @param {string} eventType The event type.
+   * @param {Object} eventInfo Optional parameter to provide additional data
+   * to the event.
+   */
+  static fireEvent(target, eventType, eventInfo = { detail: '' }) {
+    const event = new WSCustomEvent(eventType, eventInfo);
+    target.dispatchEvent(event);
+  }
 }