feature(events): add events api to angular package

packages/angular/src/index.ts

@@ -7,6 +7,7 @@ export { IonNavDelegate } from './components/ion-nav';
 export { ActionSheetController, ActionSheetProxy } from './providers/action-sheet-controller';
 export { AlertController, AlertProxy } from './providers/alert-controller';
 export { App } from './providers/app';
+export { Events } from './providers/events';
 export { LoadingController, LoadingProxy } from './providers/loading-controller';
 export { ModalController, ModalProxy } from './providers/modal-controller';
 export { NavController } from './providers/nav-controller';

packages/angular/src/module.ts

@@ -19,6 +19,7 @@ import { IonNavDelegate } from './components/ion-nav';
 import { ActionSheetController } from './providers/action-sheet-controller';
 import { AlertController } from './providers/alert-controller';
 import { AngularComponentMounter } from './providers/angular-component-mounter';
+import { Events } from './providers/events';
 import { LoadingController } from './providers/loading-controller';
 import { ModalController } from './providers/modal-controller';
 import { PopoverController } from './providers/popover-controller';
@@ -56,6 +57,7 @@ export class IonicAngularModule {
         AlertController,
         ActionSheetController,
         AngularComponentMounter,
+        Events,
         LoadingController,
         ModalController,
         PopoverController,

packages/angular/src/providers/events.ts

@@ -0,0 +1,33 @@
+import { Injectable } from '@angular/core';
+
+import { ensureElementInBody, hydrateElement } from '../util/util';
+
+let hydratedElement: HTMLIonEventsElement = null;
+
+@Injectable()
+export class Events {
+
+  publish(topic: string, event?: any): Promise<any> {
+    return getElement().then((element: HTMLIonEventsElement) => {
+      return element.publish(topic, event);
+    });
+  }
+
+  subscribe(topic: string, handler: (event?: any) => void) {
+    return getElement().then((element: HTMLIonEventsElement) => {
+      return element.subscribe(topic, handler);
+    });
+  }
+}
+function getElement(): Promise<HTMLIonEventsElement> {
+  if (hydratedElement) {
+    return Promise.resolve(hydratedElement);
+  }
+  const element = ensureElementInBody(ELEMENT_NAME);
+  return hydrateElement(element).then((element: HTMLIonEventsElement) => {
+    hydratedElement = element;
+    return element;
+  });
+}
+
+const ELEMENT_NAME = 'ion-events';