bootstrap.ts

import { bootstrap } from '@angular/platform-browser-dynamic';
import { ComponentRef, NgZone } from '@angular/core';

import { AppRoot, UserComponent } from '../components/app/app';
import { nativeRaf } from '../util/dom';
import { ionicProviders } from './providers';
import { Platform } from '../platform/platform';
import { TapClick } from '../components/tap-click/tap-click';
const _reflect: any = Reflect;


/**
 * @name ionicBootstrap
 * @description
 * `ionicBootstrap` allows you to bootstrap your entire application. Similar to Angular's `bootstrap`, `ionicBootstrap`
 * takes a root component in order to start the app. You can pass along any providers that you may want to inject into your
 * app as an array for the second argument. You can also pass a config object as the third argument to configure your app's settings.
 *
 * @usage
 *
 * ```ts
 * import { ionicBootstrap } from 'ionic-angular';
 * import { Component } from '@angular/core';
 *
 * @Component({
 *   templateUrl: 'build/app.html',
 * })
 * export class MyClass{}
 *
 * ionicBootstrap(MyClass, null, {tabsPlacement: 'bottom'})
 * ```
 */
export function ionicBootstrap(appRootComponent: any, customProviders?: Array<any>, config?: any) {
  // get all Ionic Providers
  let providers = ionicProviders(customProviders, config);
  providers.push({provide: UserComponent, useValue: appRootComponent});

  return new Promise((resolve) => {
    cssReady(() => {
      // call angular bootstrap
      bootstrap(AppRoot, providers).then(ngComponentRef => {
        // ionic app has finished bootstrapping
        ionicPostBootstrap(ngComponentRef);
        resolve(ngComponentRef);
      });
    });
  });
}


/**
 * @private
 */
export function ionicPostBootstrap(ngComponentRef: ComponentRef<any>) {
  // prepare platform ready
  let platform: Platform = ngComponentRef.injector.get(Platform);
  platform.setZone(ngComponentRef.injector.get(NgZone));
  platform.prepareReady();
  ngComponentRef.injector.get(TapClick);

  return ngComponentRef;
}

let cssLoadAttempt = 0;
function cssReady(done: Function) {
  let appEle = <HTMLElement>document.body.querySelector('ion-app');

  if (!appEle || appEle.clientHeight > 0 || cssLoadAttempt > 300) {
    done();

  } else {
    nativeRaf(() => {
      cssLoadAttempt++;
      cssReady(done);
    });
  }
}


/**
 * @private
 */
export function addSelector(type: any, selector: string) {
  if (type) {
    let annotations = _reflect.getMetadata('annotations', type);
    if (annotations && !annotations[0].selector) {
      annotations[0].selector = selector;
      _reflect.defineMetadata('annotations', annotations, type);
    }
  }
}