text: import {NavController, Page} from 'ionic/ionic';
  import {DataService} from '../service/data';
  import {Action} from '../action/action';
  import {Media} from '../media/media';
  import {Home} from '../home/home';
  import {News} from '../news/news';
  
  @Page({
    templateUrl: 'app/tabs/tabs.html',
    providers: [DataService]
  })
  export class Tabs {
    constructor(nav: NavController, dataService: DataService) {
      // set the root pages for each tab
      this.tab1Root = Home;
      this.tab2Root = News;
      this.tab3Root = Media;
      this.tab4Root = Action;
  
      // retrieve the conference data
      dataService.retrieveData();
    }
  }
  