title: Ionic 2 ion tabs are not updated when nav push to tab page
body: <p>Page A shows some information obtained from a database (Table A). There a button in Page A, when clicked will nav push to another page with a form (Form Page). When I submitted the form, a PHP function will run and insert new record into Table A. After the PHP function is executed successfully, it will redirect the me back to the root of the Tab Page (which is the Home Page). When I try to redirect back to Page A, by clicking the ion tab button, Page A does not show any updates that I made. I want page A to fetch data again from the database (Table A)</p>
  
  <p>I've checked my database, and the table is updated when the form is submitted</p>
  
  <p>formPage.ts</p>
  
  <pre><code>    // This function updates Table A
      this.http.get(url).map(res =&gt; res.json()).subscribe(data =&gt; {
        if( data['success'] == true) {
            this.navCtrl.push(TabPage, { userId: this.userId });
        };
      }, 
          err =&gt; { console.log(err); }
      );
  </code></pre>
  
  <p>tabPage.ts</p>
  
  <pre><code>  constructor(public navCtrl: NavController, public navParams: NavParams){
        this.navParams = navParams;
        // I used data because I submit login data from login page
        // userId will get data from both login page and from formPage
        this.userId = this.navParams.data;
     }
  </code></pre>
  
  <p>tabPage.html</p>
  
  <pre><code>    &lt;ion-tabs&gt;
          &lt;ion-tab [root]="pageA" [rootParams]="userId"&gt;&lt;/ion-tab&gt;
      &lt;/ion-tabs&gt;
  </code></pre>
  
  <p>Page A.ts</p>
  
  <pre><code>    constructor(public navCtrl: NavController, public navParams: NavParams, private HttpServices: HttpServices, private App: App, public loadingController: LoadingController) {
          this.userId = this.navParams.get('userId');
          this.HttpServices.fetchFromTabelA(this.userId).subscribe(data =&gt; {
              this.data = data;
          },
              err =&gt; { console.error(err); }
          );
      }
  </code></pre>
  
  <p>tl;dr
      - A page does not show any update made to the database</p>