title: Using Ionic2 toggle with firebase
body: <p>I have list of users, and I want to enable/disable them.</p>
  
  <p>I have firebase list binded to ion-list </p>
  
  <pre><code>  constructor(public navCtrl: NavController,
                private af: AngularFire,
                public cartService: CartService) {
      this.users = af.database.list('/users')
    }
  
    toggleUserStatus(user) {
      this.users.update(user.$key, {isActive: user.isActive})
        .then(_ =&gt; this.cartService.showToast('User ' + ((user.isActive) ? 'Enabled' : 'Disabled')))
        .catch(err =&gt; this.cartService.showToast(err));
    }
  </code></pre>
  
  <p>template;</p>
  
  <pre><code>&lt;div *ngFor="let user of users|async"&gt;
    &lt;ion-item padding&gt;
      &lt;ion-label&gt;{{user.fullName}}&lt;/ion-label&gt;
      &lt;ion-toggle tappable (ionChange)="toggleUserStatus(user)" [(ngModel)]="user.isActive"&gt;&lt;/ion-toggle&gt;
    &lt;/ion-item&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>However it doesn't work. Its toggling again and again again.</p>
  
  <p>How can I make this work?</p>
  
  <p>Thank you.</p>