title: Ionic 2 : How do you reinstantiate @ViewChild if you dismiss the view?
body: <p>I'm creating a chat experience and the page keeps up with the conversation by using the scrollToBottom method from Content on ionic-angular. If I start at the "PreChat.html" and go to "Chat.html" then I dismiss "Chat.html" to go back to "PreChat.html" and return again to "Chat.html" I get the following error: "Cannot read property 'scrollToBottom' of null". The experience should be able to be entered into at any time or repeatedly.</p>
  
  <p>PreChat.html:</p>
  
  <pre><code>&lt;ion-content&gt;
    &lt;button (click)="goToChat()" href="#"&gt;
      Chat
    &lt;/button&gt;
  &lt;/ion-content&gt;
  </code></pre>
  
  <p>PreChat.ts:</p>
  
  <pre><code>import { Component } from '@angular/core';
  import { ModalController } from 'ionic-angular';
  import { Chat } from '../chat';
  
  @Component({
    selector: 'preChat',
    templateUrl: 'preChat.html'
  })
  export class PreChat  {
     constructor(private modalCtrl: ModalController){}
  
     goToChat(): any {
      let profileModal = this.modalCtrl.create(Chat);
      profileModal.present();
    }
  }
  </code></pre>
  
  <p>Chat.html:</p>
  
  <pre><code>&lt;ion-content&gt;
    &lt;button ion-button="filter-button"(click)="dismiss()"&gt;
      &lt;ion-icon name="close"&gt;&lt;/ion-icon&gt;
    &lt;/button&gt;
    &lt;div *ngFor="let convo of conversationArray"&gt;
      &lt;div class="b-text"&gt;{{convo.speak}}&lt;/div&gt;
    &lt;/div&gt;
  &lt;/ion-content&gt;
  </code></pre>
  
  <p>Chat.ts:</p>
  
  <pre><code>import { Component, ViewChild } from '@angular/core';
  import { Content, Events, ViewController } from 'ionic-angular';
  
  @Component({
    templateUrl: 'Chat.html'
  })
  
  export class Chat {
    @ViewChild(Content) content: Content;
    conversationArray: any[] = [];
    constructor(private events: Events, private viewCtrl: ViewController){
      this.events.subscribe('conversation', convo =&gt; {
        this.conversationArray = convo;
        this.content.scrollToBottom();
      })
    }
    dismiss() {
     this.viewCtrl.dismiss(); 
   }
  }
  </code></pre>