title: Components not showing for ngIf
body: <p>I created a sample app in Angular 5. I have two components called <strong>app-parent</strong> and <strong>app-child</strong> and have a sample text in each. I have a variable in my App component and I need to show above components each at a time triggered by the value of variable.</p>
  
  <p>This is the code.</p>
  
  <p>App.component.ts</p>
  
  <pre><code>export class AppComponent {
    val:string;
  }
  </code></pre>
  
  <p>App.component.html:</p>
  
  <pre><code>&lt;div *ngIf="!val; then r; else s"&gt;
      &lt;ng-template #r&gt;
          &lt;app-parent&gt;&lt;/app-parent&gt;
      &lt;/ng-template&gt;
      &lt;ng-template #s&gt;
          &lt;app-child&gt;&lt;/app-child&gt;
      &lt;/ng-template&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I expect to <code>&lt;app-parent&gt;</code> be appeared, but in the result, nothing is appearing. What is the problem here?</p>