title: Why does Angular 2 not detect change?
body: <p>I am having a similar code and error as <a href="https://stackoverflow.com/questions/34364880/expression-has-changed-after-it-was-checked">Expression ___ has changed after it was checked</a> where I am changing a variable value in <code>ngAfterViewInit()</code>.
  <br><br>One of the answers <a href="https://stackoverflow.com/a/35243106/1460595">https://stackoverflow.com/a/35243106/1460595</a> suggests to manually trigger change detection by calling <code>detectChanges()</code> method of <code>ChangeDetectorRef</code>, which works.<br></p>
  
  <p>But why do we have to handle change manually when Angular 2 should be handling the change? <br>Is there some relationship between lifecycle hooks and change detection? </p>