title: Cannot get active element form template
body: <p>I've a simple component as following where I am trying to get reference to the active element from it's template.</p>
  
  <pre><code>export class SidebarComponent {
    @ViewChildren(RouterLinkActive) linkItems: QueryList&lt;RouterLinkActive&gt;;
  
    ngAfterViewInit() {
      let activeLink = this.linkItems.find(item =&gt; item.isActive);
  
      console.log('Active link is');
      console.log(activeLink); //this is undefined
    }
  
  }
  </code></pre>
  
  <p>And here is a simple template for above component.</p>
  
  <pre><code>&lt;ul&gt;
    &lt;li&gt;
      &lt;a [routerLink]="['/app/link1']" routerLinkActive="active"&gt; Link 1&lt;/a&gt;
    &lt;/li&gt;
    &lt;li&gt;
      &lt;a [routerLink]="['/app/link2']" routerLinkActive="active"&gt; Link 2&lt;/a&gt;
    &lt;/li&gt;
  &lt;/ul&gt;
  </code></pre>
  
  <p>The problem is I am not getting the active element from the template even though the style is applied to the element with <code>active</code> class. The same code worked with angular v2 but breaked in angular v4. What should I do to get the active element in angular v4?</p>