title: How to get reference to unknown children elements using @ViewChildren
body: <p>I'm using a third party library that lets me create tabsets. This is the code I'm using to create a simple tabset</p>
  
  <pre><code>&lt;clr-tabs           
     (clrTabsCurrentTabContentChanged)="onTabContentActivated($event)" &gt;
  
    &lt;clr-tab-link&gt;Firewall&lt;/clr-tab-link&gt;
    &lt;clr-tab-link&gt;DHCP&lt;/clr-tab-link&gt;
  
    &lt;clr-tab-content&gt;
        &lt;vcd-firewall-tab&gt;&lt;/vcd-firewall-tab&gt;
    &lt;/clr-tab-content&gt;
  
    &lt;clr-tab-content&gt;
       &lt;vcd-dhcp-tab&gt;&lt;/vcd-dhcp-tab&gt;
    &lt;/clr-tab-content&gt;
  &lt;/clr-tabs&gt;
  </code></pre>
  
  <p>I have hooked up an event that will tell me when a tab was selected, and I would like to call the <code>loadData()</code>method on <code>&lt;vcd-firewall-tab&gt;</code> and <code>&lt;vcd-dhcp-tab&gt;</code>.</p>
  
  <p>The <code>clrTabsCurrentTabContentChanged</code> will give me a reference to the <code>clr-tab-content</code> that was selected but I would like to access its first child and call <code>loadData()</code> to implement lazy loading.</p>
  
  <p>I think I can use <code>@QueryChildren</code> annotation, except that I have to specify the type of element to query for. The problem is that in this case, I don't know the type, it could be <code>&lt;vcd-firewall-tab&gt;</code>, <code>&lt;vcd-dhcp-tab&gt;</code> or the many other tabs that we have and I don't want to add custom code every time I add a new tab.</p>
  
  <p>I was hoping to be able to do something like this from my event handler (but that doesn't exist</p>
  
  <pre><code>onTabContentActivated(tabContent: TabContent){
      (tabContent.query(':first-child') as CanLoadData).loadData();
  }
  </code></pre>
  
  <p>I'm open to any suggestions, I thought maybe I could match the index of the tab to something like <code>@QueryChildren('clr-tab-content &gt; *')</code>, assuming there's only one child under each tab.</p>