title: Access DOM element outside of Angular root component
body: <p>Consider this index.html:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div id="test-case"&gt;
    Hello
    &lt;button type="button"&gt;Press me&lt;/button&gt;
  &lt;/div&gt;
  &lt;app&gt; &lt;/app&gt;
  </code></pre>
  
  <p>where <strong>app</strong> is the <code>root component</code>. Is it possible to access <code>test-case</code> element <strong>from inside the app component</strong> and manipulate <code>button click event</code> via Angular methods? I could use vanilla Javascript, but is there an Angular way of doing that?</p>