title: Set focus to element of nested component in Angular 4
body: <p>In angular 4, I have a component nested inside of another. The inner or the child component contains: a button, an input and a drop down list.<br>
  On the parent page, when I click on the button, both the input and the drop-down are displayed.</p>
  
  <p>What is a good way to set focus of the input when clicking the button?</p>
  
  <p>What I tried so far:<br>
  In the child component, I added an id on the input: <code>&lt;input #inputId ... &gt;</code>, then in the same method triggered when the button is pressed, in the child component, I added:</p>
  
  <pre><code>$('#inputId').focus();
  </code></pre>
  
  <p>But this has no effect...<br>
  Any suggestions? </p>