title: How to notify parent about change in child component?
body: <p>I have a child component with this template:</p>
  
  <pre><code>&lt;p *ngIf="user != null" &gt;
      Id: {{user.id}}&lt;br&gt;
      Name: {{user.firstName}} {{user.lastName}}&lt;br&gt;
      Nick: {{user.nickname}}&lt;br&gt;
      Gender: {{user.gender}}&lt;br&gt;
      Birthday: {{user.birthday}}&lt;br&gt;
      Last login: {{user.lastUpdateDate}}&lt;br&gt;
      Registered: {{user.registrationDate}}&lt;br&gt;
  &lt;/p&gt;
  </code></pre>
  
  <p>I get user from server using http request, so when data is loaded, user is shown.</p>
  
  <p>How can I notify parent component that data was loaded and shown?</p>