title: How to read the property of a application selector at the time of initialization?
body: <p>This is my start page, it is rendered on the backend (instead of <code>'propval'</code> there will be a variable containing the json-configuration):</p>
  
  <pre><code>&lt;%- include('template/head'); %&gt;
  &lt;application [userdata]='"propval"'&gt;
      Loading...
  &lt;/application&gt;
  &lt;%- include('template/foot'); %&gt;
  </code></pre>
  
  <p>This is my component that handles the 'application' selector:</p>
  
  <pre><code>@Component({
      moduleId: module.id,
      selector: 'application',
      templateUrl: './app.component.html',
      providers:[
          ProgressBar
      ]
  })
  export class AppComponent implements OnInit {
  
      public userdata;
  
      constructor(public progressBar :ProgressBar, private router: Router) {
          console.log("constructor",this.userdata);
      }
  
      public async ngOnInit() {
          console.log("ngOnInit",this.userdata);
      }
  
  }
  </code></pre>
  
  <p>As a result, in the console I get:</p>
  
  <pre><code>constructor undefined
  ngOnInit undefined
  </code></pre>
  
  <p>How to read <code>userdata</code> property? Perhaps this is not will done in <code>AppComponent</code>, since <code>application</code> selector is not rendered inside the <code>app.component.html</code>. <code>application</code> selector rendered on the backend.</p>