title: Custom component FormControl breaking if reinitializing FormGroup from parent
body: <p>I got a problem when reinitializing  formGroup from parent component that is used in my custom component. Error that i get is:</p>
  <blockquote>
  <p>There is no FormControl instance attached to form control element with
  name: 'selectedCompany'</p>
  </blockquote>
  <p><strong>HTML</strong>:</p>
  <pre class="lang-html prettyprint-override"><code>&lt;form [formGroup]=&quot;addForm&quot;&gt;
       ...
       &lt;my-custom-component formControlName=&quot;selectedCompany&quot;&gt;&lt;/my-custom-component&gt;
       ...
  &lt;/form
  </code></pre>
  <p><code>&lt;my-custom-component&gt;</code> is created according to valid way of creating custom formControl component: <a href="https://blog.thoughtram.io/angular/2016/07/27/custom-form-controls-in-angular-2.html#implementing-controlvalueaccessor" rel="nofollow noreferrer">https://blog.thoughtram.io/angular/2016/07/27/custom-form-controls-in-angular-2.html#implementing-controlvalueaccessor</a></p>
  <p><strong>Component</strong></p>
  <p>This is code that initializes formGroup variable <code>addForm</code>:</p>
  <pre class="lang-js prettyprint-override"><code>let formTemp: any = {
      selectedCompany: new FormControl(null, [Validators.required]),
  }
  
  this.addForm = this._formBuilder.group(formTemp);
  </code></pre>
  <p>First time <code>addForm</code> is initialized all is good. But when i reopen modal where form is located, and same component code is executed, above mentioned error occurs.</p>