title: Angular 6 Date picker(disabled input field) is not binding to form object
body: <blockquote>
    <p>I am new at angular. I am using <strong>angular material(7.0.2)</strong>. I tried the below form has <strong>date picker</strong> with <strong>disabled</strong> input. On submitting <strong>date</strong> is not appearing in <strong>f.value(object of form)</strong>. If I <strong>remove disabled</strong> from an input field then it works perfectly. I don't know it is due to disabled or something else is the reason. In short, due to disabled it does not able to return form object.</p>
  </blockquote>
  
  <pre><code>&lt;form (ngSubmit)="AddEvent(f)" #f="ngForm"&gt;
      &lt;mat-form-field&gt;
        &lt;input matInput ngModel name="date" [matDatepicker]="picker"  disabled required&gt;
        &lt;mat-datepicker-toggle matSuffix [for]="picker"&gt;&lt;/mat-datepicker-toggle&gt;
        &lt;mat-datepicker disabled="false" touchUi #picker&gt;&lt;/mat-datepicker&gt;
      &lt;/mat-form-field&gt;
    &lt;/form&gt;
  </code></pre>
  
  <blockquote>
    <p>Here is a code of TS file</p>
  </blockquote>
  
  <pre><code>export class CreateEventComponent implements OnInit {
  
    isLogin:boolean = false;
    constructor() { }
  
    ngOnInit() {
    }
  
    AddEvent(f)
    {
      f.value.date =f.value.date.toDateString();
      console.log(f.value);
  
    }
  
  }
  </code></pre>
  
  <blockquote>
    <p>Output:</p>
  </blockquote>
  
  <pre><code>Null object
  </code></pre>