title: AngularJS ngIf object has attribute
body: <p>I have an array like this:</p>
  
  <pre><code>{
      selector: "departureDate",
      selectorName: "Departure Date",
      constraints: ["GreaterThan", "LessThan", "Equals", "NotEquals"],
      valueType: "Date"
  }, {
      selector: "arrivalDay",
      selectorName: "Arrival day(of week)",
      constraints: ["In"],
      valueType: "ChoiceList",
      valueChoices: ["Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"]
  }
  </code></pre>
  
  <p>Now I want to do this in my HTML:   </p>
  
  <pre><code>&lt;div class="col-xs-3" *ngIf="prototype.valueChoices"&gt;
              &lt;select class="form-control" [(ngModel)]="expression.valueChoice"&gt;
                  &lt;option *ngFor="#valueChoice of prototype.valueChoices" [value]="constraint"&gt;
                      {{ valueChoice }}
                  &lt;/option&gt;
              &lt;/select&gt;
          &lt;/div&gt;
  </code></pre>
  
  <p>Is it possible to check if the object contains an attribute like valueChoices than show the HTML like above. Or is this not the right way to do it?</p>