title: Validation on a list of checkboxes Angular 2
body: <p>I have a list of business units that are rendered as checkboxes on a registration form along with a textbox field and am doing validation.</p>
  
  <pre><code> &lt;label for="inputFirstName" class="sr-only"&gt;First name&lt;/label&gt;
  &lt;input type="text" formControlName="firstName" class="form-control" placeholder="First name"&gt;
  
   &lt;div class="checkbox" *ngFor="let bu of businessUnits"&gt;
          &lt;label&gt;&lt;input type="checkbox" #instance value="{{bu.BuName}}" (click)="getCheckBoxValue(instance.checked, bu.BuName)"&gt;{{bu.BuName}}&lt;/label&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>The list of business units are retrieved from a database table and it is rendered when the form loads</p>
  
  <pre><code>businessUnits: BusinessUnit[] = [];
  </code></pre>
  
  <p>In the constructor I am validating the email like this</p>
  
  <pre><code>  "firstName": new FormControl('', [Validators.required]),
  </code></pre>
  
  <p>})</p>
  
  <p>How would I go about in validating that at least one check box of the list of checboxes the were loaded dynamically on page load is checked?</p>
  
  <p>Thanks</p>