title: How to make a ui-select field as required?
body: <p>I want to make the following field (settings) in my form as a required field in. How can I do it?</p>
  
  <pre><code>&lt;div class="form-group"&gt;
      &lt;label class="col-xs-5 control-label"&gt; Settings*&lt;/label&gt;
  
      &lt;div class="col-xs-7"&gt;
          &lt;ui-select multiple tagging="adPreferredEmailDomainPatternTransform" id="emailDomainPatternListInput"
                     tagging-tokens="SPACE|," theme="bootstrap"
                     ng-disabled="settings.enableAuthentication == 'false'"
                     ng-model="settings.emailDomainPatternList"&gt;
              &lt;ui-select-match&gt;{{$item.displayFormat}}&lt;/ui-select-match&gt;
              &lt;ui-select-choices repeat="item in emailDomainPatterns"&gt;
                  {{item.displayFormat}}
              &lt;/ui-select-choices&gt;
          &lt;/ui-select&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>