ui-选择必填字段验证

Question

我们是否可以将默认的HTML必填字段验证警告框设置为UI-Select，如同给定链接中的那个..如果是这样的话？

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编辑：我的代码就像

<ui-select ng-model="selectedName" name="nameSelect" required>
   <ui-select-match allow-clear="true" placeholder="Select a value">
   {{$select.selected.firstname + ' ' +$select.selected.lastname }}
   </ui-select-match>
   <ui-select-choices repeat="name in names | propsFilter: {firstname: $select.search, lastname: $select.search}" >
       <div ng-bind-html="name.firstname +  ' '+name.lastname   | highlight: $select.search">
       </div>
  </ui-select-choices>
</ui-select>

将名称列为用户的名字和姓氏。