AngularJS ngMessages 模块

<form name="myForm">
  <label>
    Enter your name:
    <input type="text"
           name="myName"
           ng-model="name"
           ng-minlength="5"
           ng-maxlength="20"
           required />
  </label>
  <pre>myForm.myName.$error = {{ myForm.myName.$error | json }}</pre>

  <div ng-messages="myForm.myName.$error" style="color:maroon" role="alert">
    <div ng-message="required">You did not enter a field</div>
    <div ng-message="minlength">Your field is too short</div>
    <div ng-message="maxlength">Your field is too long</div>
  </div>
</form>