title: why ng-pristine ng-invalid ng-invalid-required classes are added in Angular
body: <p>I am trying to implement form validation in Angular </p>
  
  <p>here is html</p>
  
  <pre><code>&lt;input type="email" placeholder="Email" ng-model="form.emailId"  name="email" required /&gt;
  </code></pre>
  
  <p>it is adding class 
  ng-pristine ng-invalid ng-invalid-required ng-valid-email</p>
  
  <p>And showing red border by default. </p>
  
  <p>I don't want to show Red border by default. i want to show on submit only. with HTML5 validations</p>
  
  <p>Any idea? How to do resolve this </p>
  
  <p>Thanks a lot</p>