title: AngularJS radio button validation
body: <p>Simple and easy.</p>
  
  <p>I got two radio buttons.</p>
  
  <pre><code>&lt;input type="radio" name="gender" ng-model="male"&gt;
  &lt;input type="radio" name="gender" ng-model="female"&gt;
  </code></pre>
  
  <p>How do i validate in AngularJS that at least one is chosen? And how can i type something like </p>
  
  <pre><code>$scope.myForm.gender.$invalid
  </code></pre>
  
  <p>Any ideas?</p>