title: AngularJS form validation: show error message for checkbox after click on submit
body: <p>With AngularJS, how can I show an error message for a checkbox after a click on submit button if the checkbox isn't checked?</p>
  
  <p>I tried this :</p>
  
  <pre><code>&lt;form action="/" method="post" name="myForm" novalidate&gt;
      &lt;label&gt;
          &lt;input type="checkbox" name="myCheckbox" ng-model="myCheckbox" value="1" required&gt;
      &lt;/label&gt;
      &lt;p class="error" ng-show="myForm.$submitted &amp;&amp; myForm.myCheckbox.$error.required"&gt;Error message&lt;/p&gt;
      &lt;button type="submit" ng-disabled="myForm.$invalid"&gt;Submit&lt;/button&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>But it didn't work. When I click on submit button, nothing is happening. If I remove "novalidate" on form tag or "ng-disabled" on submit button, the form is submitted even if the checkbox is not checked.</p>
  
  <p>Can you help me please ?</p>