title: AngularJS input url invalid/valid/error
body: <p>I've a mistake with input type url in angularjs. I would disable the button if input is empty or invalid and I wrote the code below. Well, it's fine on the first time o if I write an incorrect url but if it's empty propForm.imgUrl.$invalid and propForm.imgUrl.$error.url it returns me false and this enable click of button</p>
  
  <pre><code>    &lt;div class="col-sm-10"&gt;
            &lt;input type="url" name="imgUrl" ng-model="$parent.urlImage" class="form-control"&gt;
              &lt;/div&gt;
                  &lt;div class="pull-right col-sm-2"&gt;
                     &lt;a href="" class="btn btn-default btn-primary" ng-disabled="propForm.imgUrl.$invalid || propForm.imgUrl.$pristine || propForm.imgUrl.$error.url" ng-click="addImage()"&gt;Add&lt;/a&gt;
                   &lt;/div&gt;
  </code></pre>
  
  <p>Where is the trick?a</p>