angularjs - How to respond to an md-slider while it is being dragged? -

i've got md-slider , controller correctly updates volume when drag event has finished; when ng-model changed.

this code in controller watches volume property/attribute.

$scope.$watch(         function () {             return $scope.volume;         },         function (newvalue, oldvalue) {             $scope.changevolumevianumberinput();         } ); 

this html renders slider.

<div>     <label class="body">volume</label>     <md-slider md-discrete aria-label="volume" ng-model="volume" min="0" max="100">     </md-slider> </div> 

what have add enable controller respond drag event?

it resolved removing md-discrete.

<div>     <label class="body">volume</label>     <md-slider aria-label="volume" ng-model="volume" min="0" max="100">     </md-slider> </div>