AngularJS slider (wrapped jquery-ui slider)

HTML

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="http://code.jquery.com/ui/1.10.2/jquery-ui.js"></script>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.10.2/themes/smoothness/jquery-ui.css">
<div ng-app="myApp">
    <div ng-controller="SomeController">
        <div slider config="sliderConfig" model="values" class="cdbl-slider"></div>
        <button ng-click="addRange()">Click</button>
    </div>
</div>

CSS

.cdbl-slider {
    width: 400px;
    margin: 10px;
}

JavaScript

var myApp = angular.module("myApp", []);

myApp.controller("SomeController", function ($scope) {
    $scope.sliderConfig = {
        min: 0,
        max: 100,
        step: 1
    }
    
    $scope.addRange=function(){
       $scope.values.push(50); 
    }

    $scope.values=[];
});

myApp.directive("slider", function () {
    return {
        restrict: 'A',
        scope: {
            config: "=config",
            values: "=model"
        },
        link: function (scope, elem, attrs) {
            $(elem).slider({
                min: scope.config.min,
                max: scope.config.max,
                step: scope.config.step,
                values:scope.values,
                slide: function (event, ui) {
                    scope.$apply(function () {
                        //scope.price = ui.value;
                    });
                }
              });
            scope.$watch('values.length',function(){
                $(elem).slider("destroy");
                $(elem).slider({
                min: scope.config.min,
                max: scope.config.max,
                step: scope.config.step,
                values:scope.values,
                slide: function (event, ui) {
                    scope.$apply(function () {
                        //scope.price = ui.value;
                    });
                }
              }).append('<button style="width: 100%;height:inherit;position:absolute"></button>');
          })           
        }
    }
});