javascript - Chosen Angular directive doesn't get updated -

i've followed great tutorial (link) chosen , angular (code pretty same)

here directive:

app.angularmodule.directive('chosen', function() {     var linker = function (scope, element, attrs) {         var list = attrs['chosen'];          scope.$watch(list, function () {             element.trigger('chosen:updated');         });          element.chosen({ width: '350px'});     };      return {         restrict: 'a',         link: linker     }; }); 

here html:

<select data-placeholder="choose category"  multiple class="col-lg-8 chosen-select" chosen="items"                             ng-options="item._backingstore.name item in items"   ng-model="selectedcategories" >                     </select> 

what want is, when user clicks edit button, modal window pops up, , categories selected before clicking edit button, selected in modal window.

here part of controller:

  $scope.$watch(function() { return admincrudservice.getcategoriesforupdate(); }, function() {                 $scope.action = "edit";                 $scope.categoriesforupdate = admincrudservice.getcategoriesforupdate();                 if ($scope.categoriesforupdate.length > null) {                     $scope.selectedcategories = _.filter($scope.items, function (item) {                         return _.contains($scope.categoriesforupdate, item);                     });                 }             }); 

i've logged $scope.selectedcategories , fine them, reason there nothing selected in chosen.

so doing wrong , how can fix ?

edit

i've noticed when select items, close modal, open again, selected values there again eve though put line inside $watch

$scope.selectedcategories = ""; 

edit 2

so left problem while, because had more important things deal with. i've tried without chosen, i.e. using "normal" select , code works. definitively chosen directive doesn't work should.

i've solved it, solution pretty easy , straightforward (when how angular directives work). here whole code directive:

app.angularmodule.directive('chosen', function() {     var linker = function (scope, element, attrs) {         var list = attrs['chosen'];          scope.$watch(list, function () {             element.trigger('chosen:updated');         });          scope.$watch(attrs['ngmodel'], function() {             element.trigger('chosen:updated');         });          element.chosen({ width: '350px'});     };      return {         restrict: 'a',         link: linker     }; });