AngularJS- Prompting the user before routing to other controller to save changes -

i have form in controller. if there unsaved change want warn user loosing them when leaving.

first tried:

$scope.$on('$locationchangestart', function (event, next, current) {      if ($scope.settingsform.$dirty) {          event.preventdefault();          $scope.theuserwantstoleave(function (result) {              if (result === "leave") {                  $location.path($location.url(next).hash());                 $scope.$apply();              }         });     } 

the code above throws error in line $scope.$apply();:

error: $digest in progress 

removing line don't execute redirect.

what right way it?

===

edit:

other option tried handling reacting when need cancel redirection:

  $scope.$on('$locationchangestart', function (event, next, current) {      if ($scope.settingsform.$dirty) {        $scope.theuserwantstoleave(function (result) {          if (result === "stay_here") {            event.preventdefault();          }           });         } }); 

when doing things way, ui breaking (i see dialog , gone). seems can't call async method while handling event.

i've managed interrupt route change listening $locationchangesuccess , assigning $route.current last route.

also, if $scope.theuserwantstoleave async, callback passed may fire late stop route change. around async call using blocking flag, such oktodiscardchanges in examples.

js:

$scope.oktodiscardchanges = false;  var lastroute = $route.current;     $scope.$on('$locationchangesuccess', function () {     if ($scope.settingsform.$dirty && !$scope.oktodiscardchanges) {         $route.current = lastroute;         $scope.errormessage = 'you have unsaved changes. sure want leave?';     } }); 

html:

<form name="settingsform">     <!-- form stuff --> </form>  <div ng-show="errormessage">     {{ errormessage }}     <label>         <input type="checkbox" ng-model="oktodiscardchanges"> discard changes     </label> </div> 

hope works!