how to emit events from a factory

Question

How can I emit events from a factory or service. I am unable to inject $scope into the factory, thus unable to emit events.

I get the following error - Unknow

Answer 1

You cannot inject a controller's scope into a service. What you can do is:

• pass the scope instance as a parameter to one of your service functions:

e.g.

app.factory('MyService', function() {

   return {
      myFunction: function(scope) {
         scope.$emit(...);
         ...
      }
    };
});

• inject the $rootScope into your service:

e.g.

app.factory('MyService', ['$rootScope', function($rootScope) {

   return {
      myFunction: function() {
         $rootScope.$emit(...);
         ...
      }
    };
}]);

Answer 2

Inject $rootScope instead of $scope and then emit it on the $rootScope.

myApp.factory('myFactory', ['$rootScope', function ($rootScope) {
    $rootScope.$emit("myEvent", myEventParams);
}]);

Factories don't have access to the current controller/directive scope because there isn't one. They do have access to the root of the application though and that's why $rootScope is available.

Answer 3

In your factory inject $rootScope as-

myApp.factory('myFactory',function($rootScope){
return({
// use $rootScope as below to pass myEventParams to all below in hierarchy
$rootScope.$broadcast("myEvent",myEventParams);

})
}]);