Is it automatically unbinding watchers and scope events that are bound with $scope.$on(...) or $scope.$watch(...) when the scope is destroyed in Angular?
Let's consider the following code:
$scope.$on('someEvents', handleSomeEvent);
$scope.$watch('someProperty', handleSomePropertyChange);
Do I have to manually unbind these watchers and events when the $destroy event is triggered on the scope?
Per the Angular documentation regarding $scope:
The method '$destroy()' should be invoked on a scope when you want to completely detach it and its child scopes from the parent, ceasing their involvement in model change detection and listener notification.
Moreover,
This removal also signifies that the current scope can now be cleared for garbage collection.
This implies that upon calling $destroy(), all watchers and listeners will be eliminated, rendering the scope object as eligible for garbage collection.
Reviewing the destroy() source code reveals a line:
forEach(this.$$listenerCount, bind(null, decrementListenerCount, this));
This line is designed to remove all listeners.
As pointed out by @glepretre, this pertains to the watchers and listeners within the controller. The aforementioned documentation also mentions:
It's worth noting, in AngularJS, there exists a $destroy jQuery event that can assist in cleaning up DOM bindings prior to removing an element from the DOM.
Hence, if specific listeners exist in directives, one should listen for the $destroy event and perform any required cleanup actions accordingly.
When dealing with events in Angular, the unbinding process can be automated if the scope is within a controller. If not, you have the option to manually unbind the event by invoking the returned function like so:
var myEvent = $scope.$on('someEvents', handleSomeEvent);
myEvent(); // This will unbind the event
Angular takes care of cleaning up after itself, most of the time. For example, if you use
$scope.$on('someEvents', handleSomeEvent);However, it's important to remember that $rootScope is never destroyed unless you close your app. So if you use
$rootScope.$on('someEvents', handleSomeEvent);controller or directive, you will need to remove the event listener yourself. Otherwise, every time you instantiate the controller, a new event listener will be attached, leading to multiple calls to handleSomeEvent.service, you do not need to remove the event listener manually, as services are always singletons (it's worth noting that in Angular, services, factories, etc., all essentially serve the same purpose).The scalePhotos option in Colorbox does not seem to be working correctly for me. I have tried various methods to set it, including initializing Colorbox using the following code snippet right before the closing </body> tag in my HTML: jQuery('a ...
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