Removing Listeners¶
Listener objects can be removed when the application is no longer interested in receiving real-time updates. A listener (or all of them) should be removed from the same event handler object which they were added to. The following listener removal APIs are available:
Removing all listeners¶
The method removes all registered listeners for the delete
event:
// for the class-based approach:
EventHandlerForClass *eventHandler = [Backendless.shared.data of:[Order class]].rt;
[eventHandler removeDeleteListeners];
// for the map-based approach:
EventHandlerForMap *eventHandler = [Backendless.shared.data ofTable:@"Order"].rt;
[eventHandler removeDeleteListeners];
// for the class-based approach:
let eventHandler = Backendless.shared.data.of(Order.self).rt
eventHandler?.removeDeleteListeners()
// for the map-based approach:
let eventHandler = Backendless.shared.data.ofTable("Order").rt
eventHandler?.removeDeleteListeners()
The method below removes all listeners which process events for a specific where clause.
The value of the whereClause
argument must be the same as one in the addDeleteListener
method:
// for the class-based approach:
EventHandlerForClass *eventHandler = [Backendless.shared.data of:[Order class]].rt;
[eventHandler removeDeleteListenersWithWhereClause:@"orderAmount > 1000"];
// for the map-based approach:
EventHandlerForMap *eventHandler = [Backendless.shared.data ofTable:@"Order"].rt;
[eventHandler removeDeleteListenersWithWhereClause:@"orderAmount > 1000"];
// for the class-based approach:
let eventHandler = Backendless.shared.data.of(Order.self).rt
eventHandler?.removeDeleteListeners(whereClause: "orderAmount > 1000")
// for the map-based approach:
let eventHandler = Backendless.shared.data.ofTable("Order").rt
eventHandler?.removeDeleteListeners(whereClause: "orderAmount > 1000")
Removing a specific listener¶
This method removes a listener identified by a subscription that contains this listener.
// for the class-based approach:
EventHandlerForClass *eventHandler = [Backendless.shared.data of:[Order class]].rt;
RTSubscription *subscription = [eventHandler addDeleteListenerWithResponseHandler:^(Order *deletedObject) {
NSLog(@"Order has been deleted: %@", deletedObject);
} errorHandler:^(Fault *fault) {
NSLog(@"Error: %@", fault.message);
}];
[subscription stop];
// for the map-based approach:
EventHandlerForMap *eventHandler = [Backendless.shared.data ofTable:@"Order"].rt;
RTSubscription *subscription = [eventHandler addDeleteListenerWithResponseHandler:^(NSDictionary *deletedObject) {
NSLog(@"Order has been deleted: %@", deletedObject);
} errorHandler:^(Fault *fault) {
NSLog(@"Error: %@", fault.message);
}];
[subscription stop];
// for the class-based approach:
let eventHandler = Backendless.shared.data.of(Order.self).rt
let subscription = eventHandler?.addDeleteListener(responseHandler: { deletedObject in
print("Order has been deleted: \(deletedObject)")
}, errorHandler: { fault in
print("Error: \(fault.message ?? "")")
})
subscription?.stop()
// for the map-based approach:
let eventHandler = Backendless.shared.data.ofTable("Order").rt
let subscription = eventHandler?.addDeleteListener(responseHandler: { deletedObject in
print("Order has been deleted: \(deletedObject)")
}, errorHandler: { fault in
print("Error: \(fault.message ?? "")")
})
subscription?.stop()