Skip to content

Object Deleted Event Overview

When an object is deleted from the Backendless Real-Time Database, it instantly notifies connected clients about the change using the delete event. Objects can be deleted either using the Backendless Data API or in Backendless Console. A listener for the delete event can be notified about the deletion of either any object in the database or only of those which match a pattern expressed as a where clause.

An event listener itself is an object which receives a callback when an event is triggered by the real-time database. To add an event listener, it is necessary to obtain a handler for a database table first. The handler provides methods for registering an event listener.

Backendless Database provides two APIs for object deletion: (1) single object deletion and (2) deletion in bulk. As a result, there are two different types of listeners which can be added to an event handler: Single Object Deletion Listener and Bulk Deletion Listener.

Event listener functions for the Object Deleted Event must implement the following delegate:

public delegate void ObjectDeleted<T>( T obj );

where T is a type representing the deleted object in the Backendless database. If your code uses the Dictionary-based approach in the APIs, the type must be Dictionary<string, object>.