Bulk Delete Listener¶
Listeners for bulk deletion work identically to the ones for single deletion. The difference is in the method names to add and remove listener objects:
Conditional bulk delete listener¶
A conditional bulk delete listener receives an event when an API client uses the bulkDelete
API to delete multiple objects in a table with the same whereClause statement as specified by the RT client:
const eventHandler = Backendless.Data.of( 'TABLE-NAME' ).rt();
const callback = ({ whereClause, count }) => console.log( whereClause, count )
const onError = ({ message, code }) => console.log( 'Error:', message, 'Error Code:', code )
eventHandler.addBulkDeleteListener( whereClause, callback, onError );
const eventHandler = Backendless.Data.of( TABLENAMECLASS ).rt();
const callback = ({ whereClause, count }) => console.log( whereClause, count )
const onError = ({ message, code }) => console.log( 'Error:', message, 'Error Code:', code )
eventHandler.addBulkDeleteListener( whereClause, callback, onError );
Unconditional bulk delete listener¶
A unconditional bulk delete listener receives events when a client uses the bulkDelete
API with any whereClause
statement:
const eventHandler = Backendless.Data.of( 'TABLE-NAME' ).rt();
const callback = ({ whereClause, count }) => console.log( whereClause, count )
const onError = ({ message, code }) => console.log( 'Error:', message, 'Error Code:', code )
eventHandler.addBulkDeleteListener( callback, onError );
const eventHandler = Backendless.Data.of( TABLENAMECLASS ).rt();
const callback = ({ whereClause, count }) => console.log( whereClause, count )
const onError = ({ message, code }) => console.log( 'Error:', message, 'Error Code:', code )
eventHandler.addBulkDeleteListener( callback, onError );
Both conditional and unconditional event listeners receive the following information in the callback object. The properties listed below are included into the object delivered to the listener's callback.
whereClause
- the where clause value used in the API call to identify the objects deleted from the database.count
- the number of objects deleted from the database.
Removing listeners¶
The method removes all registered listeners for the bulkDelete
event:
eventHandler.removeBulkDeleteListeners();
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 addBulkDeleteListener
method:
eventHandler.removeBulkDeleteListeners( whereClause );
Removing a specific listener¶
This method removes a listener identified by the callback object:
eventHandler.removeBulkUpdateListener( callbackObject );