Unconditional Delivery Listeners¶
The where clause
argument in the addDeleteListener
method is optional. When it is not provided, the real-time database will deliver any object which is being deleted from the database's table:
const orderEventHandler = Backendless.Data.of( 'Order' ).rt(); const onObjectDeleted = object => console.log( 'an Order object has been deleted. Object Id - ', object.objectId ); const onError = error => console.log( 'Server reported an error', error ); orderEventHandler.addDeleteListener( onObjectDeleted, onError );
function Order() { this.objectId = undefined; this.orderAmount = 0; } const orderEventHandler = Backendless.Data.of( Order ).rt(); const onObjectDeleted = object => console.log( 'an Order object has been deleted. Object Id - ', object.objectId ); const onError = error => console.log( 'Server reported an error', error ); orderEventHandler.addDeleteListener( onObjectDeleted, onError );