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