Listeners

Coyote DX Listeners are notified by the Transform Engine when events occur during the run cycle. One or more listeners can be registered with the Transform Engine to perform processing at specific points in the process.

A common listener simply logs when validations errors occur so problems with data quality can be recorded. Other listeners track the beginning and ending of the Transaction Context and the Transform Context to determine throughput for each transaction and the job overall.

When an event occurs, each of the listeners is notified with the context in which the event occurred so the Listener has all the data and references it needs to perform its processing.

Events and Listeners are a great way to extend the toolkit to perform complex processing specific to your needs.

Frame Processing

Because Listeners are triggered at several points in the transformation process, they are the ideal location for performing business logic for each frame.

For example, it is sometimes necessary to record when a business object has been exported to an external entity so its state in the system can be tracked. A listener can be used to record the fact that a purchase order header, for example, has been sent to a business partner.

Custom Listeners

Listeners can be written to perform any manner of processing at different points in the process. Some listeners are written to copy data to another technology stack. Other listeners keep track of the data passing through the transform context and perform processing when trends have been spotted. Listeners have a peek into the data stream and the opportunity to act based on what they observe.

Technically, Listeners do not alter the data in the transform, that function is performed by transform components. Listeners perform processing outside the process. They gather data, perform analysis and processing relating to other systems and processes.