Listeners

Listeners are used to listen to events on a particular object or list of objects. When an event occurs on the object that is listened to, the Service can invoke a Flow for it to take appropriate action.

More information on Listeners can be found in our documentation.

Annotations

There is a single annotation in the SDK that is used to create a Listener:

• @Listener.Metadata

@Listener.Metadata

The @Listener.Metadata annotation is used on a class to provide the SDK with the information for a listener.

Annotation Elements

• event (required) - the name of the event, and what the builder enters into their Flow must match with this

Interface

There is a single interface to define a Listener - Listener<C, T>.

Listener<C extends Configuration, T extends Type>

Generic Type Parameters

• C - this parameter must be the previously-defined Configuration Settings class
• T - this parameter must be a previously-defined Type

Methods

All the methods in this interface have C configuration as their first parameter, which is an instance of the Service's Configuration Settings class, populated with the appropriate values from the request.

They should also save the incoming listener data and register a webhook/trigger/event handler with the underlying application. There should also be a worker of some kind that processes incoming events from the underlying application, matches with any relevant stored listener data and triggers the Flow to progress forward.

void create(C configuration, T value, ListenerData listenerData)

This method is called when the incoming value to listen to is a single object.

Parameters

• configuration - an instance of the Service's Configuration Settings class, populated with the appropriate values from the request
• value - the object to listen to
• listenerData - a wrapper object containing the currently authenticated user information and the incoming ListenerServiceRequest

void createMultiple(C configuration, List values, ListenerData listenerData)

This method is called when the incoming value to listen to is a list of objects.

Parameters

• configuration - an instance of the Service's Configuration Settings class, populated with the appropriate values from the request
• values - a list of objects to listen to
• listenerData - a wrapper object containing the currently authenticated user information and the incoming ListenerServiceRequest

Example

An example for Listeners is coming soon. Feel free to open an issue or post a message on Gitter if you need any help with implementing them in your Service