IBM BPM, V8.0.1, All platforms > Authoring services in Integration Designer > Services and service-related functions > Access external services with adapters > Configure and using adapters > IBM WebSphere Adapters > Adapter Toolkit > Implementing code from the IBM WebSphere Adapter Toolkit
Inbound event notification
When you enable inbound event-notification, business processes are alerted to changes in, or new information about, an EIS.
Inbound event notification complements outbound request processing, enabling adapters to provide bidirectional communication between business processes and EIS applications. Depending on the underlying EIS, the business events an adapter generates may span the set of changes that have occurred to a given entity in the EIS, such a customer changing the quantity in their order from 10 to 100, to a complete document or binary payload such as an insurance claim form submitted in XML.
Although each EIS application is unique, most adapters implement inbound event-notification in similar ways:
- Create an event store in the target EIS to persist changes or other relevant event data that is published by the adapter.
- Implement an event detection mechanism in the EIS. This mechanism is responsible for detecting any changes of interest (to the adapter) in the EIS and recording them in the event store.
- Implement an event retrieval mechanism in the adapter that can detect and retrieve events from the event store described in (1) above.
- Implement a data transformation mechanism in the adapter to convert EIS events to WebSphere business objects for use by target business processes.
Inbound event notification
- Use the IBM WebSphere Foundation Classes for inbound event notification
Although not required, use of the IBM WebSphere Foundation Classes is strongly recommended for adapters that need to provide event notification. - Assured once-and-once-only event delivery
XA transactions support once-and-only-once event delivery. - Implementing an event store in the EIS
An event store is a persistent storage area in the EIS application where event records are saved until the adapter can process them. The event store might be a database table, application event queue, email inbox, or any type of persistent store. A persistent event store enables the application to detect and save event records for the adapter even when the adapter is not operational. - Implementing event retrieval in the adapter
The careful work of implementing event retrieval in the adapter uses two Foundation Classes interfaces. The goals are setting up event polling and a safe, reliable connection to the event store. - Possible event store implementations
An event store is typically implemented in a database, however, any structured persistence mechanism could be used.