Product: OpenFusion Notification Service

Version: ALL

Description:

How to specify a filter?

Resolution:

Filters can be attached to either proxy objects or administration objects. There are proxy objects and administration objects for both event suppliers and event consumers.

Filters can be attached to proxy consumers, proxy suppliers, supplier administration objects, and consumer administration objects. This provides a very flexible system for specifying filters for groups of consumers, or for individual consumers.

A filter contains a constraint, specified in the Extended Trader Constraint Language. The constraint is evaluated every time an event is received by the object that the filter is attached to e.g. a consumer proxy object. If the constraint evaluates as TRUE, the event is forwarded to the next object in the delivery chain. If the constraint evaluates as FALSE, the event is not forwarded.

More details of filtering and the constraint language can be found in the OpenFusion Developer's Guide.