For some of the delegations, there is support for a JSP/JSF EL like expression language. In actions, assignments and decision conditions, you can write an expression like e.g. expression="#{myVar.handler[assignments].assign}"

The basics of this expression language can be found in the J2EE tutorial.

The jPDL expression language is similar to the JSF expression language. Meaning that jPDL EL is based on JSP EL, but it uses #{...} notation and that it includes support for method binding.

Depending on the context, the process variables or task instance variables can be used as starting variables along with the following implicit objects:

This feature becomes really powerfull in a JBoss SEAM environment. Because of the integration between jBPM and JBoss SEAM, all of your backed beans, EJB's and other one-kind-of-stuff becomes available right inside of your process definition. Thanks Gavin ! Absolutely awsome ! :-)