Expression Resolving

The camunda-engine-cdi library exposes CDI beans via Expression Language, using a custom resolver. This makes it possible to reference beans from the process:

<userTask id="authorizeBusinessTrip" name="Authorize Business Trip"
                        camunda:assignee="#{authorizingManager.account.username}" />

Where “authorizingManager” could be a bean provided by a producer method:

@Inject
@ProcessVariable
private Object businessTripRequesterUsername;

@Produces
@Named
public Employee authorizingManager() {
        TypedQuery<Employee> query = entityManager.createQuery("SELECT e FROM Employee e WHERE e.account.username='"
                + businessTripRequesterUsername + "'", Employee.class);
        Employee employee = query.getSingleResult();
        return employee.getManager();
}

We can use the same feature to call a business method of an EJB in a service task, using the camunda:expression="${myEjb.method()}"-extension. Note that this requires a @Named-annotation on the MyEjb-class.