Building the Core – Enterprise Business Flows - Applied SOA Patterns on the Oracle Platform - page 198

With no intention of making our routing slip heavy or close to BPEL, we have to extend
its syntax a bit further. It is obvious that different tasks in our task sequence will require
different data subsets; even if we use a canonical XSD for our Order (actually, we are not
going to use it yet the TM Forum model is too "all-weather"). This fact will require addi-
tional transformations between invocations. We can perform these executions in the ad-
apter framework layer and relieve the Business Delegate from this functionality; however,
some of our service-workers will be other composites, standalone BPEL(s), or other ser-
vices that are not covered by the ABCS layer yet.
A separate lightweight Servlet can do it gracefully, making the solution truly universal;
however, because we have decided to stay in a single composite for now, the standard
BPEL functionality will be enough:
ora:processXSLT($TransformationFileName,
$TransformationInput)
Here, TransformationFileName is a task parameter, assigned in BPEL as shown in
the following code snippet:
<assign name="AssignFileName_and_Input">
<copy>
<from>
string($currentTask/ns15:taskList/ns15:task/
ns15:transform/@location)
</from>
<to>$TransformationFileName
</to>
</copy>
We must also supply the task worker (service provider) with additional information about
the transported business object. This information resides in the SBDH message header, the
Object Context part, and presented in the name/value pairs form, storing all objects' sup-
plemental information. Now we are ready to invoke the actual Service Provider.