Building the Core – Enterprise Business Flows - Applied SOA Patterns on the Oracle Platform - page 208

• location : This is the concrete service URI and will be used further for substituting
in a generic endpoint. This is necessary for distinguishing endpoint types.
• taskDomain : This is an optional element for routing to the specific business do-
main (another Mediator or Service Broker in a separate business domain). It could
be the CRM, ERP, SCM, and so on. Use your own business landscape, but this
element in general contradicts the agnostic nature of our Service Broker.
• serviceEngine type : This was not shown earlier, but it is quite a useful element
that you can declare as a service engine that will be responsible for executing
tasks such as BPEL, Transformation, and DB. It's especially relevant for trans-
formations, as they can display different behavior in complex compositions. You
can route to the specific engine using this element.
We are still in Mediator's request path. Here, there are three things that we should
consider (following the logic of our solution).
• Assign value : This is the field that does all the magic. Using mediators' properties
(we have plenty of useful properties; please read about these in the documenta-
tion, as we have no place to discuss them here), endpointURI in particular, we
can assign our service URI from the execution plan dynamically, resolving any
address issues according to the selected MEP.
Tip
Please remember that the Mediator has inbound and outbound properties, and it
could happen that you will not find the right property in the drop-down list. Just
type property in the dialog box field and make sure that you spell it correctly.
It's not a bug; it's a long lasting feature now.
• Content transformation : This is another highly important feature of Mediator.
Yes, we are trying to minimize transformations within a single service domain;
however, with the huge legacy application burden, it's not always possible. For an
agnostic Composition Controller, it is even more inevitable, as we need to extract
(by means of XSLT) the payload from our agnostic message container (CTUMes-
sage) because the endpoint application cannot handle the entire container. Appar-
ently, we would prefer to do this in the ABCS layer as transformations are usually
associated with adapters.
• The Validate Semantic operation : This is provided by the Schematron tool or
XSD validation, and the most interesting part of this feature is that we could ap-
ply the Partial Validation SOA pattern, checking only part of the message, thereby
considerably reducing the time to perform quite an expensive XML operation. As