Databases Reference
In-Depth Information
For each method on the canonical interface, we must map it onto a method in the
physical interface. We do this by selecting the appropriate method from the business
service operation drop-down box. We need to do this because the methods provided
in the external service do not match the method names in our canonical service. In
the following example, we have mapped onto the
SearchAddress
method.
Having selected an operation, we now need to transform the input data from the
format provided by the canonical interface into the format required by the external
service. We need to map the request and response messages if it is a two-way
method or just the request message for one-way method. The actual mapping may
be done either by XQuery or XSLT. In our example, we will use the XSLT transform.
To perform the transformation, we add a
Messaging Processing
action to our
message flow, which in this case is a
Replace
operation. The variable body always
holds the message in the Service Bus flow. This receives the message through the
proxy interface and is also used to deliver the message to the business service
interface. This behavior differs from BPEL and most programming languages, where
we typically have separate variables for the input and output messages. We need to
transform this message from the proxy input canonical format to the business service
native output format.
