Message Template

The message template is responsible for formatting the data appropriately for the type of service being used. The message must be text, as that is what is produced by the template engine. Certain service types may have additional requirements—namely, a web service endpoint will only accept messages consisting of valid XML.

The Outbound Services Connector operates using a template system for messages as opposed to XSLT. There are two key advantages to this approach. First, it avoids the overhead of building an intermediate XML format from the data. Second, it allows the template to interact directly with the data structures from OIPA.

Message templates are used to define the outgoing data payload. Payload formats differ depending on the type of delivery used. SOAP delivery requires a valid XML document. File and JMS delivery support any text format.

The message template language used in the Outbound Services Connector is FreeMarker. The FreeMarker Template Author Guide and Syntax Reference cover all of the functionality available.

The extension is responsible for exposing data to FreeMarker so it can be used in template processing. However, data is derived from the OIPA extension point in use. For the Math Transaction extension, all elements passed as parameters are exposed to the template by their NAME attribute. More information about passing data to the OSC can be found in the Extension Invocation section of this document.