Message Sets: Message definition files

A message definition file contains the messages, elements, types, and groups which make up a message model within a message set.

Tip: Message definition files are used when working with message sets. A message set is the original container for message models used by IBM® Integration Bus. In WebSphere® Message Broker Version 8.0 and later, message model schema files contained in applications and libraries are the preferred way to model messages for most data formats. Message sets continue to be supported, and are required if you use the MRM or IDOC domains. If you need to model data formats for use in the MRM or IDOC domains, you must first enable message set development in the IBM Integration Toolkit. For more information, see Enabling message set development .

Every message set requires at least one message definition file to describe its messages. Message definition files use the XML Schema language to describe the logical format of one or more messages. Extra information in the form of XML Schema annotations is used to describe any physical formats that you define for the messages.

Large message sets can contain several message definition files. This keeps the individual files to a manageable size, making them faster and easier to work with.

Message definition files can be created by using the Message Definition editor, or can be imported from a range of different file formats as described in Importing from other model representations to create message definitions.

A message definition file can be associated with a namespace, so that all message model objects that are declared within the file belong to that namespace. Namespaces provide a means of avoiding name clashes among similarly named global objects. They are described in detail in Namespaces in the message model.

One message definition file can reuse message model objects that are defined in another message definition file. XML Schema provides two mechanisms to do this: import and include. For more information, see Reusing message model files.