MRM XML physical format

An XML wire format describes the physical representation of a message that is written according to the standards given in the W3C Extensible Markup Language (XML) specification. The wire format defines information that is used to parse or write XML messages in a runtime environment such as a broker. XML versions 1.0 and 1.1 are both supported.

You can add more than one XML physical format to a message set, but within that message set, each physical format must have a unique name. The default name for an XML wire format is XML1. The physical format name identifies the definitions that are to be used by the broker at run time.

After adding an XML physical format, all XML properties for all existing objects in the message set are set to default values. Therefore, immediately after adding the format and deploying the message set to a runtime environment, you can process XML messages by using MRM features.

You can configure XML properties for the message set, and for objects within the message set. Objects that can have XML properties are messages, elements, and attributes. For example, a message object can be customized to define a specific DTD declaration on output; an element can have a tag name assigned to it which is different from its element name in the model.

Adding an XML wire format to a message set allows you to both process input messages, and to construct output messages in this format. You can also transform messages between XML and either CWF or TDS.

XML messages are, by their nature, self-describing: each piece of data is prefixed by a tag name or an attribute name. Therefore, it is possible for an XML message instance to contain elements that are not in the definition for that message.

• If such an element exists in the message set, the model objects for that element are used in parsing or writing the message.
• If the element does not exist in the message set, it is treated as a self-defining element, and its data type is set to string.

Although it is possible to define an XML message 'by hand', using the Message Definition Editor, IBM® Integration Bus also provides importers for both XML Schema and DTD, and these are often quicker and easier than manual definition.