Message modeling concepts

Message modeling is a way of predefining the message formats that are used by your applications.

Modeling your message formats is necessary for IBM® Integration Bus to understand some data formats, but simplifies the development of message flows regardless of the data format that you are processing. For a full description of the advantages of using message models, see Why model messages?.

When you model messages, you must understand the following concepts:
  • Message models
  • Schema files
  • Domains and parsers
  • New Message Model wizard
  • Model editors
  • Model generators
  • Model validator
Additionally, you might have to understand the following concept:
  • Message sets
Tip: 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 .

For more information about applications and libraries, see Resource management overview. For a description of message sets, see Message Sets: Message sets overview. The remainder of this topic describes message model schema files.

The following figure shows the different types of files that comprise a message model in a library or application. It shows the formats that can be imported by using the New Message Model wizard.

This diagram shows the contents of schema files, and the relationship between the message model components and the integration node and toolkit.
Note: SCA Imports and Exports are imported using message sets, not message models.

A message model is used by IBM Integration Bus to model a message format. The message models used by IBM Integration Bus are based on W3C XML Schema.

The following table shows the different message formats supported by IBM Integration Bus, and the message model schema file that is used to model each format:
Format Message model schema file
SOAP XML XML Schema 1.0 and WSDL 1.0
Other XML XML Schema 1.0
CSV Data Format Description Language 1.0
Other delimited Data Format Description Language 1.0
Industry standard text or binary data Data Format Description Language 1.0
Custom text or binary data Data Format Description Language 1.0
COBOL structure Data Format Description Language 1.0
C structure Data Format Description Language 1.0
PL/I structure Data Format Description Language 1.0
CORBA IDL XML Schema 1.0
SCA import or export Message sets only
SAP WebSphere Adapter Schema or message sets
Siebel WebSphere Adapter Schema
PeopleSoft WebSphere Adapter Schema
JDEdwards WebSphere Adapter Schema
Database record XML Schema 1.0
JSON The JSON parser does not use a model.
MIME The MIME parser does not use a model.

XML Schema 1.0 (XSD) is an open standard modeling language from the World Wide Web Consortium (W3C) that was designed to model and validate XML documents. However, it can also be used to express the logical structure of all data formats. For more information about XML Schema, see XML Schema.

Data Format Description Language 1.0 (DFDL) is an open standard modeling language from the Open Grid Forum (OGF) that builds upon the features of XSD 1.0 in order to model and validate all kinds of general text and binary data. It uses standard XSD model objects to express the logical structure of the data, together with DFDL annotations to describe the text or binary physical representation. For more information about DFDL, see Data Format Description Language (DFDL).

WebSphere Adapter Schema is an IBM extension to XSD 1.0. It uses the standard XSD model objects to express the logical structure of data, along with special annotations that are used when exchanging data with EIS systems that use the WebSphere Adapters of the integration node.

When you have created an IBM Integration Bus application or library, you can add existing DFDL schema, XSD schema (and any associated WSDL files) and WebSphere Adapter schema files directly into your application or library, or add them to a folder within your project. Alternatively, you can create message model schema files by any of the following methods:
  • o Using the XSD or DFDL editors in the IBM Integration Toolkit
  • o Importing from other files (for example XML DTD or COBOL copybooks)
  • o Generating a model from an example data stream (XML only)
  • o Connecting direct to EIS systems or databases

When a message model schema has been created, it can be edited to refine the model. Specific editors are provided for XSD schema and DFDL schema. Adapter schemas are edited if necessary using the XSD schema editor. A WSDL editor is also provided. For more information about the available editors and their functions, see Editors.

A message model schema consists of a number of different model objects. For more information about message model objects, see Message model objects.

When your message model schemas are complete, you can use them in developing your message flow. For more information, see Why model messages??