WebSphere Message Brokers
File: as01380_
Writer: Lorraine Waitt

Concept topic

This build: July 31, 2007 21:36:49

User-defined extensions overview

A user-defined extension is an optional component that you design and create to extend the functionality of WebSphere Message Broker. A user-defined extension can be either a node or a parser.

Create and implement the following types of user-defined extensions:

The user-defined nodes and parsers that you create can be used with the nodes and parsers supplied with the product, and with nodes and parsers supplied by other vendors. You can configure a user-defined node to use a user-defined parser.

You can write user-defined parsers only in the C programming language. You can write user-defined nodes in the C or the Java™ programming languages. User-defined nodes and parsers written in C must be compiled into a loadable implementation library (LIL): that is, a shared library on Linux® and UNIX® systems, or a dynamic link library (DLL) on Windows® systems. You must package user-defined nodes written in Java as a JAR file. You must import any user-defined nodes that you create into the Message Broker Toolkit before you can use them.

The samples gallery on the start screen of the Message Broker Toolkit has examples of user-defined nodes and parsers. Look at the following sample for an example of how a node is created and used. You can view samples only when you use the information center that is integrated with the Message Brokers Toolkit.

To achieve platform independence, use the ANSI standard C or Java programming languages, and avoid platform-specific code in your user-defined extension.

If you create user-defined nodes for WebSphere Event Broker users, ensure that you do not make it possible for users to evaluate ESQL code. For example, nodes that expose the input to MbSQLStatement as a node attribute would effectively be emulating a Compute node. Use of ESQL in WebSphere Event Broker is not supported.

WebSphere Event Broker is not shipped with the MRM parser, and user-defined parsers are not supported. User-defined input nodes can support only XML, BLOB, and the WebSphere MQ parsers.

The related links help you to understand how your user-defined extensions interact with other components of WebSphere Message Broker, such as message flows and execution groups. A good understanding of the broker architecture helps you to plan and construct user-defined extensions more effectively.

Related concepts
User-defined input nodes
User-defined message processing nodes
User-defined output nodes
User-defined parsers
Planning user-defined extensions
Designing user-defined extensions
User-defined extensions in the runtime environment
Node and parser factory behavior
Related tasks
Developing user-defined extensions
Related reference
User-defined extensions
C language user-defined node API
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This build: July 31, 2007 21:36:49

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