XML Schema extension

Recently working on a ARIBA-EBS integration, we decided to use/extend oagis schema. The approach was to create project specific wrapper xsds with the project specfic namespaces. Wherever there was need to extend a type, the [xsd:extension] was used. An example here, here and here


However whether to use the UserArea to put extension type or to define new types in the extension type - was a open question. Also by replacing the UserArea of type 'any' with our own custom type, in my opinion is defeating the purpose, as it would not be possible to accept any dynamic content at runtime.

One approach for dynamic xml content at runtime xsd polymorphic type [ xsi:type ]

What do you think?

BPEL - Java

Coming from a Java/J2EE background, one would think bpel is just drag and drop, however while working on an EAI type project on would definitely need Java. There are three types of Java extension in bpel

1. Custom XSL function for XSLT and XPATH
This fits best for any lookup functionalities, a good article here on how to do it.

The xslt function can return a nodelist, documentfragment, string, date, boolean. Nodelist is proper when a hashmap kind of collection is required. documentFragment can be used to return a dom tree. While calling the function from bpel/assign documentfragment works better.

for error handling, we are wrapping all exceptions as some error code in form of a nodelist.

2. Java Embedding
This fits best for invoking any Java from within bpel, If the Java code is developed in a layered manner, the same code can be used from XSLT or from bpel.

3. WSIF to Java Web Service
This is the web service approach to expose Java as service, and if it is co-located in the same server, WSIF can be used to optimize the call.

From a deployment perspective all the Java code/jar has to be deployed to all servers in a cluster.