Intel SOA Expressway Extension Functions provide many powerful and low level functions that are commonly used in workflows in the f(x) action. It is also possible to use them in style sheets (XSLT) which SOAE executes within the workflow.
There are reasons you may wish to do this such as needing to dynamically change parts of the workflow by using remote XSLT files. Or not wanting to break up an XSLT file into many parts just to go back into the workflow to run an extension function.
Here's how to write a message to the transaction log from within your XSLT. We're assuming you have constructed a basic workflow and already have an XSL Transform action within it.
The basic form would look like this:
<?xml version="1.0" encoding="ISO-8859-1"?>
There are three parts to remember:
1, Make sure your transform has the soae-xf, exslt or soae-cache namespace declared.
2, Declare your Extension Function with a variable. In this case $log.
3, Do something with the variable to force the evaluation of the variable. In this case we test $log for some contents. This is a necessary step since one of the performance features of the XSLT engine is lazy parsing which eliminates the evaluation of variables which may turn out to be unnecessary.