These are the basic steps that Chameleon follows when implementing scripted transformation:

• The message is preprocessed using the standard Global Inbound Script (Chameleon > Global Inbound Script);
• Chameleon uses its standard message identification logic to work out the message type; and
• The Transformation Script for the message type is invoked. This is the script that performs the actual transformation.

The order of Python execution for transformation is described in the following diagram:

So typically the main work in setting up the scripted transformation is defining the message identities and then writing a transformation script for each one in Python. Scripted transformation does not actually make use of the segment grammar definition unlike other parsing operations in Chameleon.