Infusion component developers are encouraged to avoid using "init" functions (preInit, postInit, finalInit) whenever possible. "init" functions are in the process of being deprecated from the framework. Instead, attaching listeners onto life cycle events is encouraged and able to achieve the same goal. "finalInitFunction" can usually be replaced by attaching listener onto "onCreate" event.

http://wiki.fluidproject.org/display/docs/Understanding+Component+Lifecycle+Events