Extending PloneFormGen
All PFG types, adapters etc. are all based on Archetypes. Related example code can be found in PloneFormGen/content. The saveDataAdapter.py or fields.py files provide reasonable example code...
Are there any example add-ons where to look at when one would like to
1) Create custom action adapters for PloneFormGen
2) Add new field types to PloneFormGen