HR P&F: Use WD application to launch form

Dear Experts

I got an unique requirement to display HR Processes and form in WDA instead of FPM form type or Adobe tool.

The client want to use existing WDA UI instead of building the same in FPM but want to use HR Processes and form tool to create/change infotype record. The reason they want to use HR P&F is to store the content of form in SCASE management once submitted/approved and its easy to retrieve the history instead of reading from Infotype.

We have used Composite form type to include WDA component as discussed in ( HCM Processes & Forms: Google Maps and how to step up your FPM forms game!) but have NO IDEA, how to retrieve data back & forth from WDA component controller context once we click SUBMIT button in HR P&F because the submit button is something outside of WDA.

We have comment the code in WDA to read/update directly from/to Infotype because the value to display in WDA has to come through HR P&F configuration.

Please advice, how to pass/read value from WDA application to HR P&F

Appreciate your support

Thanks

Babu