SAP MDG · DATA MODEL UI
How do I implement custom logic in a redefined SAP MDG FPM feeder UIBB method such as GET_DATA, GET_FIELD_UI_PROP, or PROCESS_EVENT?
Use the redefinition-first pattern: keep the standard feeder behavior, read the MDG app context once, then apply only the custom delta for field usage, event handling, or data shaping. In MDG feeders, make UI changes conditional on the change request context and set the changed flags accurately.
Use the redefinition-first pattern: keep the standard feeder behavior, read the MDG app context once, then apply only the custom delta for field usage, event handling, or data shaping. In MDG feeders, make UI changes conditional on the change request context and set the changed flags accurately.
Custom SAP MDG feeder logic should follow a redefinition-first pattern: preserve standard behavior, then add only the delta needed for your UIBB. For runtime methods like `GET_DATA`, keep the logic deterministic per roundtrip, read the application context once, and set the change flags correctly. For UI control, branch on process or role mode and adjust `read_only`, `enabled`, and `visibility` only for the intended fields.
Process flow
- Redefine only the feeder method where the behavior actually changes.
- Read the MDG application context once with `CL_USMD_APP_CONTEXT=>GET_CONTEXT`.
- Check the current change request before applying UI or data changes.
- Call `super->method(...)` unless you intentionally replace the standard behavior.
- Adjust field usage or data structures only for the targeted attributes.
- Set the `ev_*_changed` flags correctly so the framework refreshes the UI as needed.
- Append a user message if the feeder needs to explain or warn about its behavior.
- Keep event handling, UI properties, and data changes separated logically inside the method.
Referenced tables
| Object | Purpose |
|---|---|
USMD120C | Change request lookup table used in the context-guarded CR read pattern. |
The remaining configuration, implementation details, and testing guidance continue from this answer more…
Related questions and keywords
Alternative questions
- How do I safely enhance an MDG feeder class with redefined methods?
- What is the correct pattern for custom logic in SAP MDG FPM feeder methods?
- How should I use CL_USMD_APP_CONTEXT in a custom UIBB feeder?
Possible questions
- How do I implement custom logic in a redefined SAP MDG FPM feeder UIBB method such as GET_DATA, GET_FIELD_UI_PROP, or PROCESS_EVENT?
- How do I safely enhance an MDG feeder class with redefined methods?
- What is the correct pattern for custom logic in SAP MDG FPM feeder methods?
- How should I use CL_USMD_APP_CONTEXT in a custom UIBB feeder?
- How do I make UIBB field behavior depend on change request context?