SAP MDG · DATA MODEL UI
How do I implement custom MDG FPM feeder logic in redefined GET_DATA, GET_FIELD_UI_PROP, PROCESS_EVENT, and GET_DEFINITION methods?
Use the standard MDG feeder as the base, redefine only the methods where behavior changes, read the application context once, keep GET_DATA deterministic, and call super unless you intentionally override standard behavior. For search GUIBBs, normalize criteria in PROCESS_EVENT before delegating to super; for form/list feeders, adjust field properties and data state after the standard logic runs.
Use the standard MDG feeder as the base, redefine only the methods where behavior changes, read the application context once, keep GET_DATA deterministic, and call super unless you intentionally override standard behavior. For search GUIBBs, normalize criteria in PROCESS_EVENT before delegating to super; for form/list feeders, adjust field properties and data state after the standard logic runs.
SAP MDG feeder customization is typically done by subclassing the standard feeder and redefining only the methods where behavior diverges. The source patterns show three key techniques: normalize search criteria in PROCESS_EVENT, adjust field properties in GET_FIELD_UI_PROP based on application context, and keep GET_DATA deterministic by reading the MDG context once, reusing values, and setting the changed flags correctly.
Process flow
- Subclass the standard MDG feeder class used by your GUIBB.
- Redefine only the relevant interface methods: `GET_DATA`, `GET_FIELD_UI_PROP`, `PROCESS_EVENT`, or `GET_DEFINITION`.
- In `GET_DATA`, call `super->if_fpm_guibb_form~get_data(...)` or the relevant superclass method first.
- Read `CL_USMD_APP_CONTEXT=>GET_CONTEXT` once and extract CR attributes if the context is bound.
- Use the CR/process values to decide whether field behavior or event normalization should run.
- For form/list behavior, update only the targeted entries in `CT_FIELD_USAGE` and set `EV_FIELD_USAGE_CHANGED` when needed.
- For search behavior, copy `IT_FPM_SEARCH_CRITERIA`, normalize the required criteria, then pass the modified table to `super->if_fpm_guibb_search~process_event(...)`.
- Keep `GET_DEFINITION` as a pass-through unless you must change catalog or action metadata.
Referenced tables
| Object | Purpose |
|---|---|
USMD120C | Read the change request header when `USMD_CREQUEST` is available from the MDG application context |
The remaining configuration, implementation details, and testing guidance continue from this answer more…
Related questions and keywords
Alternative questions
- How can I customize an MDG feeder class using redefined methods?
- What is the standard pattern for SAP MDG FPM feeder enhancements?
- How do I change field behavior and event handling in an MDG GUIBB feeder?
Possible questions
- How do I implement custom MDG FPM feeder logic in redefined GET_DATA, GET_FIELD_UI_PROP, PROCESS_EVENT, and GET_DEFINITION methods?
- How can I customize an MDG feeder class using redefined methods?
- What is the standard pattern for SAP MDG FPM feeder enhancements?
- How do I change field behavior and event handling in an MDG GUIBB feeder?
- Which context values should I read before changing MDG UI behavior?
- How do I normalize search criteria in PROCESS_EVENT for an MDG search GUIBB?