Changing field usage in Feeder class for Lists

Hi,

We have a requirement to hide fields, and set as read only, and mandatory dynamically at run time on standard UIBBs.

To achieve this I am editing the GET_DATA method of the Feeder class and changing ct_field_usage. And then setting  ev_field_usage_changed = abap_true.

This seems to work well for the FEEDER_FORM classes but is not working on the FEEDER_LIST classes. For instance the Dimensions UIBB fields are not becoming read only.

I have debugged the code and seen that ct_field_usage for my fields is in fact being changed (to read only) but the UI is keeping these fields as editable.

What am I doing wrong?

Thanks in advance