When dealing with standard HCM Fiori Applications, it can be handy to provide custom error messages when adding additional checks. This can easily be done using the message container.
DATA(lo_message_container) = mo_context->get_message_container( ).
lo_message_container->add_messages_from_bapi( it_bapi_messages = VALUE #( ( type = 'E' message = 'This is a custom error.' ) )
iv_determine_leading_msg = /iwbep/if_message_container=>gcs_leading_msg_search_option-last
iv_add_to_response_header = abap_true ).
RAISE EXCEPTION NEW /iwbep/cx_mgw_busi_exception( ).
