The following source code describes the ITEM_AMOUNT determination that is configured in the Derive dependent data immediately after modification pattern.
METHOD /bobf/if_frw_determination~execute. DATA: lt_item_data TYPE bobf_t_ci_item. ls_item_data TYPE REF TO bobf_s_ci_item, " clear exporting parameter CLEAR: eo_message et_failed_key. " read the instance data of the item io_read->retrieve( EXPORTING iv_node = if_ci_bopf_customer_invoi_c=>sc_node-item it_key = it_key IMPORTING et_data = lt_item_data ). " loop over all instances LOOP AT lt_item_data REFERENCE INTO ls_item_data. " calculate new amount ls_item_data->net_amount = ls_item_data->quantity * ls_item_data->price_amount. " update data io_modify->update( EXPORTING iv_node = is_ctx-node_key iv_key = ls_item_data->key is_data = ls_item_data ). ENDLOOP. ENDMETHOD.