[ABAP] Change Tax Code for Invoice Item

Solution 1.
Include: LMRMDF0H
Form: t_drseg_aufbauen_pruefen_1   at the end of form code I cleared position tax code in a loop:

ENHANCEMENT 1  ZMUK_MIRO_TAXCODE_EDIT. "active version
  FIELD-SYMBOLS <ls_drseg> LIKE LINE OF t_drseg[].
  LOOP AT t_drseg ASSIGNING <ls_drseg>.
  CLEAR <ls_drseg>-mwskz.
  ENDLOOP.
ENDENHANCEMENT.

After that, system is propagating tax code automatically from MIRO header to all the items.

* 如採用Solution1有可能在SAP升級後，標準程式恢復原版，客製的部分就會被蓋掉


Solution 2.
BAdI: EXTENSION_US_TAXES
Method: MM_ITEM_TAX_MODIFY

method IF_EX_EXTENSION_US_TAXES~MM_ITEM_TAX_MODIFY.

IF I_RBKPV-MWSKZ1 <> I_DRSEG-MWSKZ.   "header tax  <> item tax
  E_MWSKZ = I_RBKPV-MWSKZ1.                     "item tax = header tax
  E_CHANGE = 'X'.
ENDIF.

endmethod.

or

Function: MRM_BADI_TAX_DATA_CHANGE