动态创建Deep Structure的内表

使用cl_alv_table_create=>create_dynamic_table动态创建内表的时候，如果是Deep Structure的结构的内表，程序Dump.

 

可以使用另外一个方法(RTTI)来创建：

 

DATA:  CL_STRU    TYPE REF TO CL_ABAP_STRUCTDESCR,
       CL_TABL    TYPE REF TO CL_ABAP_TABLEDESCR,
       CL_HANDLE  TYPE REF TO DATA,
       COMPDESC   TYPE ABAP_COMPONENTDESCR,
       COMPONENTS TYPE ABAP_COMPONENT_TAB.
DATA:  CELLSTAB   TYPE LVC_T_STYL,
       CELLS      TYPE LVC_S_STYL.
FIELD-SYMBOLS:     TYPE STANDARD TABLE ,
                  TYPE ANY,
               TYPE LVC_T_STYL.

 

START-OF-SELECTION.
  CLEAR: COMPDESC.
  COMPDESC-TYPE ?= CL_ABAP_DATADESCR=>DESCRIBE_BY_NAME( 'EKPO-MATNR' ).
  COMPDESC-NAME  = 'MATNR'.
  APPEND COMPDESC TO COMPONENTS.
  COMPDESC-TYPE ?= CL_ABAP_DATADESCR=>DESCRIBE_BY_NAME( 'EKPO-MENGE' ).
  COMPDESC-NAME  = 'MENGE'.
  APPEND COMPDESC TO COMPONENTS.
  COMPDESC-TYPE ?= CL_ABAP_TYPEDESCR=>DESCRIBE_BY_DATA( CELLSTAB ).
  COMPDESC-NAME  = 'CELLSTAB'.
  APPEND COMPDESC TO COMPONENTS.

 

  CL_STRU  = CL_ABAP_STRUCTDESCR=>CREATE( COMPONENTS ).
  CL_TABL      = CL_ABAP_TABLEDESCR=>CREATE( CL_STRU ).
  CREATE DATA CL_HANDLE TYPE HANDLE CL_TABL.
  ASSIGN CL_HANDLE->* TO .

 

  SELECT * FROM ekpo INTO CORRESPONDING FIELDS OF TABLE
    UP TO 10 ROWS .

 

  CELLS-FIELDNAME = 'MENGE'.
  CELLS-STYLE     = CL_GUI_ALV_GRID=>MC_STYLE_ENABLED.
  INSERT CELLS INTO TABLE CELLSTAB.

 

  LOOP AT ASSIGNING .
    ASSIGN COMPONENT 'CELLSTAB' OF STRUCTURE TO .
    = CELLSTAB.
  ENDLOOP.

  ....
  ....
  ....

 

 

参考资料【转自Chris1919】

ABAP中的动态编程(1): Run Time Type Services(RTTS)
ABAP的RTTS主要通过一些type classes来实现，包括RTTC(Run Time Type Creation)和RTTI(Run Time Type Identification)功能。需要注意的是ABAP不能在运行时修改type，不像主流动态编程语言(Python、Ruby...)那样。下面是这些type classes的继承关系。

CL_ABAP_TYPEDESCR
  |
  |--CL_ABAP_DATADESCR
  |   |
  |   |--CL_ABAP_ELEMDESCR
  |   |--CL_ABAP_REFDESCR
  |   |--CL_ABAP_COMPLEXDESCR
  |       |
  |       |-- CL_ABAP_STRUCTDESCR
  |       |--CL_ABAP_TABLEDESCR
  |
  |--CL_ABAP_OBJECTDESCR
     |
     |--CL_ABAP_CLASSDESCR
     |--CL_ABAP_INTFDESCR

看到这个图的时候需要对ABAP的type system有一些了解。ABAP的type system正是分成data type和object type，然后data type又分成elementary type、reference type和complex type。这些在ABAP的帮助文档里面都有详述。简单的看几个RTTS的例子吧。

1. 获取一个structure的所有fields:

DATA:
  lo_struct TYPE REF TO cl_abap_structdescr,
  lt_comptab TYPE cl_abap_structdescr=>component_table,
  ls_flight TYPE sflight.
FIELD-SYMBOLS:
  TYPE cl_abap_structdescr=>component.

lo_struct ?= cl_abap_structdescr=>describe_by_data( ls_flight ).
lt_comptab = lo_struct->get_components( ).

LOOP AT lt_comptab ASSIGNING .
  WRITE -name.
ENDLOOP.

2. 创建一个structure:
TYPES: BEGIN OF s_field,
  name TYPE fieldname,
  dataelement TYPE field_type,
END OF s_field.

DATA:
  lo_descr TYPE REF TO cl_abap_typedescr,
  lt_comptab TYPE cl_abap_structdescr=>component_table,
  ls_compfld TYPE cl_abap_structdescr=>component,
  lo_struct TYPE REF TO cl_abap_structdescr,
  ls_field TYPE s_field,
  lt_field TYPE TABLE OF s_field,
  lr_data TYPE REF TO data.
FIELD-SYMBOLS:
  TYPE data,
  TYPE data.

ls_field-name = 'CARRID'.
ls_field-dataelement = 'S_CARR_ID'.
APPEND ls_field TO lt_field.
ls_field-name = 'CONNID'.
ls_field-dataelement = 'S_CONN_ID'.
APPEND ls_field TO lt_field.

LOOP AT lt_field INTO ls_field.

  CALL METHOD cl_abap_elemdescr=>describe_by_name
    EXPORTING
      p_name         = ls_field-dataelement
    RECEIVING
      p_descr_ref    = lo_descr
    EXCEPTIONS
      type_not_found = 1
      OTHERS         = 2.
  IF sy-subrc <> 0.
    CONTINUE.
  ENDIF.

  CLEAR ls_compfld.
  ls_compfld-name = ls_field-name.
  ls_compfld-type ?= lo_descr.
  APPEND ls_compfld TO lt_comptab.

ENDLOOP.

*create a structure
lo_struct = cl_abap_structdescr=>create( p_components = lt_comptab ).
*create data using the stucture
CREATE DATA lr_data TYPE HANDLE lo_struct.
ASSIGN lr_data->* to .
ASSIGN COMPONENT 'CARRID' OF STRUCTURE to .
*assgin value to CARRID field
= 'AAA'.
WRITE .