Please enable JavaScript.

Coggle requires JavaScript to display documents.

Dynamic Programming (16.1 Field Symbols (16.1.6 Casting (performed…

- - - - Based on which column the user double-clicks, the ls_cell-columnname field will have that field name.
      - The ASSIGN COMPONENT OF statement will assign that field to <field> field symbol.
  - - - work with the individual components of a structure
        
        the field symbol should be fully typed
        
        TYPE
        
        LIKE
      - to point to any field or structure dynamically
        
        as a generic type using TYPE ANY addition
      - assign an internal table to the field symbol
        
        TYPE STANDARD TABLE OF
      - assign any internal table dynamically
        
        ANY TABLE
  - - - statically
        
        DATA st_mara TYPE mara. FIELD-SYMBOLS: <fs_mara> TYPE mara. ASSIGN st_mara To <fs_mara>.
      - dynamically
        
        ASSIGN (name) TO <fs>.
        
        DATA field_name TYPE string. FIELD-SYMBOLS <fs_field> TYPE ANY. SELECT SINGLE ... FROM ... INTO field_name WHERE ... ASSIGN (field_name) TO <fs_field>.
        
        If the assignment is successful, the sy-subrc system field will be set to 0.
        
        When using dynamic assignments, it's important to check if the field symbol is assigned before accessing the field symbol.
        
        assignment for the attributes of a class
        
        ASSIGN oref->(attribute_name) TO <fs>.
        
        accessing a static attribute
        
        ASSIGN (class_name)=>(attribute_name) TO <fs>.
        
        both the class name and the attribute name dynamically
        
        ASSIGN (class_name)=>attribute TO <fs>.
        
        addresses the class name dynamically and the attribute name statically
        
        assign the components of a structure
        
        ASSIGN comp OF STRUCTURE struc TO <fs>.
        
        If the comp data object is set as TYPE c or TYPE string, then the content of the comp field is interpreted to be the component name.
        
        DATA: st_mara TYPE mara, l_field TYPE string VALUE 'MATNR'. FIELD-SYMBOLS: <fs_any> TYPE any. ASSIGN l_field OF STRUCTURE st_mara TO <fs_any>.
        
        If the comp data object is of a different type and has a number, then the system will interpret it as a field position and assign that field to the field symbol.
      - The internal table record is assigned to the field symbol using the ASSIGNING addition with the LOOP or READ statement
        
        READ TABLE itab ASSIGNING <fs> ... LOOP AT itab ASSIGNING <fs> .. ENDLOOP.
  - - - UNASSIGN <fs>.
  - - - implicitly
        
        the field symbol is fully typed or is typed generically using one of the buit-in ABAP types (c, n, p, or x)
      - explicitly
        
        the field symbol is typed genrically
        
        ASSIGN dobj TO <fs> CASTING [TYPE data_type | LIKE dobj].
- - - - uses the data type reference
    - - uses the data object reference
        
        The data reference variables are fully typed and can point to data objects of this type.
    - - defined as a generic type, DATA
        
        can point to any data object
    - - the reference variable should be dereferenced using the ->* dereference selector
        
        DATA v_matnr TYPE matnr VALUE '100'. DATA dref TYPE REF TO matnr. GET REFERENCE OF v_matnr INTO dref. WRITE dref->*.
  - - - DATA v_matnr TYPE matnr VALUE '100'. DATA dref TYPE REF TO matnr. DATA dref1 TYPE REF TO matnr. FIELD-SYMBOLS <fs> TYPE matnr. ASSIGN v_matnr TO <fs>.
        
        getting reference from data object
        
        GET REFERENCE OF v_matnr INTO dref.
        
        getting reference from derefernced reference variable
        
        GET REFERENCE OF dref->* INTO dref1.
        
        getting reference from field symbol
        
        GET REFERENCE OF <fs> INTO dref1.
    - - DATA v_matnr TYPE matnr VALUE '100'. DATA dref TYPE REF TO data. FIELD-SYMBOLS <fs> TYPE any. GET REFERENCE OF v_matnr INTO dref. ASSIGN dref->* TO <fs>. WRITE <fs>.
        
        because the dref reference variable is a generic type, we can't access the conts of v_matnr by directly dereferencing the reference variable. WRITE dref->* results in a syntax error.
  - - - creates an anonymous data object and assign the reference of the data object to the reference variable
        
        Anonymous data objects can't be accessed directly by their names. The data object needs to be dereferenced to access its contents.
        
        FIELD-SYMBOLS <fs> TYPE DATA. DATA dref TYPE REF TO DATA. CREATE DATA dref TYPE i. ASSIGN dref->* TO <fs>. <fs>=5.
        
        NEW statement
        
        FIELD-SYMBOLS <fs> TYPE DATA. DATA dref TYPE REF TO DATA. dref = NEW i(5). ASSIGN dref->* TO <fs>.
        
        access components of the anonymous data object
        
        TYPES: BEGIN OF ty_mara, matnr TYPE matnr, matart TYPE matart, END OF ty_mara. DATA dref TYPE REF TO ty_mara. CREATE DATA dref. dref -> matnr = '100'.
    - - specified dynamically
      - name is a data object that contains the data type
  - - - the target reference variable is a generic type and the source reference variable is fully typed
        
        TYPES: BEGIN OF ty_mara, matnr TYPE matnr, mtart TYPE matart, END OF ty_mara. DATA: dref TYPE REF TO ty_mara. '' Fully typed dref1 TYPE REF TO DATA. '' Generic typed CREATE DATA dref. dref1 = dref. '' Upcast
    - - the source reference variable is more general than the static type of the target reference variable
        
        TYPES: BEGIN OF ty_mara, matnr TYPE matnr, mtart TYPE mtart, END OF ty_mara. DATA: s_mara TYPE ty_mara, dref TYPE REF TO ty_mara. '' Fully typed dref1 TYPE REF TO DATA. '' Generic typed CREATE DATA dref. GET REFERENCE OF s_mara INTO dref1. TRY. dref ?= dref1. '' Down cast CATCH cx_sy_move_cast_error. ENDTRY.