Custom getter & setter methods in Webdynpro ABAP

Hello... Welcome

While developing complex WDA applications, we may have to have many context nodes defined and its very much required to get and set data from/to these context nodes.

For getting and setting data from/to a context node, we need to follow the below process

Define data of type node ( element/elements )
Get the node reference by using node names
Get the elements using node reference
Get data / set data using element reference or node reference based on cardinality i.e. if cardinality is 0...1, 1..1 ( structure ) 0..n, 1...n ( table )

If we have many nodes in our application, say around 10-15 context nodes, we have to repeat above steps for each read/write data access

So, its better idea to have a common method for getting data from context node / for setting data to context node.

HELPER CLASS:

You would be wondering why this HELPER CLASS is needed ?,

It very much helpful to have all common methods in a class and it can be called from any view/ controller method.Hence,it is named as helper class to my application.

I have created the below 2 static methods in class ZCL_WD_HELPER_CLASS

GET_CTX_STAT_ATTR( ) - Get static attributes / table data of context node
SET_CTX_STAT_ATTR( ) - Set static attributes / table to context node

Now, let us look at these methods signature & logic

Method: GET_CTX_STAT_ATTR( ).

Signature:

Logic:

GET_CTX_STAT_ATTR
METHOD get_ctx_stat_attr. DATA lo_nd TYPE REF TO if_wd_context_node. DATA lo_nd_struct_descr TYPE REF TO cl_abap_structdescr. DATA lo_nd_info TYPE REF TO if_wd_context_node_info. DATA lo_stat_data TYPE REF TO data. DATA lv_node_name TYPE string. DATA lv_type_name TYPE string. DATA lv_index TYPE i. DATA lo_typedescr_target TYPE REF TO cl_abap_typedescr. FIELD-SYMBOLS: <lt_stat_attr> TYPE STANDARD TABLE, <ls_stat_attr> TYPE any. "---------------------------------------------------- "Purpose: Get data from context node of given controller context "---------------------------------------------------- CLEAR: ed_error_message, ed_stat_attr. "=================================== "check if type of target is table lo_typedescr_target = cl_abap_typedescr=>describe_by_data( p_data = ed_stat_attr ). IF lo_typedescr_target IS NOT BOUND. RETURN. ENDIF. "check if context is supplied IF io_context IS BOUND. lv_node_name = id_node_name. TRANSLATE lv_node_name TO UPPER CASE. TRY. "read node lo_nd = io_context->get_child_node( name = lv_node_name ). IF lo_nd IS BOUND. " Return if node is not dirty, and caller wants values only if dirty IF ib_only_if_dirty = abap_true AND lo_nd->is_changed_by_client( ) = abap_false. RETURN. ENDIF. "get node info lo_nd_info = lo_nd->get_node_info( ). IF lo_nd_info IS BOUND. "get the type descriptor of node lo_nd_struct_descr = lo_nd_info->get_static_attributes_type( ). "check if type name is DDtype IF lo_nd_struct_descr IS BOUND AND lo_nd_struct_descr->is_ddic_type( ) EQ abap_true. lv_type_name = lo_nd_struct_descr->get_relative_name( ). "============================================ "based on node cardinality & supplied index, " create data type & get data from context IF lo_nd_info->is_multiple( ) EQ abap_true AND id_index = 0. "============================================ "return if target data type is not of kind - table IF lo_typedescr_target->kind NE lo_typedescr_target->kind_table. ed_error_message = 'Data mismatch against context node'. RETURN. ENDIF. "create data object based cardinality CREATE DATA lo_stat_data TYPE TABLE OF (lv_type_name). ASSIGN lo_stat_data->* TO <lt_stat_attr>. IF <lt_stat_attr> IS ASSIGNED. lo_nd->get_static_attributes_table( IMPORTING table = <lt_stat_attr> ). ed_stat_attr = <lt_stat_attr>. ENDIF. ELSE. "============================================ "return if target data type is not of kind - Structure IF lo_typedescr_target->kind NE lo_typedescr_target->kind_struct. ed_error_message = 'Data mismatch against context node'. RETURN. ENDIF. "Prepare lv_index, based on id_index IF id_index EQ 0. lv_index = 1. ELSE. lv_index = id_index. ENDIF. "create data object based cardinality CREATE DATA lo_stat_data TYPE (lv_type_name). ASSIGN lo_stat_data->* TO <ls_stat_attr>. IF <ls_stat_attr> IS ASSIGNED. lo_nd->get_static_attributes( EXPORTING index = lv_index IMPORTING static_attributes = <ls_stat_attr> ). ed_stat_attr = <ls_stat_attr>. ENDIF. ENDIF. ENDIF. ENDIF. ELSE. ed_error_message = 'Node does not exist in the provided context'. ENDIF. CATCH cx_root. "#EC CATCH_ALL ##no_handler ed_error_message = 'Error occured during context node read'. ENDTRY. ELSE. ed_error_message = 'Context is not supplied'. RETURN. ENDIF. ENDMETHOD.

GET_CTX_STAT_ATTR

METHOD get_ctx_stat_attr.
DATA lo_nd                TYPE REF TO if_wd_context_node.
DATA lo_nd_struct_descr   TYPE REF TO cl_abap_structdescr.
DATA lo_nd_info           TYPE REF TO if_wd_context_node_info.
DATA lo_stat_data         TYPE REF TO data.
DATA lv_node_name         TYPE string.
DATA lv_type_name         TYPE string.
DATA lv_index             TYPE i.
DATA lo_typedescr_target TYPE REF TO cl_abap_typedescr.

FIELD-SYMBOLS: <lt_stat_attr>     TYPE STANDARD TABLE,
                 <ls_stat_attr>     TYPE any.
"----------------------------------------------------
"Purpose: Get data from context node of given controller context
"----------------------------------------------------
CLEAR: ed_error_message,
          ed_stat_attr.

"===================================

"check if type of target is table
lo_typedescr_target =
cl_abap_typedescr=>describe_by_data( p_data = ed_stat_attr ).
IF lo_typedescr_target IS NOT BOUND.
RETURN.
ENDIF.

"check if context is supplied
IF io_context IS BOUND.
lv_node_name = id_node_name.
TRANSLATE lv_node_name TO UPPER CASE.

    TRY.
        "read node
        lo_nd = io_context->get_child_node( name = lv_node_name ).
        IF lo_nd IS BOUND.

          " Return if node is not dirty, and caller wants values only if dirty
          IF ib_only_if_dirty = abap_true AND
             lo_nd->is_changed_by_client( ) = abap_false.
            RETURN.
          ENDIF.

          "get node info
          lo_nd_info = lo_nd->get_node_info( ).
          IF lo_nd_info IS BOUND.

            "get the type descriptor of node
            lo_nd_struct_descr =
            lo_nd_info->get_static_attributes_type( ).
            "check if type name is DDtype
            IF lo_nd_struct_descr IS BOUND AND
               lo_nd_struct_descr->is_ddic_type( ) EQ abap_true.

lv_type_name = lo_nd_struct_descr->get_relative_name( ).

              "============================================
              "based on node cardinality & supplied index,
              " create data type & get data from context

IF lo_nd_info->is_multiple( ) EQ abap_true AND
id_index = 0.

"============================================
"return if target data type is not of kind - table

                IF lo_typedescr_target->kind NE
                    lo_typedescr_target->kind_table.
                  ed_error_message = 'Data mismatch against context node'.
                  RETURN.
                ENDIF.

"create data object based cardinality
CREATE DATA lo_stat_data TYPE TABLE OF (lv_type_name).

ASSIGN lo_stat_data->* TO <lt_stat_attr>.

                IF <lt_stat_attr> IS ASSIGNED.
                  lo_nd->get_static_attributes_table(
                   IMPORTING table = <lt_stat_attr> ).

                  ed_stat_attr = <lt_stat_attr>.
                ENDIF.
              ELSE.

                "============================================
                "return if target data type is not of kind - Structure
                IF lo_typedescr_target->kind NE
                    lo_typedescr_target->kind_struct.
                  ed_error_message = 'Data mismatch against context node'.
                  RETURN.
                ENDIF.

                "Prepare lv_index, based on id_index
                IF id_index EQ 0.
                  lv_index = 1.
                ELSE.
                  lv_index = id_index.
                ENDIF.

"create data object based cardinality
CREATE DATA lo_stat_data TYPE (lv_type_name).

ASSIGN lo_stat_data->* TO <ls_stat_attr>.

                IF <ls_stat_attr> IS ASSIGNED.
                  lo_nd->get_static_attributes(
                   EXPORTING index = lv_index
                   IMPORTING static_attributes = <ls_stat_attr> ).

                  ed_stat_attr = <ls_stat_attr>.
                ENDIF.
              ENDIF.
            ENDIF.
          ENDIF.
        ELSE.
          ed_error_message = 'Node does not exist in the provided context'.
        ENDIF.
      CATCH cx_root.                                     "#EC CATCH_ALL
        ##no_handler
        ed_error_message = 'Error occured during context node read'.
    ENDTRY.
ELSE.
    ed_error_message = 'Context is not supplied'.
    RETURN.
ENDIF.
ENDMETHOD.

Okay, now let us see how to use the method GET_CTX_STAT_ATTR( ) to get data from context node

Example:

Get data : Let us say we have a context node MY_NODE_T in component controller context with cardinality 0....n /1..n

DATA lt_my_node_t     TYPE wd_this->elements_my_node_t.  DATA lv_error_message TYPE string.  CALL METHOD zcl_wd_helper_class=>get_ctx_stat_attr    EXPORTING      io_context       = wd_context      id_node_name     = 'MY_NODE_T'
*     id_index         = 0
*     ib_only_if_dirty = ABAP_FALSE    IMPORTING      ed_stat_attr     = lt_my_node_t      ed_error_message = lv_error_message.

Get data : Let us say we have a context node MY_NODE_S in component controller context with cardinality 0....1 / 1...1

DATA ls_my_node_s     TYPE wd_this->element_my_node_s.  DATA lv_error_message TYPE string.  CALL METHOD zcl_wd_helper_class=>get_ctx_stat_attr    EXPORTING      io_context       = wd_context      id_node_name     = 'MY_NODE_S'
*     id_index         = 0
*     ib_only_if_dirty = ABAP_FALSE    IMPORTING      ed_stat_attr     = ls_my_node_s      ed_error_message = lv_error_message.

Continued.......

Custom getter & setter methods in Webdynpro ABAP - Part 2