Implementing a valuehelp using the GET_V for a DDLB

Pieter Rijlaarsdam, 25 August 2010

In the CRM webclient you implement or redefine the valuehelp logic. Sometimes a valuehelp is not implemented in the standard, or you might want to implement a more company-specific valuehelp. This can be done by redefining the GET_V of an attribute of a context node.

A GET_V for a DDLB (DropDown List Box) would particularly contain the following code:

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DATA: lt_ddlb TYPE bsp_wd_dropdown_table,

lr_ddlb TYPE REF TO cl_crm_uiu_ddlb.

lt_ddlb = cl_crm_uiu_bt_tools=>get_strcmp_ddlb(
iv_structure = [name of the structure the field is part of]

iv_component = [Fieldname])
.

IF NOT lr_ddlb IS BOUND.

CREATE OBJECT lr_ddlb EXPORTING iv_source_type = ‘T’.

ENDIF.

lr_ddlb->set_selection_table( it_selection_table = lt_ddlb ).

rv_valuehelp_descriptor = lr_ddlb.

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If you want the dropdown listbox to be occupied with values from a domain, you can use the following code:
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DATA:lt_ddlb TYPE bsp_wd_dropdown_table.
SELECT domvalue_l ddtext INTO TABLE lt_ddlb FROM dd07t WHERE
      domname = [domain] AND ddlanguage = sy-langu.

INSERT INITIAL LINE INTO lt_ddlb INDEX 1.
SORT lt_ddlb BY value.
IF sy-subrc = 0.
       CREATE OBJECT rv_valuehelp_descriptor TYPE cl_bsp_wd_valuehelp_pldescr
        EXPORTING
            iv_source_type = ‘T’
            iv_selection_table = lt_ddlb.
ENDIF.

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The values from the valuehelp are determined when building the screen (do_prepare_output). This means, that if you want the available values to vary based on the contents of another field, you only have to trigger a roundtrip to the server (like raising a server event, which can be implemented in the get_p) when the contents of the field which it depends on are changed.

Furthermore, you will have to implement in the get_v of the field how the available values are filtered.