Strange issue on row selection in a wd_table

Question

Hi all gurus,
I'm working on an SRM 7 system, specifically on the WD Component /SAPSRM/WDC_CTR_DOTC_IT, view V_CTR_DODC_ITEMS.
In the view there's a table showing items of a contract; we created a custom button ("item deletion") which simply triggers a method that sets the field ZZ_DEL_IND value to 'X' for the selected line(s).
Here's the method code:
METHOD onactionzdelete .
  DATA lv_action              TYPE /sapsrm/pdo_action_type.
  DATA lo_transaction_context TYPE REF TO /sapsrm/cl_transaction_context.
* Get instance of transaction object
  lo_transaction_context ?= /sapsrm/cl_transaction_context=>/sapsrm/if_transaction_context~get_instance( ).
* Set action id
  lv_action = 'DELETE_ITEM'.
  lo_transaction_context->set_current_action( iv_current_action = lv_action ).
* start ZZDEL_IND management
  DATA : lon_ctr_item     TYPE REF TO if_wd_context_node.
  DATA : lt_elem_set      TYPE wdr_context_element_set.
  DATA : ls_element       TYPE REF TO if_wd_context_element.
  DATA : deleted          TYPE abap_bool.
  CALL METHOD wd_context->get_child_node
    EXPORTING
      name       = 'CTR_ITEM'
    RECEIVING
      child_node = lon_ctr_item.
* Get the selected elements of the item table
  lt_elem_set  = lon_ctr_item->get_selected_elements( abap_true ).
* for each selected element, set ZZ_DEL_IND value
* Get the static attributes of all SELECTED elements into an internal table
  LOOP AT lt_elem_set INTO ls_element.
    CALL METHOD ls_element->set_attribute
      EXPORTING
        value = abap_true
        name  = 'ZZ_DEL_IND'.
    CALL METHOD ls_element->set_changed_by_client
      EXPORTING
        flag = abap_true.
  ENDLOOP.
  CALL METHOD wd_comp_controller->mo_bom_ctr->/sapsrm/if_cll_bo_mapper~fire_event_refresh( ).
ENDMETHOD.
Now, the problem:
- if I select a single row and press the button, ZZ_DEL_IND is set correctly for the selected row;
- if I select all the positions using the standard button SELECT->SELECT ALL , ZZ_DEL_IND is set correctly for all the selected rows;
BUT...
- if I select more than a single position (holding CTRL key down), ZZ_DEL_IND is NOT set.
In debug, I've seen that the problems are in the fire_event_refresh( ), which in case of single selection or all positions selected triggers correctly an update process, while in case of multiple selection "by hand" does not.
In details: /sapsrm/if_cll_bo_mapper~fire_event_refresh triggers a method:
me->/sapsrm/if_cll_xo_mapper~fire_event_update( )
which itself launches the update process:
me->fire_event_update( IMPORTING ev_update_performed = ev_update_performed )
Here, the method extracts all the mappers for the WD and loops over them to check for something changed:
LOOP AT lt_mapper ASSIGNING <ls_mapper>.
      CLEAR: lv_exception_occured, lv_update_performed.
      IF <ls_mapper>-mapper->is_ui_changed_by_client( ) EQ abap_true.
And that's the problem; when processing the mapper -> (in debug), I can see that:
- when a single row is selected, or all the rows are selected via "SELECT ALL" standard method, then the mapper results changed by client (the above condition is then satisfied)...
- while in case of multiple selection , is_ui_changed_by_client( ) = abap_false.
Has anyone suggestions on how to overcome this problem? I guess it deals with multiple selection process.
Thanks in advance

Answer 1

I found something that seems useful here:
[http://help.sap.com/saphelp_nw70ehp2/helpdata/en/4b/5d0d7a7f142b5fe10000000a42189c/content.htm]
in particular, differences between the onSelect and onLeadSelect actions.
By default, the wd I'm working on has the following table events - action bindings::
onLeadSelect -> row_select
onSelect, as a consequence, empty.
I tried the following modification (yes, I know, it's "technically" a standard modification, anyway I'm doing some attempts to make things work):
onLeadSelect -> empty
onSelect -> onSelect (that's a std action defined in the WD... perhaps SAP provided both ways to let the customer choose?)
Anyway... Let's go for a good and a bad news:
- the good one: onSelect is triggered anytime an item position is selected, and triggers an event, so... seems THE solution.
- the bad one: it dumps :-D and here's the motive... this is the standard code of onSelect:
METHOD onactionon_select .
* Object reference
  DATA: loe_context_element   TYPE REF TO if_wd_context_element.
* Constants
  DATA: lc_context_element  TYPE string VALUE 'CONTEXT_ELEMENT'.
* Get context element
----> loe_context_element = wdevent->get_context_element( name = lc_context_element ). <-----
  loe_context_element->set_changed_by_client( ).
* Call mapper class' hadle approve hier item mehtod
  wd_this->mo_dodm_ctr_items->/sapsrm/if_cll_do_tree_mapper~handle_approve_hier_item( io_wd_event = wdevent ).
ENDMETHOD.
The problem is in the marked line, as wdevent has the parameter with name CONTEXT_ELEMENT set to INITIAL.
As a consequence, loe_context_element is initial and the set_changed_by_client() method dumps - OBJECTS_OBJREF_NOT_ASSIGNED_NO.
What am I doing wrong? I simply swapped from onLeadSelect use to onSelect one, using methods provided by the standard. Can anyone help on this point? Seems quite an interesting task
Edited by: Matteo Montalto on Feb 22, 2011 10:39 PM