Get the Change log for ALV line items

Question

Hello Experts,
I am using editable ALV table to display/change data. When user modifies data from ALV line items manually (direct entry), this change is recorded in get_context_change_log method of context node. Also in the screen I have one button, on click of this button I do some calculation for selected line items in action method and update the context node with new values. But with this second approach (button action) though values gets changed this is not recorded in to get_context_change_log of context node. I tried to use method add_context_attribute_change  in button action method to add attribute changes to change log tabel but it's not adding entries to change log. Does method add_context_attribute_change only works with OVS search helps and freely programmed value helps? And is there any other way for capturing changes(done by using action method and not manually) for ALV line items?
Thanks & Regards
Jayant

Answer 1

Here is code:
METHOD.
This method is in component controller, which gets called from View Action method (on click * of button).
  FIELD-SYMBOLS:<lfs> TYPE  Data.
*Data Declaration
  DATA lo_nd_cn_apc_item TYPE REF TO if_wd_context_node.
  DATA lit_apc_item TYPE wd_this->elements_cn_apc_item.
  DATA lo_el_cn_apc_item TYPE REF TO if_wd_context_element.
  data: l_component type ref to if_wd_component,
        l_context type ref to if_wd_context,
        lfd_added type abap_bool.
  CLEAR:lo_nd_cn_apc_item,lo_el_cn_apc_item.
  navigate from <CONTEXT> to <CN_APC_ITEM> via lead selection
  lo_nd_cn_apc_item = wd_context->get_child_node( name = wd_this->wdctx_cn_apc_item ).
  REFRESH:lit_apc_item.
  @TODO handle non existant child
  IF lo_nd_cn_apc_item IS NOT INITIAL.
    lo_nd_cn_apc_item->get_static_attributes_table( IMPORTING table = lit_apc_item ).
get element via lead selection
    lo_el_cn_apc_item = lo_nd_cn_apc_item->get_element( ).
  ENDIF.
        l_component = wd_this->wd_get_api( ).
        l_context = l_component->get_context( ).
Calculate Cost
  LOOP AT lit_apc_item ASSIGNING  <lfs>.
        <lfs>-cal_amount = ( <lfs>-cost_percent * <lfs>-sec_amount ) / 100.
        lfd_added = l_context->add_context_attribute_change(
            element              = lo_el_cn_apc_item
            attribute_name       = 'CAL_AMOUNT'
            new_value            = <lfs>-cal_amount
  ENDLOOP.
Bind Table.
  lo_nd_cn_apc_item->bind_table( new_items = lit_apc_item set_initial_elements = abap_true ).
ENDMETHOD.