Calling another BSP from a BSP using bsp:call having a Problem.

Question

Hi All,
I have a BSP (page1.bsp), within Page1.bsp I am calling another BSP (Page2.bsp)
But I need to Call Page2.bsp from Page1.bsp 'N' number of times depending upon an internal table, code is mentioned below ( Problem is mentioned after the code ) :
LOOP AT mr_plan_comparison->mt_selected_plans ASSIGNING <fs_selected_plan>.
     CLEAR lr_plan.
     lr_plan = zcl_zpr_s_model_pool=>load_new_plan( iv_plan_id = <fs_selected_plan>-plan_id ).
     lr_plan->mr_phases = lr_plan->get_phases( ).
     lt_phases_of_a_plan = mr_plan_comparison->mt_selected_phases.
     DELETE lt_phases_of_a_plan WHERE plan_id <> <fs_selected_plan>-plan_id.
     lr_plan->mr_phases->mt_phases = lt_phases_of_a_plan.
     lv_comp_id_str = zcl_zxa_str=>conc( iv_1 = sy-tabix
                                         iv_2 = 'xyz' ).
     CONDENSE lv_comp_id_str NO-GAPS.
  %>
  <tr>
  <td>
<htmlb:textView text="<b><%= zcl_zrm_s_data_manager=>get_name_from_id( iv_table_name = 'ZPR_PROGRAM'
                                                                     iv_field_name = 'PRG_ID'
                                                                     iv_field_value_id = <fs_selected_plan>-prg_id  ).%></b>" />
     <bsp:call   url     = "<%= zcl_zrm_co=>sc_bsp_rpphachart %>"
                 comp_id = "<%= lv_comp_id_str %>" >
<%-- same subcontroller n times: use different component IDs --%>
    <bsp:parameter name  = "mr_plan"                  value = "<%= lr_plan %>" />
    <bsp:parameter name  = "mr_plan->MR_PHASES"       value = "<%= lr_plan->mr_phases %>" />
    <bsp:parameter name  = "mv_show_current_version"  value = "<%= abap_true %>" />
    <bsp:parameter name  = "mv_show_version_nr"       value = "<%= SPACE %>" />
</bsp:call>
I am able to display the Page1.bsp with no problem having Page2.bsp as well on it,
But I have a radio button or a dropdown on Page2.bsp and when the event triggers it goes to the DO_HANDLE_EVENT of Page2.bsp whcih is correct but after DO_HANDLE_EVENT it does not go to DO_REQUEST of Page2.bsp and rather goes to Page1.bsp at the LOOP, by this what ever selection I did I am loosing those values.
What changes should I make so that after Do_HANDLE_EVENT of Page2.bsp it should call it's Do_Request?
I guess it might be related to the reference or something?
Regards,
Abhinav

Answer 1

Hi Abhinav,
the flow of nested controllers is as follows:
contr1->do_request (here dispatch_input triggers data and event handling)
  -->contr1->do_handle_data
  -->contr2_1->do_handle_data
  -->contr2_2->do_handle_data
  -->contr2_3->do_handle_data
..... for all controllers in the hierarchy
  -->contrXXX->do_handle_event (the controller instance where the event was triggered)
contr1->do_request continued
call view for contr1
  -->contr2_1->do_request
  -->contr2_2->do_request
  -->contr2_3->do_request
.... for all subcontrollers called by your logic
the dispatch_input in the subcontroller does not have any effect as within the method it is checked whether the controller is a root controller or not.
In case you call the subcontroller with the same component ID's than you called them before, the same instances are reused. So if you reuse the instances and set an attribute within the instance that handled the event you should be able to "remember" the values.
Another option is to write the event back either to the application class or to the parent controller (is available via attribute m_parent) and hand it back over to the controller during the calling loop.
Hope that helps.
Best Regards
Michael