Tracking ABAP web dynpro events in back end SAP

Question

Hi Experts ,
I have
Is there any way to capture the events on th ABAP web dynpro in the backend.
The scenario is that i have some particular code which gets executed in the back end when User clicks on any button or tab in the appraisal document , which is ABAP web dynpro application.
I want this code to be executed only when User clicks on particular TAB/BUTTON on the ABAP web dynpro.
Are there any system tables that I can check.I am novice in ABAP Web dynpro.
Thanks

Answer 1

hi ,
I wud like to demonstrate this with example
suppose in ur WD  screenu  take the sales organization as input .
and u want to do smthing like this in backend :
u wud like to read VBELN from VBAK where VKORG is with in sales organization range entered in input field
create a context attributeinside a context node  in Context Tab inside ur view
first bind the VALUE property of ur Input field to a context attribute
inside the method OnActionClick  thn u wud  use code wizard (control +f7) to read the context attribute which is binded to input field
u press CONTROL + F7 and select the radio button read context node/attribute
DATA lo_nd_cn_node TYPE REF TO if_wd_context_node.
    DATA lo_el_cn_node TYPE REF TO if_wd_context_element.
    DATA ls_cn_node TYPE wd_this->element_cn_node .
    DATA lv_attr  LIKE ls_city-ca_attr.
*   navigate from <CONTEXT> to <CN_VISIBLE> via lead selection
    lo_nd_node = wd_context->get_child_node( name = wd_this->wdctx_ca_attr).
*   get element via lead selection
    lo_el_cn_node = lo_nd_cn_node->get_element(  ).
*   get single attribute
    lo_el_cn_node->get_attribute(
      EXPORTING
        name =  `CA_ATTR`
      IMPORTING
        value = lv_attr ).
// I have read attribute CA_ATTR inside the node CN_NODE
thn u wud put select query to fetch from data base using the value lv_attr
DATA : vbeln type string .
SELECT SINGLE vbeln FROM vbak INTO lv_vbeln
    WHERE vkorg = lv_attr .
I hope it is clear nw
regards,
amit