Error while extracting Employee details in Webdynpro application

Question

Hi,
I am using below codes to extract details from Employess in Method tab
wd_this->fire_to_alv_table_plg(  ).
  DATA lo_nd_employee TYPE REF TO if_wd_context_node.
  DATA lo_el_employee TYPE REF TO if_wd_context_element.
  DATA lt_employee TYPE wd_this->elements_employee.
  DATA ls_employee TYPE wd_this->element_employee.
navigate from <CONTEXT> to <EMPLOYEE> via lead selection
  lo_nd_employee = wd_context->get_child_node( name = wd_this->wdctx_employee ).
  DATA lo_el_context TYPE REF TO if_wd_context_element.
  DATA ls_context TYPE wd_this->element_context.
  DATA lv_emp_no LIKE ls_context-emp_no.
  DATA lv_num TYPE I.
get element via lead selection
  lo_el_context = wd_context->get_element(  ).
get single attribute
  lo_el_context->get_attribute(
    EXPORTING
      name =  `EMP_NO`
    IMPORTING
      value = lv_emp_no ).
  SELECT ZZORGEH ZZ_PER_ASSG BEGDA ENDDA INTO CORRESPONDING FIELDS OF TABLE
      lt_employee  FROM PA9027 WHERE PERNR EQ lv_emp_no AND ENDDA EQ '99991231'.        
  DESCRIBE TABLE lt_employee LINES lv_num.       
  lo_nd_employee->BIND_TABLE( lt_employee ).
  data lo_cmp_usage type ref to if_wd_component_usage.
  lo_cmp_usage =   wd_this->wd_cpuse_alv( ).
  if lo_cmp_usage->has_active_component( ) is initial.
    lo_cmp_usage->create_component( ).
  endif.
  DATA lo_INTERFACECONTROLLER TYPE REF TO IWCI_SALV_WD_TABLE .
  lo_INTERFACECONTROLLER =   wd_this->wd_cpifc_alv( ).
  DATA lo_value TYPE ref to cl_salv_wd_config_table.
  lo_value = lo_interfacecontroller->get_model( ).
Set Visible Row Count as 5
  lo_value->if_salv_wd_table_settings~set_visible_row_count( lv_num ).
The Config Table Setting to Display Table & Business Graphics
  DATA: l_ref_config_table TYPE REF TO if_salv_wd_table_settings,
        l_display_as TYPE salv_wd_constant VALUE '02'.
  l_ref_config_table ?= lo_value.
  l_ref_config_table->set_display_as( value = l_display_as ). 
endmethod.
It is giving me error saying Field "WDCTX_EMPLOYEE" is unknown. It is neither in one of the          
specified tables nor defined by a "DATA" statement . . . . . . . . . .          
Can u tell me where i am going wrong..
Thanks
Shan

Answer 1

Well wd_this->wdctx_employee is the generated constant to hold the name of your context node.  I would say that one of three things caused this error.
1.  You type the code (or cut and pasted it) and this context node name is spelled different or doesn't exist in the local context (maybe not copied from a component controller yet?).
2.  You haven't activated the component/view yet so the attribute hasn't been generated in the dynamic class.  Comment out the code, activate, then remove the comments.
3.  You had the context named employee and entered the code (or used the wizard to generate it).  Everything was fine.  Then you renamed the context - this would lead to breaking the code because the name changed and the constant no longer exists in the generated class.
Any way around this - check you context node name and make sure it matches what is referenced in the code.