New to ABAP Objects. Need help using events

Question

Hi all,
I got a program from one of the text books which has the output as
         pursur helps pilot
         stewardess helps passenger on seat 11
         stewardess helps passenger on seat 17
I am trying to modify this program to get an output:
purser helps pilot
stewardess helps passenger on seat 11 to have 2 foodservice.
stewardess helps passenger on seat 11 to have 2 drinkservice.
stewardess helps passenger on seat 17
stewardess helps passenger on seat 17 to have 1 foodservice.
stewardess helps passenger on seat 17 to have 1 drinkservice.
stewardess helps passenger on seat 21
stewardess helps passenger on seat 21 to have 3 foodservice.
stewardess helps passenger on seat 21 to have 3 drinkservice.
stewardess helps passenger on seat 25
stewardess helps passenger on seat 25 to have 1 foodservice.
stewardess helps passenger on seat 25 to have 1 drinkservice.
stewardess helps passenger on seat 31
stewardess helps passenger on seat 31 to have 2 foodservice.
stewardess helps passenger on seat 31 to have 2 drinkservice.
I have modified the program and am getting some errors. The program is:
REPORT  Z_KMADHUR_PROGRAM5.
class declarations.
class pilot definition.
public section.
methods: call_flight_attendant.
EVENTS: call_button_presses.
endclass.
class passenger definition.
public section.
methods: constructor importing value(i_seatnumber) type i,
         service_number importing value(i_servicenumber) type i,
         service_type importing value(i_servicetype) type i,
         call_for_help.
EVENTS: call_button_pressed exporting value(e_seatnumber) type i,
        call_service_number exporting value(e_servicenumber) type i,
        call_service_type exporting value(e_servicetype) type i.
PROTECTED SECTION.
data seatnumber type i.
data servicenumber type i.
data servicetype type i.
endclass.
class flight_attendant DEFINITION.
PUBLIC SECTION.
METHODS: constructor
         importing i_id type string,
         help_the_pilot for EVENT
         call_button_presses OF pilot,
         help_a_passenger FOR EVENT
         call_button_pressed OF passenger
         IMPORTING e_seatnumber, e_wervicenumber, e_servicetype.
         PROTECTED SECTION.
DATA id TYPE string.
ENDCLASS.
class Implementations
class pilot implementation.
method call_flight_attendant.
RAISE EVENT call_button_presses.
ENDMETHOD.
ENDCLASS.
         class passenger implementation.
         method: constructor.
         seatnumber = i_seatnumber.
         servicenumber = servicenumber.
         servicetype = servicetype.
         endmethod.
         method: call_for_help.
                  RAISE EVENT: call_button_pressed
                  EXPORTING e_seatnumber = seatnumber,
                  RAISE EVENT call_service_number
                  exporting e_servicenumber = servicenumber,
                  RAISE EVENT call_service_type
                  exporting e_servicetype = servicetype.
                  endmethod.
                  endclass.
class flight_attendant implementation.
method constructor.
id = i_id.
endmethod.
method help_the_pilot.
write: / id, 'helps pilot'.
endmethod.
method: help_a_passenger.
write: / id, 'helps passenger on seat',
e_seatnumber.
write:  'to have', e_servicenumber.
write: e_servicetype.
endmethod.
endclass.
global data
DATA: o_pilot type ref to pilot,
      o_passenger_1 type ref to passenger,
      o_passenger_2 type ref to passenger,
      o_passenger_3 type ref to passenger,
      o_passenger_4 type ref to passenger,
      o_passenger_5 type ref to passenger.
DATA: o_purser type ref to flight_attendant,
      o_stewardess type REF to flight_attendant,
      0_foodservice type REF to flight_attendant.
      0_drinkservice type REF to flight_attendant.
classical processing blocks
      start-of-selection.
      create object: o_pilot,
      o_passenger_1 exporting i_seatnumber = 11,
      o_passenger_2 exporting i_seatnumber = 17,
      o_passenger_2 exporting i_seatnumber = 21,
      o_passenger_2 exporting i_seatnumber = 25,
      o_passenger_2 exporting i_seatnumber = 31.
create object: o_purser
               exporting i_id = 'purser',
               o_stewardess
               exporting i_id = 'stewardess',
               o_foodservice
               exporting i_id = 'foodservice',
               o_drinkservice
               exporting i_id = 'drinkservice'.
set handler: o_purser->help_the_pilot for o_pilot,
             o_stewardess->help_a_passenger for all instances.
call method: o_pilot->call_flight_attendant,
o_passenger_1->call_for_help,
o_passenger_2->call_for_help.
I am getting an error "object type passenger doesnot have an event RAISE".
Any help is appreciated.
Thanks in advance
Thanks..

Answer 1

Hi Madhuri,
the error that you are getting 'statement is not accessible' is just because u didnt end the data statements with '.'...it is ','...check that
one more thing when you are creating the object passenger you have to export the 'service number' and the 'service type' also along with 'seatnumber' as you have declared that way in the constructor.
i made the changes...please check the code..there are no errors but please pass suitable values according to your requirement. right now all the events are getting triggered.
check this changed code..code in bold
*& Report  ZTEST_EVENTS
REPORT  ZTEST_EVENTS.
class declarations.
CLASS PILOT DEFINITION.
  PUBLIC SECTION.
    METHODS: CALL_FLIGHT_ATTENDANT.
    EVENTS: CALL_BUTTON_PRESSES.
ENDCLASS.                    "pilot DEFINITION
      CLASS passenger DEFINITION
CLASS PASSENGER DEFINITION.
  PUBLIC SECTION.
    METHODS: CONSTRUCTOR IMPORTING VALUE(I_SEATNUMBER) TYPE I
                                  VALUE(I_SERVICENUMBER) TYPE I
                                     VALUE(I_SERVICETYPE) TYPE I,
    CALL_FOR_HELP.
    EVENTS: CALL_BUTTON_PRESSED EXPORTING VALUE(E_SEATNUMBER) TYPE I,
    CALL_SERVICE_NUMBER EXPORTING VALUE(E_SERVICENUMBER) TYPE I,
    CALL_SERVICE_TYPE EXPORTING VALUE(E_SERVICETYPE) TYPE I.
  PROTECTED SECTION.
    DATA SEATNUMBER TYPE I.
    DATA SERVICENUMBER TYPE I.
    DATA SERVICETYPE TYPE I.
ENDCLASS.                    "passenger DEFINITION
      CLASS flight_attendant DEFINITION
CLASS FLIGHT_ATTENDANT DEFINITION.
  PUBLIC SECTION.
    METHODS: CONSTRUCTOR
    IMPORTING I_ID TYPE STRING,
    HELP_THE_PILOT FOR EVENT
    CALL_BUTTON_PRESSES OF PILOT,
    HELP_A_PASSENGER FOR EVENT
    CALL_BUTTON_PRESSED OF PASSENGER
    IMPORTING E_SEATNUMBER,
<b>    CALL_SERVICE_PRESSED FOR EVENT
    CALL_SERVICE_NUMBER OF PASSENGER
    IMPORTING E_SERVICENUMBER,
    CALL_TYPE_PRESSED FOR EVENT
    CALL_SERVICE_TYPE OF PASSENGER
    IMPORTING  E_SERVICETYPE.</b>
  PROTECTED SECTION.
    DATA ID TYPE STRING.
ENDCLASS.                    "flight_attendant DEFINITION
class Implementations
CLASS PILOT IMPLEMENTATION.
  METHOD CALL_FLIGHT_ATTENDANT.
    RAISE EVENT CALL_BUTTON_PRESSES.
  ENDMETHOD.                    "call_flight_attendant
ENDCLASS.                    "pilot IMPLEMENTATION
      CLASS passenger IMPLEMENTATION
CLASS PASSENGER IMPLEMENTATION.
  METHOD: CONSTRUCTOR.
    SEATNUMBER = I_SEATNUMBER.
    SERVICENUMBER = I_SERVICENUMBER.
    SERVICETYPE = I_SERVICETYPE.
  ENDMETHOD.                    "constructor
  METHOD: CALL_FOR_HELP.
    RAISE EVENT: CALL_BUTTON_PRESSED
    EXPORTING E_SEATNUMBER = SEATNUMBER.
<b>    RAISE EVENT: CALL_SERVICE_NUMBER
    EXPORTING E_SERVICENUMBER = SERVICENUMBER.
    RAISE EVENT: CALL_SERVICE_TYPE
    EXPORTING E_SERVICETYPE = SERVICETYPE.</b>
  ENDMETHOD.                    "call_type_help
ENDCLASS.                    "passenger IMPLEMENTATION
      CLASS flight_attendant IMPLEMENTATION
CLASS FLIGHT_ATTENDANT IMPLEMENTATION.
  METHOD CONSTRUCTOR.
    ID = I_ID.
  ENDMETHOD.                    "constructor
  METHOD HELP_THE_PILOT.
    WRITE: / ID, 'helps pilot'.
  ENDMETHOD.                    "help_the_pilot
  METHOD: HELP_A_PASSENGER.
    WRITE: / ID, 'helps passenger on seat',
    E_SEATNUMBER.
  ENDMETHOD.                    "help_a_passenger
<b>  METHOD CALL_SERVICE_PRESSED.
    WRITE: 'to have serviceno', E_SERVICENUMBER.
  ENDMETHOD.                    "call_service_pressed
  METHOD CALL_TYPE_PRESSED..
    WRITE: 'service type' ,E_SERVICETYPE.
  ENDMETHOD.</b>                    "call_type_pressed
ENDCLASS.                    "flight_attendant IMPLEMENTATION
global data
DATA: O_PILOT TYPE REF TO PILOT,
O_PASSENGER_1 TYPE REF TO PASSENGER,
O_PASSENGER_2 TYPE REF TO PASSENGER,
O_PASSENGER_3 TYPE REF TO PASSENGER,
O_PASSENGER_4 TYPE REF TO PASSENGER,
O_PASSENGER_5 TYPE REF TO PASSENGER.
DATA: O_PURSER TYPE REF TO FLIGHT_ATTENDANT,
O_STEWARDESS TYPE REF TO FLIGHT_ATTENDANT,
O_FOODSERVICE TYPE REF TO FLIGHT_ATTENDANT,
O_DRINKSERVICE TYPE REF TO FLIGHT_ATTENDANT.
classical processing blocks
START-OF-SELECTION.
  CREATE OBJECT: O_PILOT,
  O_PASSENGER_1 EXPORTING I_SEATNUMBER = 11
                          I_SERVICENUMBER = 12
                          I_SERVICETYPE = 13,
   O_PASSENGER_2 EXPORTING I_SEATNUMBER = 14
                          I_SERVICENUMBER = 15
                          I_SERVICETYPE = 16,
   O_PASSENGER_3 EXPORTING I_SEATNUMBER = 17
                          I_SERVICENUMBER = 18
                          I_SERVICETYPE = 19,
   O_PASSENGER_4 EXPORTING I_SEATNUMBER = 20
                          I_SERVICENUMBER = 21
                          I_SERVICETYPE = 22,
O_PASSENGER_5 EXPORTING I_SEATNUMBER = 23
                          I_SERVICENUMBER = 24
                          I_SERVICETYPE = 25.
*o_passenger_2 exporting i_seatnumber = 17,
*o_passenger_2 exporting i_seatnumber = 21,
*o_passenger_2 exporting i_seatnumber = 25,
*o_passenger_2 exporting i_seatnumber = 31.
  CREATE OBJECT: O_PURSER
  EXPORTING I_ID = 'purser',
  O_STEWARDESS
  EXPORTING I_ID = 'stewardess',
  O_FOODSERVICE
  EXPORTING I_ID = 'foodservice',
  O_DRINKSERVICE
  EXPORTING I_ID = 'drinkservice'.
  SET HANDLER: O_PURSER->HELP_THE_PILOT FOR O_PILOT,
  O_STEWARDESS->HELP_A_PASSENGER FOR ALL INSTANCES,
<b> O_STEWARDESS->CALL_SERVICE_PRESSED FOR ALL INSTANCES,
  O_STEWARDESS->CALL_TYPE_PRESSED FOR ALL INSTANCES.</b>
  CALL METHOD: O_PILOT->CALL_FLIGHT_ATTENDANT,
  O_PASSENGER_1->CALL_FOR_HELP.
similarly call the methods for the other objects also.
Regards,
Vidya