Creating timer problem in oracle forms

Question

Hello,
        I am using oracle weblogic 10.3.5 with oracle forms 11g at windows 7.I am trying to make a trigger but getting frm 40738 argument 1 to builtin GET_APPLICATION_PROPERTY cant be null error. I am using code at when-new-form-Instance trigger:
declare
    timer_id TIMER;
    one_second number:=1000;
    st varchar2(100);
begin
    timer_id :=find_timer('CLOCK_TIMER');
    If not id_null(timer_id) then
        delete_timer('timer_id');
    else
        timer_id := CREATE_TIMER('CLOCK_TIMER',one_second,REPEAT);
        --timer_id:=create_timer('CLOCK_TIMER',one_second,repeat);
        st:=Get_application_property(TIMER_NAME);
        message(st);
        end if;
        select to_char(sysdate,'HH24:MI:SS') into :EVENTS.CURRENT_TIME from dual;
        exception when others then
        message(TO_CHAR(SQLCODE)||''||SQLERRM);       
    end;
and at  When-Timer-Expired trigger:
declare
    timer_name varchar2(30);
BEGIN
   timer_name := GET_APPLICATION_PROPERTY(TIMER_NAME);
IF  timer_name = 'CLOCK_TIMER' THEN
      SELECT  TO_CHAR(SYSDATE,'HH24:MI:SS')
      INTO   :EVENTS.CURRENT_TIME
      FROM   DUAL;
END IF;
   EXCEPTION WHEN OTHERS THEN
      MESSAGE(TO_CHAR(SQLCODE)||''||SQLERRM);
END;
        Thank You
regards
aaditya.

Answer 1

The problem is that you have a local variable with the same name as the CONSTANT "TIMER_NAME".  Therefore, your call to GET_APPLICATION_NAME is passing the value of your Local Variable to the built-in instead of the value of the CONSTANT 'TIMER_NAME."
declare
    timer_name varchar2(30);
BEGIN
   timer_name := GET_APPLICATION_PROPERTY(TIMER_NAME);
IF  timer_name = 'CLOCK_TIMER' THEN
Change your code so your variable TIMER_NAME is unique (different) from the constant TIMER_NAME variable. A common programming standard prefix your variable names with the data time.  Following this concept, rename your variable to V_TIMER_NAME.
Craig...