Access htmldb_application.g_f01 from Report Query ?

Question

I want to have a search functionality built into the report itself, so, was trying to create a sql report as:
select htmldb_item.hidden(1,null) empno,
htmldb_item.text(2,null) ename,
htmldb_item.select_list_from_query(3,null,'select distinct job, job from emp') job,
htmldb_item.popupkey_from_query(4,null,'select ename, empno from emp',10) mgr
from dual
union all
select empno, ename, job, mgr
from emp
where empno = NVL(htmldb_application.g_f01(1), empno)
and ename = NVL(htmldb_application.g_f02(1), ename)
However, this gives an error saying "ORA-06553: PLS-221: 'G_F01' is not a procedure or is undefined".
I changed the radio button to parse query at runtime only to ensure that the collection gets created first, but even then during runtime it gives the same error. I tried to create two reports (to try conditional display) the first report contain the union clause, and the second report just containing select * from emp where empno = htmldb_appl....
even this is giving error.
Is there anyway to achieve this functionality ?

Answer 1

Ok, I created hidden columns for :p1_empno, p1:ename, p1:job etc and in a submit process assigned them to the htmldb_application.g_f01, ...etc, and changed the query to
from emp where empno = nvl(:p1_empno, empno) and ....
this is working,
(a)Is there any better way to do it instead of creating these hidden columns.
(b)how can we toggle this htmldb_item.hidden, ..., row (search row) display ? clicking on an icon in the column header should either display this row and clicking it again should hide this row.