Implementing multi-select lists in Oracle Forms

Question

Can anyone of you please tell me how to do multi select list in forms. I used picklist.fmb from oracle demo forms but it is not working fine. If someone could provide a working form I will be grateful to them.
My mail id is [email protected]

Answer 1

Some years ago I wrote (using Forms6i) utility MSLOV for such purposes, and even wrote an article about using it, but, of course, in Russian :-)
I successfully use it in my Web Forms6i project and also test it in C-S Forms6i and Forms9i.
If someone interesting, I also have short english usage description.
It will be nice to hear your comments.
At first, you need a code, which can be downloaded from http://www.geocities.com/luzanovp/mslov.html
At the end of article there is a link to mslov.zip. Get it.
Compile MSLOV.fmb and MSLOV.pll
Run demo forms: EMP_DEMO.fmb, ORD_DEMO.fmb and see how it works.
It requires Scott's tables: emp, dept, ord, item, product. You can create these tables from demobld.sql
Below description about how to use it.
You can show to user only one column, actually it can be expression (so, you
are not limited here to one database column only ).
Specify this column/expression by label_in parameter to fp_mslov.show_lov
For example, if EMP table contains first_name and last_name columns and
you want to show to the user full name do this:
IF fp_mslov.show_lov (
   label_in => 'first_name || '' '' || last_name',
Parameter id_in - this is what will be returned to you as a developer after user
made his choice.
For example, you want to receive array of EMPNO:
IF fp_mslov.show_lov (
   label_in => 'first_name || '' '' || last_name',
   id_in => 'empno'
In some cases you need to return more that one column.
You can specify up to five additional columns for such purposes.
For example, you want to return not only EMPNO, but also SAL and COMM columns:
IF fp_mslov.show_lov (
   label_in => 'first_name || '' '' || last_name',
   id_in => 'empno',
   col1_in => 'sal',
   col2_in => 'comm'
Also, you can use expressions in place of these columns:
   col3_in => 'sal + NVL(comm, 0)'
From which table we must query?
How to order by or specify some conditions(Where clause)?
Where the place for GROUP BY?
For all these questions you must use from_clause_in parameter.
In our example we will query emp table and want order by salary in descending
order:
IF fp_mslov.show_lov (
   from_clause_in => 'FROM emp ORDER BY sal DESC',
Parameter title_in to fp_mslov.show_lov is a self documented.
This is a title for MSLOV dialog.
So, to invoke mslov utility, we construct such call:
IF fp_mslov.show_lov (
   label_in => 'first_name || '' '' || last_name',
   id_in => 'empno',
   col1_in => 'sal',
   col2_in => 'comm'
   col3_in => 'sal + NVL(comm, 0)',
   from_clause_in => 'FROM emp ORDER BY sal DESC',
   title_in => 'Select employees'
THEN
This function fp_mslov.show_lov will return TRUE if user made selection and
FALSE if user press CANCEL (similar to SHOW_LOV builtin).
Now, if it return TRUE we need to process returned rows (selected by user).
I store it in global record group.
But to work with this record group, you can use fp_mslov package, which
provide desired API for this purpose.
At first, you need to declare a variable of FP_MSLOV.OUT_RECORD_TYPE type.
Actually this is a record type declared in fp_mslov package specification.
DECLARE
   returned_rec  FP_MSLOV.OUT_RECORD_TYPE;
To process selected rows we need a loop from 1 to a number of selected rows.
Such number can be received by fp_mslov.rowcount function:
FOR i IN 1 .. fp_mslov.rowcount
LOOP
END LOOP;
To return one row we can use fp_mslov.get_row function.
FOR i IN 1 .. fp_mslov.rowcount
LOOP
   returned_rec := fp_mslov.get_row(i);
END LOOP;
Now, you can do what you want with returned row.
RETURNED_REC record has the following fields which correspond to parameters of
the
fp_mslov.show_lov function: id, col1, col2, col3, col4, col5
You know that in id field will be empno column, in col1 -> sal, etc
So, you can process them:
FOR i IN 1 .. fp_mslov.rowcount
LOOP
   returned_rec := fp_mslov.get_row(i);
   message('Empno: ' || returned_rec.id);
   message('Sal: ' || returned_rec.col1);
   message('Comm: ' || returned_rec.col2);
   message('Sal+Comm: ' || returned_rec.col3);
END LOOP;
Remember that returned values always are varchar2 values.
So if you need, for example, a date you need explicitly convert it to char when
invoking
fp_mslov.show_lov and then (after fp_mslov.get_row) convert it to date with the
same format mask.
For example:
   IF fp_mslov.show_lov (
      col4_in => 'TO_CHAR(hiredate, ''DD.MM.YYYY HH24:MI:SS'')',
   ... TO_DATE(returned_rec.col4, 'DD.MM.YYYY HH24:MI:SS');
To clear memory structures which used by global record group and others
variables,
you need to use fp_mslov.clear procedure.
And now all together:
DECLARE
   returned_rec  FP_MSLOV.OUT_RECORD_TYPE;
BEGIN
   IF fp_mslov.show_lov (
      label_in => 'first_name || '' '' || last_name',
      id_in => 'empno',
      col1_in => 'sal',
      col2_in => 'comm'
      col3_in => 'sal + NVL(comm, 0)',
      from_clause_in => 'FROM emp ORDER BY sal DESC',
      title_in => 'Select employees'
   THEN
      FOR i IN 1 .. fp_mslov.rowcount
      LOOP
         returned_rec := fp_mslov.get_row(i);
         message('Empno: ' || returned_rec.id);
         message('Sal: ' || returned_rec.col1);
         message('Comm: ' || returned_rec.col2);
         message('Sal+Comm: ' || returned_rec.col3);
      END LOOP;
   ELSE
      NULL; -- User press Cancel
   END IF;
   fp_mslov.clear;
END;