Is it possible to change LOV definition using dynamic action?

Question

Hi,
I have a multi-select LOV page item, P27_MULTI_CLASS_CODE, defined as below.  On page load, this list only contains values based on what has been passed to P27_OLO_CODE or P27_OLO_CODE_SW.
SELECT DISTINCT c.class_code d, c.class_code r
  FROM ORGANIZATION o,
       POSITION p,
       CLASS c
WHERE o.org_wk = p.org_wk
   AND p.class_wk = c.class_wk
   AND o.org_active_flag = 'Y'
   AND p.pos_active_flag = 'Y'
   AND c.class_active_flag = 'Y'
   AND (o.olo_code = :P27_OLO_CODE
        OR o.olo_code = :P27_OLO_CODE_SW)
ORDER BY c.class_code ASC
Before submitting the page, I would like the LOV definition of P27_MULTI_CLASS_CODE to change to the following (similar query without reference to P27_OLO_CODE or P27_OLO_CODE_SW) based on whether the user selects checkbox item, P27_ALLOW_SW.   By doing this, P27_MULTI_CLASS_CODE would contain a full range of values rather than limited values.
SELECT DISTINCT c.class_code d, c.class_code r
  FROM ORGANIZATION o,
       POSITION p,
       CLASS c
WHERE o.org_wk = p.org_wk
   AND p.class_wk = c.class_wk
   AND o.org_active_flag = 'Y'
   AND p.pos_active_flag = 'Y'
   AND c.class_active_flag = 'Y'
ORDER BY c.class_code ASC
I wanted to avoid writing Javascript.  Is this possible using dynamic actions...or at least somehow refresh P27_MULTI_CLASS_CODE so that it ignores P27_OLO_CODE and P27_OLO_CODE_SW?
I've tried creating a dynamic action to clear the value of  P27_OLO_CODE or P27_OLO_CODE_SW, in hope it would trigger P27_MULTI_CLASS_CODE to display all values, but it has not been successful.  Any ideas?
APEX 4.2

Answer 1

I was able to resolve by changing the SQL statement to P27_MULTI_CLASS_CODE.  Note:  I also included an additional condition.
SELECT DISTINCT c.class_code d, c.class_code r
  FROM ORGANIZATION o,
       POSITION p,
       CLASS c
WHERE o.org_wk = p.org_wk
   AND p.class_wk = c.class_wk
   AND o.org_active_flag = 'Y'
   AND p.pos_active_flag = 'Y'
   AND c.class_active_flag = 'Y'
   AND (:P27_ALLOW_SW = 'Y'
        OR (o.olo_code =  :P27_OLO_CODE
            OR o.olo_code = :P27_OLO_CODE_SW)
   AND (:P27_PAY_PLAN IS NULL
         OR p.pay_plan = :P27_PAY_PLAN)
ORDER BY c.class_code ASC
I also changed the Cascading LOV Parent Item(s) value to:  P27_OLO_CODE,P27_OLO_CODE_SW,P27_PAY_PLAN,P27_ALLOW_SW.  Optimize Refresh = No, since a change in any one of these values should trigger refresh of LOV.
The Dynamic Action was also modified to NULL out P27_OLO_CODE,P27_OLO_CODE_SW when P27_ALLOW_SW was enabled.
So far, so good!  Thanks for your suggestions Tom and Howard!