Validation: Two items cannot be null or filled at the same time

Question

Hello forum members,
I have a question about item level validation and was hoping someone would be able to shed some light on my problem.
I'll go into a quick background of what the app does first so you will have an idea of what I'm trying to get at (or if you can suggest a better approach).
Our team, on a regular basis, receives records that require analyzing. Over the years, we've compiled a pretty good list of possible analyses for any record. We used to do this by manually going into sql developer and changing the analysis in the analysis field, but that posed problems of spelling mistakes and other human errors.
I've created a front end application that will scrape all possible analyses from the table into a drop down menu thus limiting the amount of human input as possible. The problem here is that as things grow, there will always be a new problem that does not fit the analysis we have used in the past. So I would like to give the ability for the team to use a text field to enter a new analysis for those cases (and then subsequent records can find it in the drop down menu).
The two application items used in this problem is: p_select_list and p_text_field.
In my first iteration of this application, I added an extra value in p_select_list called "Other". Some nifty javascript would check to make sure that if anything but "Other" was selected, p_text_field would be disabled (there was a problem with that where on page load, the field would be enabled even though "Other" wasn't selected).
We've been having some javascript issues while migrating our application from development to testing to production, so I would like to avoid javascript unless there really is no other option.
What I'm trying to implement now is a page level validation on both p_select_list and p_text_field to test to make sure that either p_select_list is not null or p_text_field is not null.
I know there are 3 cases to test for (both null, both not null and only one is null), so I used a function returning boolean validation.
I started off small and just had the following:
if ((p_select_list is not null) and (p_text_field is not null)) then
return true;
else
return false;
end if;
I then chose something in the select list and entered some garbage in the text field and hit submit. The validation worked like a charm!
Now I added the both null check:
if ((p_select_list is not null) and (p_text_field is not null)) then
return true;
elsif ((p_select_list is null) and (p_text_field is null)) then
return true;
else
return false;
end if;
However, I go into a record and enter something into the select list and leave the text field blank, and it throws the error at me. Then I tried both items as null and that breaks too. However, I can't say that this is the work of the script since it failed the one case it wasn't supposed to.
Do you know what I'm doing wrong here? Is there some way for APEX to ensure that only one of the two fields has a non-null value?
Thank you in advance,
Ivan
Edited by: ichin on Jan 28, 2009 3:40 PM

Answer 1

Hi Ichin,
I am a bit confused with your statement -
if ((p_select_list is not null) and (p_text_field is not null)) then
return true;
elsif ((p_select_list is null) and (p_text_field is null)) then
return true;
else
return false;
end if;Here this statement -
if ((p_select_list is not null) and (p_text_field is not null)) then
return true;returning the result TRUE when both fields are not null
And this statement -
elsif ((p_select_list is null) and (p_text_field is null)) then
return true;returning the result TRUE again when both fields are null. If you see closely basically is not validating becoz it returning true whatever the input is.
I do not know what you want to use the second statement when you have else statement at the end. It will return false if one or both fields are null unless you want to validate either text field.
Hope this make sense.
Regards,
M Tajuddin
web: http://tajuddin.whitpeagesbd.com