Re: post-change and on-validate-field trigger

In article <1995Jun15.111247.26439_at_newton.ccs.tuns.ca>, <James Richard> wrote:
>In article <3ri50q$70a_at_artecon.artecon.com> quach_at_ext423.artecon.com (Phuong Quach) writes:
>>Hi all,
>> I'm still confusing on POST-CHANGE and ON-VALIDATE-FIELD.
>>Please help. When is the best time to create either one for the
>>field trigger?
>>
>>Phuong
>>Thank you.
>
>I'm not sure why ORACLE added the ON-VALIDATE-FIELD (and others)
>trigger. My guess is for logistics reasons. So I complied.
>
>I use ON-VALIDATE-FIELD for checking the validity of the current field,
>and use POST-CHANGE to affect any changes to other fields.
>
>James Richard (JRICHARD_at_TUNS.CA)
>"No Assembler Required!"

My understanding of this (I heard this from one of our senior developers) was that the POST-CHANGE trigger was a hold-over from SQL*Forms 2.3 (not sure if this is actually true or not). I use ON-VALIDATE-FIELD for field validation, and do not use POST-CHANGE at all. If you put a form that uses both triggers in debug mode, I think you will find that the POST-CHANGE trigger fires BEFORE the ON-VALIDATE-FIELD trigger (at least this is my observation). This can make for validation loops if you are populating other fields via a POST-CHANGE trigger using a field that you are also validating (via ON-VALIDATE-FIELD trigger). Some of our early SQL*Forms 3.0 forms had validation loop problems from these two triggers, and the best solution was to remove the POST-CHANGE triggers from the forms. I usually "think twice" before considering the use of a POST-CHANGE trigger on a form field.

Just some thoughts. Your mileage may vary.

Paul

-- 
Paul Mickel				  Internet: mickel_at_oes.orst.edu
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