I need to conditionally set the
#required property of a specific form field to FALSE. I know already that the requirement check is performed in
_form_validate(). However this function is executed BEFORE any other custom attached validation handlers as it is in fact responsible for calling them.
So I'd like to know if there's a way to alter
_form_validate() is called...?
Or maybe there are ways to perform the requirement check at a later time in validation?
PS: One could also do reverse thinking (make the field optional and require it in a custom validation handler), but there are reasons I cannot do this.