Problem with validates_presence_of :on=> :update


I’m having what’s probably a stupid-newbie problem with
validates_presence_of and I’m hoping someone will point me in the right

Bottom line is that validates_presence_of does not seem to be ‘firing’
when I use the :on => :update option. If I don’t include the option,
the validation does fire.

The problem is that I want to save the record before I present it to the
user to update. When it comes back from the user I want to make sure
they’ve updated a couple of fields and so that’s where I need to do the

When I leave off the option, the validation is firing on the initial
save. That’s ‘bad’ because the data is not supposed to be there at
that point. When I include the :on => :update, it doesn’t fire on the
initial save. That’s ‘good.’ But if I leave the fields that I’m
validating-on empty when I submit the form, the @actor.update happens
without throwing an error. The record is definitely getting updated in
the database. That’s very ‘bad.’

Anybody have any ideas?