Question

I’m using ActiveAdmin and if I edit an entry and leave a TEXT field blank, in the db it gets set as empty string — when it really should be getting set as NULL (and NULL is allowed on the schema for those fields).

Has anyone else encountered this issue and solved it?

Answer 1

(Moved from comments, as I found more and more to say about it):

I haven’t used ActiveAdmin, but… Any reason why an empty string wouldn’t be stored as an empty string but a NULL?

I think the empty-string-to-Nil conversion should never be automatic, since it violates least surprise. I’d appreciate a doc reference stating the opposite if I’m wrong…

As for solving it, I’d guess this might do the trick:

before_validation do
  self.mytextfield = nil if self.mytextfield && self.mytextfield.empty?
end

Or, more systemic, this gem.

class MyModel < ActiveRecord::Base
  nilify_blanks :only => [:mytextfield]
end