allow_nil not working?

[nozpheratu]

I might be misunderstanding it's usage, but given the following code:

 validates :state, :existence => { :allow_nil => true}

Should the parent existence only be checked if a value is provided? In other words, if it's nil no validation should take place correct?

For some reason when I add the allow_nil option block it does indeed allow nil, but it also allows me to enter any erroneous value without any existence validations kicking in.

[alotela]

seems it doesn't work also when I use both and allow_nil at the same time

[AviDuda]

+1

[ghost]

+1

[jmccaffrey]

I came across this from an issue on SO
http://stackoverflow.com/questions/15884024/ror-validates-existence-of-with-nil-foreign-key-not-working/15886258#15886258

I cloned the project, wrote a simple test to verify that it wouldn't save if the value was bogus, and verified that as soon as you add allow_nil => true, it will always save....NO MATTER WHAT. I debugged a bit and verified that the code is not even called at all if you set allow_nil => true. I'm not sure why that is, probably something with how the validators are registered and called in a higher-level spot, but there is a work around that I was able to use.

If I used this, my test would behave properly (invoke the logic if the value was not nil, skip it otherwise), and the record would not save if there is a non-nil, but not valid value:

validates_existence_of :name, :unless => Proc.new { |user| user.name_id.blank? }

[sankaranarayanan]

use validates :state, :existence => true, :allow_nil => true
check this line https://github.com/perfectline/validates_existence/blob/master/test/rails31/models/user_with_allow_nil.rb#L7