About custom validations

Hello,

I suppose this topic has been widely discussed, but i've not found exactly what i need.

I thought validate_associations would in fact validate the associations of my models, but it simply verifies that the fields of the object are valid. So i need to create some custom validations to do

I found one solution:

[code] validate :obj_must_exist

def obj_must_exist   errors.add(:obj_id, "must point to an existing obj") if obj_id && obj.nil? end [/code]

But now i need it in a helper or something like that, because i've to reuse the same validation several times. I created a file in config/initializers called validations.rb and put this:

ActiveRecord::Base.class_eval do   def self.validates_object_exists(obj, obj_id)     obj.errors.add(obj_id, "must point to an existing #{obj}") if obj_id

obj.nil?

  end end

But it's just not working... So, what's the "rails way" to do that?

Thank you.

What is "just not working"? What is exactly the given error? Are you sure the file is getting loaded? Have you tried explicitly loading it?