Rails Conditional Validation

Question

So I have two models here:

class Screen < ActiveRecord::Base
  belongs_to :user
  validates :screen_size, :numericality =>{:less_than_or_equal_to =>         


        

Answer 1

change:

:if => "user.access==1"

with:

:if => lambda { |screen| screen.user.try(:access) ==1 }

Because:

• you need to pass a function to evaluate condition on the fly

• if your screen doesn't have any user, a mere screen.user.access would throw an exception