Rails 3 - how to skip validation rule?

Question

I have for the registration form this validation rule:

  validates :email, 
    :presence => {:message => 'cannot be blank.'}, 
    :allow_blank => true, 
    :format => {
      :with => /\A[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]+\z/, 
      :message => 'address is not valid. Please, fix it.'
    }, 
    :uniqueness => true

This rule check, if a user fill into the registration form email address (+ its correct format).

Now I am trying to add the opportunity to log in with using Twitter. Twitter doesn't provide user's email address.

How to skip in this case the validation rule above?

Answer 1

You can skip validation while saving the user in your code. Instead of using user.save!, use user.save(:validate => false). Learnt this trick from Railscasts episode on Omniauth

Answer 2

I'm not sure whether my answer is correct, just trying to help.

I think you can take help from this question. If i modify the accepted answer for your question, it will be like (DISCLAIMER: I could not test the following codes as env is not ready in the computer i'm working now)

validates :email, 
  :presence => {:message => 'cannot be blank.', :if => :email_required? },
  :allow_blank => true, 
  :format => {
    :with => /\A[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]+\z/, 
    :message => 'address is not valid. Please, fix it.'
  },
  :uniqueness => true

def email_required?
  #logic here
end

Now, you update the email_required? method to determine whether it is from twitter or not! If from twitter, return false otherwise true.

I believe, you need use same :if for the :uniqueness validator too. otherwise it will. Though, i'm not sure too :(. Sorry