This Rails gem lets you easily declare which attribute validations to skip in you models, and choose when to skip them in your controllers.

Add this line to your application's Gemfile:

gem 'validation_skipper'

And then execute:

$ bundle

Or install it yourself as:

$ gem install validation_skipper

Let's say you have a User model with a name, phone, and password.

validates :name, :presence => true
validates :phone, :presence => true
validates :password, :presence => true

can_skip_validation_for :name, :phone, :password

(Note: this does not automatically skip them, but makes them eligible for skipping)

validates :name, :presence => true, :unless => skip_name_validation?
validates :phone, :presence => true, :unless => skip_phone_validation?
validates :password, :presence => true, :unless => skip_pasword_validation?

Now just pass the names of the fields you want to skip validation for from within your controller, ex:

def create
  @user = User.new(params[:user])
  @user.skip_validation_for :name, :phone
  # The rest of your code goes here...
end

This will now skip the validations for name and phone only, but still validate for password.

And there you go, anytime you want the same effect elsewhere, just follow this approach.

Enjoy!

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request