Rails update_attributes without save?

Question

Is there an alternative to update_attributes that does not save the record?

So I could do something like:

@car = Car.new(:make => 'GMC')
#other processing
@car.update_attributes(:model => 'Sierra', :year => "2012", :looks => "Super Sexy, wanna make love to it")
#other processing
@car.save

BTW, I know I can @car.model = 'Sierra', but I want to update them all on one line.

Answer 1

I believe what you are looking for is assign_attributes.

It's basically the same as update_attributes but it doesn't save the record:

class User < ActiveRecord::Base
  attr_accessible :name
  attr_accessible :name, :is_admin, :as => :admin
end

user = User.new
user.assign_attributes({ :name => 'Josh', :is_admin => true }) # Raises an ActiveModel::MassAssignmentSecurity::Error
user.assign_attributes({ :name => 'Bob'})
user.name        # => "Bob"
user.is_admin?   # => false
user.new_record? # => true