validate and update single attribute rails

Question

I have the following in my user model

attr_accessible :avatar, :email

validates_presence_of :email
has_attached_file :avatar # paperclip

validates_attachment_s         


        

Answer 1

Here is my solution. It keeps the same behaviour than .valid? method, witch returns true or false, and add errors on the model on witch it was called.

class MyModel < ActiveRecord::Base
  def valid_attributes?(attributes)
    mock = self.class.new(self.attributes)
    mock.valid?
    mock.errors.to_hash.select { |attribute| attributes.include? attribute }.each do |error_key, error_messages|
      error_messages.each do |error_message|
        self.errors.add(error_key, error_message)
      end
    end

    self.errors.to_hash.empty?
  end
end

> my_model.valid_attributes? [:first_name, :email] # => returns true if first_name and email is valid, returns false if at least one is not valid
> my_modal.errors.messages # => now contain errors of the previous validation
{'first_name' => ["can't be blank"]}