Extending Devise::Mailer to accept attributes available to the view

devise_mailer_with_attributes.rb

module DeviseMailerWithAttributes
  class Devise::Mailer < ::ActionMailer::Base

    alias_method :old_confirmation_instructions, :confirmation_instructions
    alias_method :old_reset_password_instructions, :reset_password_instructions
    alias_method :old_unlock_instructions, :unlock_instructions
    alias_method :old_invitation_instructions, :invitation_instructions

    def confirmation_instructions(record, attributes={})
      set_attributes(attributes)
      old_confirmation_instructions(record)
    end

    def reset_password_instructions(record, attributes={})
      set_attributes(attributes)
      old_reset_password_instructions(record)
    end

    def unlock_instructions(record, attributes={})
      set_attributes(attributes)
      old_unlock_instructions(record)
    end

    def invitation_instructions(record, attributes={})
      set_attributes(attributes)
      old_invitation_instructions(record)
    end

    def set_attributes(attributes)
      attributes.each {|k,v| instance_variable_set("@#{k}", v) }
    end
  end
  
  class User
    alias_method :old_send_confirmation_instructions, :send_confirmation_instructions
    alias_method :old_send_reset_password_instructions, :send_reset_password_instructions
    alias_method :old_send_unlock_instructions, :send_unlock_instructions
    alias_method :old_invite!, :invite!
    
    def send_reset_password_instructions(attributes={})
      generate_reset_password_token!
      ::Devise.mailer.reset_password_instructions(self, attributes).deliver
    end
    
    def send_confirmation_instructions(attributes={})
      generate_confirmation_token! if self.confirmation_token.nil?
      ::Devise.mailer.confirmation_instructions(self, attributes).deliver
    end
    
    def send_unlock_instructions(attributes={})
      ::Devise.mailer.unlock_instructions(self, attributes).deliver
    end
    
    def invite!(attributes={})
      if new_record? || invited?
        self.skip_confirmation! if self.new_record? && self.respond_to?(:skip_confirmation!)
        generate_invitation_token if self.invitation_token.nil?
        self.invitation_sent_at = Time.now.utc
        save(:validate => false)
        ::Devise.mailer.invitation_instructions(self, attributes).deliver
      end
    end
  end
end