Rails Error Messages

Question

I encountered an issue today I haven't seen before - I have a custom validation to check if a discount code has already been used in my Order model:

validate :valid_discount_code

def valid_discount_code
  is_valid = false
  code = nil

  if discount_code.present?

    if discount_code.try(:downcase) == 'xyz'
      code = 'xyz'
      is_valid = true
    else
      code = Coupon.find_by_coupon_code(discount_code)
      is_valid = code.present?
    end

    if code.nil?
      is_valid = false
      errors.add(:discount_code, "is not a valid referral code")
    elsif ( code.present? && Coupon.where(email: email, coupon_code: code).present? )
      is_valid = false
      errors.add(:discount_code, "has already been used.")
    end


    puts "------------"
    puts errors.full_messages   ## successfully 'puts' the correct error message into my console.
    puts "------------"

    if is_valid
     .... do stuff.....
    end

  end

end

In my controller:

   if current_order.update_attributes(discount_code: params[:coupon_code].downcase, another_attribute: other_stuff)

      ....
      session[:order_id] = nil
      render json: { charged: 'true' }.as_json

    else

      puts "==============="
      puts current_order.id     # shows the correct current order ID
      puts current_order.errors.full_messages    # shows that there are no errors present
      puts "==============="

      render json: { charged: 'false', errors: current_order.errors.full_messages }.as_json

    end

So it looks like at update_attributes, it runs the validation, fails the validation, creates the error message, and then once it's back at my controller the error message is gone. I'm stumped as to what can be causing that issue.

EDIT:

Here is what current_order is:

In ApplicationController.rb:

def current_order
  session[:order_id].present? ? Order.find(session[:order_id]) : Order.new
end

Answer 1

Looks like every time you call current_order it reruns the find method. You can confirm this in the logs, but try not to call that, or at least memoize it. In an instance variable, the same order will be used everytime.

def current_order
  @current_order ||= (Order.find_by_id(session[:order_id]) || Order.new)
end