Rails条件验证抛出未定义的模型方法

Question

So, I've been working on an app (Rails 5) and I wanted to verify if the attribute (server) chosen by the user is in the scope I want.

class Player < ApplicationRecord
  validates :nick, presence: true, length: { maximum: 20 }
  validates :description, length: { maximum: 275 }
  validates :server, presence: true, if: server_exists?

  def server_exists?
    server == "NA"
  end

end

When I try to access localhos:3000 I get the following error:

undefined method `server_exists?' for Player (call 'Player.connection' to establish a connection):Class

Does anybody know how to fix it?

Thanks!

Answer 1

You can associate the :if and :unless options with a symbol corresponding to the name of a method that will get called right before validation happens.

Try with :server_exists? instead server_exists? :

validates :server, presence: true, if: :server_exists?

Answer 2

You need to use a symbol for the method name:

http://guides.rubyonrails.org/active_record_validations.html#using-a-symbol-with-if-and-unless

validates :server, presence: true, if: :server_exists?