ruby-on-rails - ruby rails : Calling class method from concern

Question

在 Rails 中，是否可以在关注点本身中调用包含关注点的类的方法？即:

class Foo < ApplicationRecord
  include Encryptable

  def self.encrypted_attributes
     %i[attr_1 attr_2]
  end
end

module Encryptable
  extend ActiveSupport::Concern

  included do
    self.encrypted_attributes do |attr|
      define_method("#{attr}=") do |arg|
        # do some stuff
      end

      define_method("#{attr}") do
        # do some stuff
      end
    end
  end
end

问题是，当我尝试这样做时，出现如下错误:

*** NoMethodError Exception: undefined method 'encrypted_attributes' for #<Class:0x00005648d71c2430>

而且，在关注点内部调试时，我得到这样的结果:

(byebug) self
Foo (call 'Foo' to establish a connection)
(byebug) self.class
Class

Answer 1

Ruby 是一种脚本语言，顺序很重要。可以执行以下操作:

class Foo < ApplicationRecord
  def self.encrypted_attributes
     %i[attr_1 attr_2]
  end

  # OK, now we have self.encrypted_attributes defined
  include Encryptable
end

更多信息:ActiveSupport::Concern#included .