活动记录的简单Railtie扩展

Question

我正在创建一个Rails 3.0.3 gem，但无法让它工作：

# attached.rb
module Attached
  require 'attached/railtie' if defined?(Rails)
  def self.include(base)
    base.send :extend, ClassMethods
  end
  module ClassMethods
    def acts_as_fail
    end
  end
end

# attached/railtie.rb
require 'attached'
require 'rails'

module Attached
  class Railtie < Rails::Railtie
    initializer 'attached.initialize' do
      ActiveSupport.on_load(:active_record) do
        ActiveRecord::Base.send :include, Attached
      end
    end
  end
end

当我将acts_as_fail添加到我的任何ActiveRecord模型中时，我都会得到undefined local variable or method 'acts_as_fail'。请帮帮我！我对这些看似微不足道的代码感到非常沮丧！谢谢!

Answer 1

当正确的方法是self.included时，您正在定义self.include (第4行)。

Answer 2

您可以通过直接使用extend来简化代码：

# attached.rb
module Attached
  require 'attached/railtie' if defined?(Rails)
  def acts_as_fail
  end
end

# attached/railtie.rb
require 'attached'
require 'rails'

module Attached
  class Railtie < Rails::Railtie
    initializer 'attached.initialize' do
      ActiveSupport.on_load(:active_record) do
        ActiveRecord::Base.send :extend, Attached
      end
    end
  end
end

这是一个很好的读物：http://yehudakatz.com/2009/11/12/better-ruby-idioms/