包含范围如何在其他模块包含的模块中写入类？（轨道 4.2）答案

【问题标题】：How include scopes write in module included by other module to a class? (rails 4.2)包含范围如何在其他模块包含的模块中写入类？（轨道 4.2）
【发布时间】：2017-01-21 05:41:45
【问题描述】：

我有一个类似的模块

module FooConcern
  extend ActiveSupport::Concern

  def self.included(klass)
    klass.instance_eval do
      scope :deleted, -> { where(state: STATE_DELETED) }
      scope :closed, -> { where(state: STATE_CLOSED) }
      scope :opened, -> { where(state: STATE_OPENED) }
    end
  end


  included do
    def deleted?
      state == STATE_DELETED
    end


    def closed?
      state == STATE_CLOSED
    end


    def opened?
      state == STATE_OPENED
    end
  end
end

和其他模块，如：

module Bar
  include FooConcern
  include LotConcern
  include OfConcern
  include OtherConcern
  include ModuleConcern
end

和使用 Bar 的类：

class Baz
  include Bar
end

错误：wrong number of arguments (given 0, expected 1) module Bar include Foo 在被包含在类之前，所以我认为它不能给出参数。

如果我将范围直接放在块 included do 中，则会引发错误：undefined method 'scope' for Bar:Module

如何按模块本身包含我的范围？

【问题讨论】：

标签： ruby-on-rails module scope include ruby-on-rails-4.2

【解决方案1】：

我找到了这个方法，如果你有更好的...

def self.included(klass)
  klass.instance_eval do
    include FooConcern
  end
end

在条形模块中

【讨论】：