在关注中定义的覆盖范围内调用 super

问题描述

我希望将附加查询链接到模型中的范围.范围在关注中定义.

I'm looking to chain an additional query onto a scope in a model. The scope is defined in a concern.

module Companyable
    extend ActiveSupport::Concern

    included do
        scope :for_company, ->(id) {
            where(:company_id => id)
        }
    end
end


class Order < ActiveRecord::Base
    include Companyable

    # I'd like to be able to do something like this:
    scope :for_company, ->(id) {
        super(id).where.not(:status => 'cancelled')
    }
end

然而，这可以理解地抛出一个 NameError: undefined method 'for_company' for class 'Order'

However, that understandably throws a NameError: undefined method 'for_company' for class 'Order'

推荐答案

这是我想出的解决方案:

Here's the solution I came up with in my case:

而不是 scope，只需使用常规类方法，因为 scope 只是类方法的语法糖".当您需要使用 super 进行覆盖时，这更容易处理.在您的情况下，它看起来像这样:

Rather than scope, just go with a regular class method since scope is just "syntactic sugar" for a class method. This is easier to deal with when you need to override using super. In your case it would look like this:

module Companyable
  extend ActiveSupport::Concern

  module ClassMethods
    def for_company(id)
      where(:company_id => id)
    end
  end
end



class Order < ActiveRecord::Base
  include Companyable

  def self.for_company(id)
    super(id).where.not(:status => 'cancelled')
  end
end

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