Including a module in a Rails 5 Application Record class

Question

I am using Application Record to simplify shared logic throughout an application.

Here's an example that writes a scope for a boolean and its inverse. This works well:

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true

  def self.boolean_scope(attr, opposite = nil)
    scope(attr, -> { where("#{attr}": true) })
    scope(opposite, -> { where("#{attr}": false) }) if opposite.present?
  end
end

class User < ApplicationRecord
  boolean_scope :verified, :unverified
end

class Message < ApplicationRecord
  boolean_scope :sent, :pending
end

My Application Record class got long enough it made sense for me to break it up into individual modules and load those as needed.

Here's my attempted solution:

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true
  include ScopeHelpers
end

module ScopeHelpers
  def self.boolean_scope(attr, opposite = nil)
    scope(attr, -> { where("#{attr}": true) })
    scope(opposite, -> { where("#{attr}": false) }) if opposite.present?
  end
end

class User < ApplicationRecord
  boolean_scope :verified, :unverified
end

class Message < ApplicationRecord
  boolean_scope :sent, :pending
end

In this case, I don't get a load error, but boolean_scope is then undefined on User and Message.

Is there a way to ensure the included modules are loaded at the appropriate time and available to Application Record and its inheriting models?

---

I've also attempted to have the models include the modules directly and that did not fix the issue.

module ScopeHelpers
  def self.boolean_scope(attr, opposite = nil)
    scope(attr, -> { where("#{attr}": true) })
    scope(opposite, -> { where("#{attr}": false) }) if opposite.present?
  end
end

class User < ApplicationRecord
  include ScopeHelpers
  boolean_scope :verified, :unverified
end

class Message < ApplicationRecord
  include ScopeHelpers
  boolean_scope :sent, :pending
end

Answer 1

作为@Pavan答案的替代方法，您可以执行以下操作：

module ScopeHelpers
  extend ActiveSupport::Concern # to handle ClassMethods submodule

  module ClassMethods
    def boolean_scope(attr, opposite = nil)
      scope(attr, -> { where(attr => true) })
      scope(opposite, -> { where(attr => false) }) if opposite.present?
    end
  end
end

# then use it as usual
class ApplicationRecord < ActiveRecord::Base
  include ScopeHelpers
  ...
end