Question

I want to DRY up several models by moving shared scopes into a module, something like:

module CommonScopes
  extend ActiveSupport::Concern

  module ClassMethods
    scope :ordered_for_display, order("#{self.to_s.tableize}.rank asc")
  end
end

I also want to create shared specs that test the module. Unfortunately when I try to include the shared scope in my model I get:

undefined method `order' for CommonScopes::ClassMethods:Module

Any ideas? Thanks!

Answer 1

You can use instance_eval

module CommonScopes
  extend ActiveSupport::Concern

  def self.included(klass)
    klass.instance_eval do
      scope :ordered_for_display, order("#{self.to_s.tableize}.rank asc")
    end
  end
end