Using FriendlyId inside a module

Question

I'm using FriendlyId across many of my models. I noticed some redundancy in my code as far as creating functionality for updating urls so I decided to put it in a module:

module TestModule
  def should_generate_new_friendly_id?
    name_changed?
  end
end

The problem now is if I take the essential line of code needed to create the slugs out of my classes and into my module

extend FriendlyId; friendly_id :name, use: :slugged

I get this error:

undefined method `relation' for class `Module'

Is there any way to get this to work without me having to right the extend declaration for every one of my models?

Answer 1

You can let your module extend the friendly for the classes you include it in.

module TestModule
  def self.included(klass)
    klass.extend FriendlyId
    klass.class_eval do
      friendly_id :name, use: :slugged
    end
    include InstanceMethods
  end
  module InstanceMethods
    def should_generate_new_friendly_id?
      name_changed?
    end
  end
end

Then in your model you'll just include this

class MyModel < ActiveRecord::Base
  include TestModule
  # the rest of the class
end

Also you could do it without the extra module

module TestModule
  def self.included(klass)
    klass.extend FriendlyId
    klass.class_eval do
      friendly_id :name, use: :slugged
      def should_generate_new_friendly_id?
        name_changed?
      end
    end
  end
end