Rails模型的动态关注点

Question

For a project I needed the ability to upload video's to a video server. At first the scope was to only upload to a Kaltura video server. To enable this, I created a simple concern that added some callback methods to the model which handle the uploads.

These callback methods (specifically for Kaltura) are being loaded like so:

class Videofile < ActiveRecord::Base
  include KalturaBox::Entry
end

And they contain basics like this (simplified version):

module KalturaBox
  module Entry


    extend ActiveSupport::Concern

      included do

        before_save :create_kaltura_item, on: :create

        private
          def create_kaltura_item
            puts 'create callback called'
            self.upload
          end
      end
end

Now the scope has broadened, and I was asked to also include Vimeo uploads as an option.

Is it possible to dynamically embed the concerns based on an attribute of the model, or should I consider using STI instead?

I was thinking about creating a drop-down called "video_type". How do I include the correct code based on that attribute?

Answer 1

I was thinking about creating a drop-down called "video_type". How do I include the correct code based on that attribute?

Use conditional callbacks .

before_save :create_kaltura_item, on: :create, if: :kaltura?

def kaltura?
  video_type == 'kaltura'
end

This way you can include both concerns statically.