Shrine: backgrounding documentation update - location of plugin: backgrounding

[rosskevin]

This one is a bit mystifying. I removed my namespaces from the job to take it out of the equation, but still see the same error. Is the structure of shrine compatible with namespaced usage? What am I missing here?

Error

NoMethodError:
  undefined method `promote' for Shrine::Attacher:Class
# ./app/jobs/shrine_promote_job.rb:6:in `perform'
# /Users/kross/.rvm/gems/ruby-2.4.1@af/gems/sidekiq-5.0.5/lib/sidekiq/testing.rb:301:in `execute_job'

Uploaders

module Af
  module Uploader
    class PdfUploader < ::Shrine
      plugin :determine_mime_type
      plugin :validation_helpers

      Attacher.validate do
        validate_extension_inclusion %w(pdf)
        validate_max_size 15.megabytes, message: 'is too large (max is 15 MB)'
        validate_mime_type_inclusion ['application/pdf']
      end
    end
  end
end

module Af
  module Uploader
    class BackgroundPdfUploader < PdfUploader
      plugin :backgrounding
      Attacher.promote { |data| ShrinePromoteJob.perform_async(data) }
      Attacher.delete { |data| ShrineDeleteJob.perform_async(data) }
    end
  end
end

Job

class ShrinePromoteJob
  include ::Sidekiq::Worker
  def perform(data)
    Shrine::Attacher.promote(data)
  end
end

Usage

module Af
  module Commerce
    class Agreement < ActiveRecord::Base
      if Af.dev?
        # in dev, do everything in the foreground to ease seeding
        include Af::Uploader::PdfUploader::Attachment.new(:document)
      else
        # in every other environment, background the work
        include Af::Uploader::BackgroundPdfUploader::Attachment.new(:document)
      end
    end
  end
end

[rosskevin]

Note, the same results occur with explicit root Shrine namespace usage from the job:

  class ShrinePromoteJob
    include ::Sidekiq::Worker
    def perform(data)
      ::Shrine::Attacher.promote(data)
    end
  end

[rosskevin]

I also tried collapsing the BackgroudPdfUploader so it had no other hierarchy:

module Af
  module Uploader
    class BackgroundPdfUploader < ::Shrine
      plugin :determine_mime_type
      plugin :validation_helpers
      Attacher.validate do
        validate_extension_inclusion %w(pdf)
        validate_max_size 15.megabytes, message: 'is too large (max is 15 MB)'
        validate_mime_type_inclusion ['application/pdf']
      end

      plugin :backgrounding

      Attacher.promote { |data| ShrinePromoteJob.perform_async(data) }
      Attacher.delete { |data| ShrineDeleteJob.perform_async(data) }
    end
  end
end

Same error.

[rosskevin]

If I move the backgrounding setup to the initializer, it all works, so it appears it has be turned on or off for the entire system.

[rosskevin]

Figured it out.

The plugin provides Attacher.promote and Attacher.delete methods, which allow you to hook up to promoting and deleting and spawn background jobs, by passing a block.

Shrine.plugin :backgrounding
Shrine::Attacher.promote { |data| PromoteJob.perform_async(data) }
Shrine::Attacher.delete { |data| DeleteJob.perform_async(data) }
If you don't want to apply backgrounding for all uploaders, you can declare the hooks only for specific uploaders.

class MyUploader < Shrine
Attacher.promote { |data| PromoteJob.perform_async(data) }
Attacher.delete { |data| DeleteJob.perform_async(data) }
end

It might be worth noting in this section, that the Shrine.plugin :backgrounding must be done in the initializer, even though you select the specific uploaders to do the:

  Attacher.promote { |data| PromoteJob.perform_async(data) }
  Attacher.delete { |data| DeleteJob.perform_async(data) }

The current doc is technically correct, but this is a bit of a gotcha/hard to spot.

[janko]

Glad that you figured it out by yourself. Ok, I'll see how I can make the backgrounding documentation a bit clearer.