Shrine is a toolkit for handling file attachments in Ruby applications. Some highlights:

• Modular design – the plugin system allows you to load only the functionality you need
• Memory friendly – streaming uploads and downloads make it work great with large files
• Cloud storage – store files on disk, AWS S3, Google Cloud, Cloudinary and others
• Persistence integrations – works with Sequel, ActiveRecord, ROM, Hanami and Mongoid and others
• Flexible processing – generate thumbnails eagerly or on-the-fly using ImageMagick or libvips
• Metadata validation – validate files based on extracted metadata
• Direct uploads – upload asynchronously to your app or to the cloud using Uppy
• Resumable uploads – make large file uploads resumable on S3 or tus
• Background jobs – built-in support for background processing that supports any backgrounding library

If you're curious how it compares to other file attachment libraries, see the Advantages of Shrine. Otherwise, follow along with the Getting Started guide.

Run:

bundle add shrine

Then add config/initializers/shrine.rb which sets up the storage and loads ORM integration:

require "shrine"
require "shrine/storage/file_system"

Shrine.storages = {
  cache: Shrine::Storage::FileSystem.new("public", prefix: "uploads/cache"), # temporary
  store: Shrine::Storage::FileSystem.new("public", prefix: "uploads"),       # permanent
}

Shrine.plugin :activerecord           # loads Active Record integration
Shrine.plugin :cached_attachment_data # enables retaining cached file across form redisplays
Shrine.plugin :restore_cached_data    # extracts metadata for assigned cached files

Next, add the <name>_data column to the table you want to attach files to. For an "image" attachment on a photos table this would be an image_data column:

$ rails generate migration add_image_data_to_photos image_data:text # or :jsonb

If using jsonb consider adding a gin index for fast key-value pair searchability within image_data.

Now create an uploader class (which you can put in app/uploaders) and register the attachment on your model:

class ImageUploader < Shrine
  # plugins and uploading logic
end

class Photo < ActiveRecord::Base
  include ImageUploader::Attachment(:image) # adds an `image` virtual attribute
end

In our views let's now add form fields for our attachment attribute that will allow users to upload files:

<%= form_for @photo do |f| %>
  <%= f.hidden_field :image, value: @photo.cached_image_data, id: nil %>
  <%= f.file_field :image %>
  <%= f.submit %>
<% end %>

When the form is submitted, in your controller you can assign the file from request params to the attachment attribute on the model:

class PhotosController < ApplicationController
  def create
    Photo.create(photo_params) # attaches the uploaded file
    # ...
  end

  private

  def photo_params
    params.require(:photo).permit(:image)
  end
end

Once a file is uploaded and attached to the record, you can retrieve the file URL and display it on the page:

<%= image_tag @photo.image_url %>

See the Getting Started guide for further documentation.

Shrine was heavily inspired by Refile and Roda. From Refile it borrows the idea of "backends" (here named "storages"), attachment interface, and direct uploads. From Roda it borrows the implementation of an extensible plugin system.

• Paperclip
• CarrierWave
• Dragonfly
• Refile
• Active Storage

Please refer to the contributing page.

Everyone interacting in the Shrine project’s codebases, issue trackers, and mailing lists is expected to follow the Shrine code of conduct.

The gem is available as open source under the terms of the MIT License.