Active Storage

Active Storage makes it simple to upload and reference files in cloud sites, like Amazon S3 or Google Cloud Storage, and attach those files to Active Records. It also provides a disk site for testing or local deployments, but the focus is on cloud storage.

Example

One attachment:

class User < ApplicationRecord
  has_one_attached :avatar
end

user.avatar.attach io: File.open("~/face.jpg"), filename: "avatar.jpg", content_type: "image/jpg"
user.avatar.exist? # => true

user.avatar.purge
user.avatar.exist? # => false

user.avatar.url(expires_in: 5.minutes) # => /rails/blobs/<encoded-key>

class AvatarsController < ApplicationController
  def update
    Current.user.avatar.attach(params.require(:avatar))
    redirect_to Current.user
  end
end

Many attachments:

class Message < ApplicationRecord
  has_many_attached :images
end

<%= form_with model: @message do |form| %>
  <%= form.text_field :title, placeholder: "Title" %><br>
  <%= form.text_area :content %><br><br>
  
  <%= form.file_field :images, multiple: true %><br>
  <%= form.submit %>
<% end %>

class MessagesController < ApplicationController
  def create
    message = Message.create! params.require(:message).permit(:title, :content)
    message.images.attach(params[:message][:images])
    redirect_to message
  end
end

Configuration

Add require "active_storage" to config/application.rb and create a config/initializers/active_storage_sites.rb with the following:

Todos

• Strip Download of its resposibilities and delete class
• Proper logging
• Convert MirrorSite to use threading
• Read metadata via Marcel?
• Copy over migration to app via rake task
• Add Migrator to copy/move between sites
• Explore direct uploads to cloud
• Extract VerifiedKeyWithExpiration into Rails as a feature of MessageVerifier

License

Active Storage is released under the MIT License.