This Ruby gem enhances ActiveRecord::Base to save a draft version of the current instance.

• The gem stores all the data in one separate table and does not need to modify the existing tables
• It handles drafts for different models
• It allows saving draft for an instance which does not pass the validations
• A draft stores associations and virtual attributes, too
• A draft is optionally linked to a given user, so every user can manage his own drafts (invisible for the other users)
• A draft is optionally linked to a parent instance. This helps showing existing drafts in a context (e.g. message drafts for a given topic)
• Only 90 lines of code

• Ruby 2.5 or newer
• ActiveRecord 5.0 or newer (including 7.0)

Add this line to your application's Gemfile:

gem 'drafting'

And then execute:

$ bundle

Or install it yourself as:

$ gem install drafting

Finally, generate and run the migration:

$ rails g drafting:migration
$ rake db:migrate

class Message < ActiveRecord::Base
  has_drafts
end

message = Message.new content: "Let's start with a simple example."
message.save_draft(current_user)

# Time passes ...

draft = Message.drafts(current_user).first
message = draft.restore
message.save!

drafts = Message.drafts(current_user)
messages = drafts.restore_all

If you are upgrading from previous versions, simply run rails g drafting:migration again to generate the mising migration files.

Starting from 0.5.x, you will be able to save drafts under a non User model as such:

message.save_draft(author)

Starting from 0.6.x, you will be able to save metadata to your draft (eg. to label your drafts) as such:

message.save_draft(author, { title: 'Final Draft 2022-08-06' })
draft = Draft.find(message.draft_id)
draft.title # => 'Final Draft 2022-08-06'

message.update_draft(
  author,
  { content: 'New content for message' },
  {
    title: 'Final Final Draft 2022-08-06',
    version: '1.123'
  }
)
message.content # => 'New content for message'
draft = Draft.find(message.draft_id)
draft.title # => 'Final Final Draft 2022-08-06'
draft.version # => '1.123'
draft.version = '1.5'
draft.save
draft.reload.version # => '1.5'

Note that the metadata on the draft is essentially a Rails store whose keys are dynamically generated according to your application needs. They are generated on the fly via method_missing.

class Topic < ActiveRecord::Base
  has_many :messages
end

class Message < ActiveRecord::Base
  belongs_to :topic
  has_drafts parent: :topic
end

topic = Topic.create! title: 'World domination'
message = topic.messages.build content: 'First step: Get some coffee.'
message.save_draft(current_user)

# Time passes ...

draft = topic.drafts(current_user).first
# or
draft = Topic.child_drafts(current_user).first

message = draft.restore
message.save!

• save_draft is allowed only if the instance is not persisted yet
• Doing save_draft overwrites a previous draft (if there is one)
• After doing a save, the draft (if there is one) will be deleted
• The user argument can be nil if you don't want to distinguish between multiple users
• Saving draft stores the data via Marshal.dump and Marshal.load. If you don't like this or need some customization, you can override the instance methods dump_to_draft and load_from_draft (see source)

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/ledermann/drafting. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

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

Based on some code from the outdated gem drafts. Used with kind permission of Alexey Kuznetsov (@lxkuz).