# Drafting

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

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## Features

* 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

## Requirements

* Ruby 2.0.0 or newer
* ActiveRecord 4.1 or newer (including 6.0)


## Installation

Add this line to your application's Gemfile:

```ruby
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


## Usage

### Simple example

```ruby
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
```

### Linking to parent instance

```ruby
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!
```

### Hints

* `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)


## Development

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](https://rubygems.org).


## Contributing

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](https://contributor-covenant.org) code of conduct.


## License

The gem is available as open source under the terms of the [MIT License](http://opensource.org/licenses/MIT).

Based on some code from the outdated gem [drafts](https://rubygems.org/gems/drafts). Used with kind permission of Alexey Kuznetsov (@lxkuz).