Dekorator

Dekorator is an opinionated way of organizing model-view code in Ruby on Rails, based on decorators.

Not production ready

Compatibility

• Ruby 2.3+
• Rails 5.0+

Installation

Add this line to your application's Gemfile:

gem "dekorator"

And then execute:

$ bundle

Getting started

Run the following command to set up your project:

$ rails generate dekorator:install

This command will create an ApplicationDecorator file.

Usage

Generate a new decorator with the decorator generator:

$ rails generate decorator user

This command will generate the following file:

class UserDecorator < ApplicationDecorator
  # include ActionView::Helpers::TextHelper
  #
  # decorates_association :posts
  #
  # def full_name
  #   [first_name, last_name].join(" ")
  # end
  #
  # def biography_summary
  #   truncate(biography, length: 170)
  # end
end

Associations

If you want to automatically decorates association for a decorated object, you have to use #decorates_association as following:

class UserDecorator < ApplicationDecorator
  decorates_association :posts

  ...
end

class PostDecorator < ApplicationDecorator
  ...
end

In this example, UserDecorator#posts will be decorated.

decorated_user = decorator(User.first)
decorated_user # => UserDecorator
decorated_user.posts.first # => PostDecorator

Specify decorator

If you want to create specific decorator or sub-decorator, you could simply specify the decorator class that should be use.

class AdminDecorator < ApplicationDecorator
end

decorated_user = decorator(User.first, with: AdminDecorator)
decorated_user # => AdminDecorator

You also could specify the decorator for associations:

class UserDecorator < ApplicationDecorator
  decorates_association :posts, ArticleDecorator

  ...
end

class ArticleDecorator < ApplicationDecorator
end

decorated_user = decorator(User.first)
decorated_user # => UserDecorator
decorated_user.posts.first # => ArticleDecorator

Compatibility

ActiveAdmin

This gem is compatible with activeadmin.

Simply use #decorate_with

# app/admin/post.rb
ActiveAdmin.register Post do
  decorate_with PostDecorator

  index do
    column :title
    column :image
    actions
  end
end

Devise

If you use device gem you may have an issue if you decorate your User model.

You must define #devise_scope as following. Devise need to manage with User model (https://github.com/plataformatec/devise/blob/369ba267efaa10d01c8dba59b09c3b94dd9e5551/lib/devise/mapping.rb#L35).

class UserDecorator < ApplicationDecorator
  ...

  def devise_scope
    __getobj__
  end
end

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.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/pantographe/dekorator. 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.

License

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

Code of Conduct

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