Pragma on Rails

This gem provides Ruby on Rails integration for the Pragma architecture.

Installation

Add this line to your application's Gemfile:

gem 'pragma-rails'

And then execute:

$ bundle

Or install it yourself as:

$ gem install pragma-rails

Usage

Generators

This gem provides a pragma:resource generator for creating a new resource with the default CRUD operations:

$ rails g pragma:resource image
      create  app/resources/api/v1/image
      create  app/resources/api/v1/image/contract/base.rb
      create  app/resources/api/v1/image/contract/create.rb
      create  app/resources/api/v1/image/contract/update.rb
      create  app/resources/api/v1/image/decorator/instance.rb
      create  app/resources/api/v1/image/decorator/collection.rb
      create  app/resources/api/v1/image/operation/create.rb
      create  app/resources/api/v1/image/operation/destroy.rb
      create  app/resources/api/v1/image/operation/index.rb
      create  app/resources/api/v1/image/operation/show.rb
      create  app/resources/api/v1/image/operation/update.rb
      create  app/resources/api/v1/image/policy.rb
      create  app/controllers/api/v1/images_controller.rb
      create  spec/requests/api/v1/images_spec.rb
       route  namespace :api do
    namespace :v1 do
      resources :images, only: %i(index show create update destroy)
    end
  end

You can also specify an API version (the default is 1):

$ rails g pragma:resource image -v 2
      create  app/resources/api/v2/image
      create  app/resources/api/v2/image/contract/base.rb
      create  app/resources/api/v2/image/contract/create.rb
      create  app/resources/api/v2/image/contract/update.rb
      create  app/resources/api/v2/image/decorator.rb
      create  app/resources/api/v2/image/operation/create.rb
      create  app/resources/api/v2/image/operation/destroy.rb
      create  app/resources/api/v2/image/operation/index.rb
      create  app/resources/api/v2/image/operation/show.rb
      create  app/resources/api/v2/image/operation/update.rb
      create  app/resources/api/v2/image/policy.rb
      create  app/controllers/api/v2/images_controller.rb
      create  spec/requests/api/v2/images_spec.rb
       route  namespace :api do
    namespace :v2 do
      resources :images, only: %i(index show create update destroy)
    end
  end

Controllers

Pragma::Rails::Controller gives your controller the ability to run Pragma operations:

module API
  module V1
    class ArticlesController < ApplicationController
      include Pragma::Rails::Controller

      def create
        run API::V1::Article::Operation::Create
      end
    end
  end
end

In the example above, ArticlesController#create will run the API::V1::Article::Operation::Create operation and respond with the status code, headers and resource returned by the operation.

By default, the #params method will be used as the operation's parameters and #current_user, if available, will be used as the operation's user. You can override these defaults by overriding the #operation_params and #operation_user methods in your controller:

module API
  module V1
    class ArticlesController < ApplicationController
      include Pragma::Rails::Controller

      def create
        run API::V1::Article::Operation::Create
      end

      private

      def operation_params
        params.merge(my_additional: 'param')
      end

      def operation_user
        User.authenticate_from params
      end
    end
  end
end

Resource Controllers

Resource controllers (provided by the Pragma::Rails::ResourceController module) abstract even more of the logic behind your controllers by inferring the operations supported by a resource and automatically providing controller actions that run them.

With a resource controller, the example above could be rewritten as:

module API
  module V1
    class ArticlesController < ApplicationController
      include Pragma::Rails::ResourceController

      private

      def operation_params
        params.merge(my_additional: 'param')
      end

      def operation_user
        User.authenticate_from params
      end
    end
  end
end

You will still have to define a route to your #create action, of course, but you don't have to write the action anymore!

This works with any actions, not only the default CRUD actions defined by Rails. So, for instance, if you have an API::V1::Article::Operation::Publish operation, a #publish action will be accessible in the API::V1::ArticlesController controller.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/pragmarb/pragma-rails.

License

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