Module: Livery::Controller

Defined in:
lib/livery/controller.rb

Defined Under Namespace

Modules: ClassMethods

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(base) ⇒ Object 



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# File 'lib/livery/controller.rb', line 3

def self.included(base)
  base.extend(ClassMethods)
end

Instance Method Details

#present(hsh) ⇒ Object

Pass presenters to the view. Must be used with the class method use_presenters!.

hsh A hash whose keys define the names of variables used in the view, and values the objects that will be presented. Each object must either be a presenter, or have a corresponding presenter class; e.g., a Post model should have a PostPresenter class. If an enumerable is passed, each object within is mapped over. An exception is raised otherwise.

Examples

present will wrap non-presenter objects with their presenter classes. Here, the Post object is wrapped with a PostPresenter:

# app/controllers/posts_controller.rb
class PostsController < ApplicationController
  include Livery::Controller
  use_presenters!

  def show
    post = Post.find(params[:id])

    present(post: post)
  end
end

This is equivalent to (without using use_presenters!):

# app/controllers/posts_controller.rb
class PostsController < ApplicationController
  def show
    post = Post.find(params[:id])

    @post = PostPresenter.new(post)
  end
end

It can handle enumerables:

# app/controllers/posts_controller.rb
class PostsController < ApplicationController
  include Livery::Controller
  use_presenters!

  def index
    posts = Post.all

    # Equivalent to:
    # @posts = posts.map { |post| PostPresenter.new(post) }
    present(posts: posts)
  end
end

And presenter objects will not be re-wrapped:

# app/controllers/posts_controller.rb
class PostsController < ApplicationController
  include Livery::Controller
  use_presenters!

  def show
    post_presenter = PostPresenter.new(current_user.post)

    # Equivalent to:
    # @post = post_presenter
    present(post: post_presenter)
  end
end

Presenter classes are found via a simple naming convention; an object of some class Model will be wrapped with a ModelPresenter. If a corresponding presenter class is not found, an error is raised.



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# File 'lib/livery/controller.rb', line 113

def present(hsh)
  @_presenters ||= {}
  hsh.each_with_object(@_presenters) do |(k, v), acc|
    acc[k] = Livery::Presenter.to_presenter(v)
  end
end