Presenter that works with Rails

Presenter.rb

#app/presenters/article_presenter
module ArticlePresenter
  def fancy_name
  end
end

#app/presenters/comment_presenter
module CommentPresenter
  def fancy_name
  end
  def body
    body # shows the complete body text on the show page
  end
end

#app/presenters/comment_index_presenter
module CommentIndexPresenter
  def author
  end

 def body
   attributes['body'] # shows a shorter version of the body text on the index page
 end
end



#app/presenters/other_comment_presenter
module OtherCommentPresenter
  def fancy_name
  end
end

#app/presenters/statistic_presenter
module StatisticPresenter
  def ranking
    (attributes['ranking'] == 0) ? nil : attributes['ranking']
  end

  def profit
    "%.f" % attributes['profit'].round
  end
end

#app/helpers/presenter_helper
module PresenterHelper
  def present_each (collection, presenter_module = nil)
    collection.each do |resource|
      presenter_module ||= "#{resource.class}Presenter".constantize
      yield resource.extend(presenter_module)
    end
  end
end

#app/controllers/articles
def index
  @articles = Article.all
end

def show
  @article = Article.find(params[:id]).extend(ArticlePresenter)
end

View.erb

#app/views/articles/show
<% present_each(@article.comments) do |comment| %>
  <%= comment.fancy_name %>
<% end %>

<% present_each(@article.comments, OtherCommentPresenter) do |comment| %>
  <%= comment.fancy_name %>
<% end %>

#app/views/articles/index
<% present_each(@articles) do |article| %>
 <%= article.fancy_name %>
<% end %>