A Lotus::View sneak peek: Lotus::Presenter

lotus_presenter.rb

module Lotus
  module Presenter
    def initialize(object)
      @object = object
    end

    protected
    def method_missing(m, *args, &blk)
      if @object.respond_to?(m)
        @object.__send__ m, *args, &blk
      else
        super
      end
    end
  end
end

class Map
  attr_reader :locations

  def initialize(locations)
    @locations = locations
  end

  def location_names
    @locations.join(', ')
  end
end

class MapPresenter
  include Lotus::Presenter

  def count
    locations.count
  end

  def location_names
    super.upcase
  end

  def inspect_object
    @object.inspect
  end
end

map = Map.new(['Rome', 'Boston'])
presenter = MapPresenter.new(map)

# access a map method
puts presenter.locations # => ['Rome', 'Boston']

# access presenter concrete methods
puts presenter.count # => 1

# uses super to access original object implementation
puts presenter.location_names # => 'ROME, BOSTON'

# it has private access to the original object
puts presenter.inspect_object # => #<Map:0x007fdeada0b2f0 @locations=["Rome", "Boston"]>

@ cheapRoc The way I use presenters are to instantiate them in the view.

require 'lotus/view'

module Dashboard
  class Index
    include Lotus::View

    def map
      MapPresenter.new(...)
    end
  end
end

and use in the template:

<p><%= map.location_names %></p>