Service layer

Version #1

http://slides.jcoglan.com/di-eurucamp

class Services::ConcertsClient
  def initialize(http_client)
    @http = http_client
  end

  def find(id)
    data = @http.get("/concerts/#{id}").json_data
    Models::Concert.new(data)
  end
end

class Models::Concert
  def initialize(data)
    @json_data = data
  end

  def name
    @json_data['name']
  end

  def headliners
    @json_data['performances'].
        select { |p| p['billing'] == 'headline' }.
        map { |p| Models::Artist.new(p['artist']) }
  end
end

module Services
  def self.concerts
    @concerts ||= begin
                    uri  = 'http://concerts-service'
                    http = HTTPClient.new(uri)
                    ConcertsClient.new(http)
                  end
  end
end

concert = Services.concerts.find(params[:id])