The Roda Ruby framework (my presentation on our local Ruby meetups)

01.md

Roda

• Web framework (on top of Rack)

• Forked from Cuba

• Core + Plugins

  • Core: 440 LOC
  • Total: 3200 LOC

• In my opinion the best framework for JSON APIs

  • (Rails, Sinatra, Grape, Cuba, Lotus, Webmachine, Pliny)

02.rb

require "roda"

Roda.route { "" }

Roda.app # Rack application

03.rb

require "roda"

class App < Roda
  # GET /hello
  route do |r|
    r.get "hello" do
      "Hello world!"
    end
  end
end

04.rb

require "roda"

class App < Roda
  # GET /foo/bar/baz
  route do |r|
    # "/foo/bar/baz"
    r.on "foo" do
      # "/bar/baz"
      r.on "bar" do
        # "/baz"
        r.get "baz" do
          # ""
          "request matched"
        end
      end
    end

    r.get "foo/bar/baz" do
      "request matched"
    end
  end
end

05.rb

require 'sinatra/base'

class App < Sinatra::Base
  get '/' do
    erb :index
  end

  get '/artist/:id' do
    @artist = Artist[params[:id]]
    check_access(@artist)
    erb :artist
  end

  post '/artist/:id' do
    @artist = Artist[params[:id]]
    check_access(@artist)
    @artist.update(params[:artist])
    redirect(request.path_info)
  end

  delete '/artist/:id' do
    @artist = Artist[params[:id]]
    check_access(@artist)
    @artist.destory
    redirect '/'
  end
end

06.rb

require 'roda'

class App < Roda
  plugin :render
  plugin :all_verbs

  route do |r|
    r.root do
      view :index
    end

    r.on 'artists' do
      r.is ':id' do |artist_id|
        @artist = Artist[artist_id]
        check_access(@artist)

        r.get do
          view :artist
        end

        r.post do
          @artist.update(r['artist'])
          r.redirect(request.path_info)
        end

        r.delete do
          @artist.destroy
          r.redirect '/'
        end
      end
    end
  end
end

07.rb

require "roda"

class App < Roda
  route do |r|
    r.get "quizzes" do
      if current_user
        @quizzes = current_user.quizzes
      else
        @quizzes = Quiz.search(params[:q])
      end
    end
  end
end

08.rb

require "roda"

class App < Roda
  plugin :header_matchers

  route do |r|
    r.get "quizzes", header: "Authorization" do
      @quizzes = current_user.quizzes
    end

    r.get "quizzes" do
      @quizzes = Quiz.search(params[:q])
    end
  end
end

09.rb

require "roda"

class App < Roda
  plugin :path_matchers

  route do |r|
    r.on "quizzes/:id" do
      r.get extension: "json" do
        # ...
      end

      r.get extension: "pdf" do
        # ...
      end
    end
  end
end

10.rb

require "roda"

class App < Roda
  # Legacy routes ("/foo", "/bar")
  route do |r|
    r.get "foo", "bar" do
      # ...
    end
  end
end

11.rb

require "rails"

class ArticlesController < ApplicationController
  def show
    render json: Article.find(params[:id])
  end

  def update
    render json: Article.update(params[:id], params[:article])
  end

  def delete
    render json: Article.destroy(params[:id])
  end
end

12.rb

require "roda"

class App < Roda
  plugin :json, serializer: Serializer

  route do |r|
    r.is "article/:id" do |id|
      r.get do
        Article.find(id)
      end

      r.put do
        Article.update(id, params[:article])
      end

      r.delete do
        Article.delete(id)
      end
    end
  end
end

class Serializer
  def self.call(object)
    case object
    when Hash, Array
      object.to_json
    when Sequel::Model, Sequel::Dataset
      # custom serialization
    end
  end
end

13.md

• Simplicity

  • understanding how a framework works gives your power

• Extensibility (50+ plugins)

  • JSON
  • HTTP caching
  • Streaming
  • ...

• Performance

  • empty Rails request is 10x slower than Roda's
  • around 2x faster tests

• Dynamic routing resolution

  • revolutionizes the way you write your controller code
  • Your routes are right there with their handlers (like Sinatra and Grape)

• Great for JSON APIs