Frozen Rails Slides

Rails 3: With a Vengeance Friday, May 7, 2010

Friday, May 7, 2010

Rails 3: With a Vengeance Friday, May 7, 2010

Friday, May 7, 2010

New talk title: Friday, May 7, 2010

DHH introduced Rails 3 at last RailsConf. He likes whoppers. I actually hate burger king entirely. I’m not sure how anybody can eat there. But that’s OK, because I can make my own rails burger the way I like Rails 3: Tasty Burgers Friday, May 7, 2010

Friday, May 7, 2010

Skill Friday, May 7, 2010

A lot like Rails 2.3 We tried really hard to not break any 2.x APIs unless it was really deemed necessary or a big win. Friday, May 7, 2010

Only surface level stuff is the same. A lot under the hood has changed and there are a lot more features. I obviously can’t cover everything in depth in an hour, so I’m going to gloss over a lot and you can all look into details later. But not really... Friday, May 7, 2010

What hasn’t changed Quick Refresher Friday, May 7, 2010

MVC Friday, May 7, 2010

REST Friday, May 7, 2010

The router / controller / ActiveRecord model is still optimized for organizing your application in terms of Resources Resources Friday, May 7, 2010

Controllers Friday, May 7, 2010

Some changes (Arel, query api - Not going to really cover this) General ideas are the same associations ActiveRecord pattern ActiveRecord Friday, May 7, 2010

Migrations Friday, May 7, 2010

So, what did change? Friday, May 7, 2010

There were some t weaks to the default File structure, mostly in the config directory. This is what you get when you generate a new Rails 3 app File structure One big thing about Rails 3 is that the app file structure is not sacred, it’s just a convention, not obligation Friday, May 7, 2010

conﬁg.ru Rails 3 is pure Rack. When you start an app, it evaluates config.ru, which is a rack convention. If this file is there, all rack compatible rack servers know what to do. Could putfile is used by Rack-based(could even put a # This middleware or whatever here servers fullto start in this one file). # Rails app the application. require ::File.expand_path( '../config/environment', __FILE__) run AwesomeBlog::Application Who doesn’t know what Rack is? Could put middleware or whatever here (could even put a full Rails app in this one file). Friday, May 7, 2010

conﬁg.ru That’s specifically the line that rack is looking for. The constant is a Rack app that encapsulates #everything related to the entire rails application that This file is used by Rack-based servers #we’re building the application. to start require ::File.expand_path( '../config/environment', __FILE__) run AwesomeBlog::Application Friday, May 7, 2010

conﬁg/application.rb This is the file that defines the application object from the last slide. require File.expand_path('../boot', __FILE__) Let’s look at some key components require 'rails/all' Bundler.require(:default, Rails.env) if defined?(Bundler) module AwesomeBlog class Application < Rails::Application config.encoding = "utf-8" config.filter_parameters += [:password] end end Friday, May 7, 2010

conﬁg/application.rb require File.expand_path('../boot', __FILE__) require 'rails/all' Bundler.require(:default, Rails.env) if defined?(Bundler) module AwesomeBlog class Application < Rails::Application config.encoding = "utf-8" config.filter_parameters += [:password] end end Friday, May 7, 2010

conﬁg/application.rb require File.expand_path('../boot', __FILE__) require 'rails/all' Bundler.require(:default, A Rack App! Rails.env) if defined?(Bundler) module AwesomeBlog class Application < Rails::Application config.encoding = "utf-8" config.filter_parameters += [:password] end end Friday, May 7, 2010

Contains all application specific information. Takes the “in the sky” constants / globals that were needed for a rails 2.3 application and encapsulates them. Routes, Config, Middleware, Initializers Application Object One day, we’ll have many application objects in one process. Ruby summer of code project to get this done. Friday, May 7, 2010

conﬁg/application.rb require File.expand_path('../boot', __FILE__) require 'rails/all' Bundler.require(:default, Rails.env) if defined?(Bundler) module AwesomeBlog class Application < Rails::Application config.encoding = "utf-8" config.filter_parameters += [:password] end end Friday, May 7, 2010

conﬁg/boot.rb require 'rubygems' # Set up gems listed in the Gemfile. gemfile = File.expand_path('../../Gemfile', __FILE__) begin ENV['BUNDLE_GEMFILE'] = gemfile require 'bundler' Bundler.setup rescue Bundler::GemNotFound => e STDERR.puts e.message STDERR.puts "Try running `bundle install`." exit! end if File.exist?(gemfile) Friday, May 7, 2010

conﬁg/boot.rb require 'bundler' Bundler.setup Friday, May 7, 2010

Bundler is a tool we built to manage gem dependencies. As it turns out, as rails applications grow, dependencies become painful to deal with. Many years in the making. Many iterations. It grew out of projects that had many complicate dependencies and it was basically impossible to deal with it all by hand Friday, May 7, 2010

Gemﬁle It all starts here. This file is located at the root of the application. All gem dependencies will be listed here. So far our app is small, so we only depend on rails itself (note the version is the one that we are currently working with) and also we have a dependency on sqlite since that’s the database that we’re using. source 'http://rubygems.org' gem 'rails', '3.0.0.beta3' gem 'sqlite3-ruby', :require => 'sqlite3' Friday, May 7, 2010

Step t wo is to run the “bundle install” command. * Checks gems already on system * Downloads what is missing $ bundle install Friday, May 7, 2010

No step 3 Friday, May 7, 2010

What are the major wins that we get from using bundler? Wins: Friday, May 7, 2010

Dependencies in applications will evolve a lot throughout the life of an application Ruby is maturing. There are a LOT of gems out there that you’ll be wanting to use. Bundler makes doing it easy. Easy to update dependencies Friday, May 7, 2010

Gemﬁle What happens if you want to update your application to the latest version of rails? source 'http://rubygems.org' gem 'rails', '3.0.0.beta3' gem 'sqlite3-ruby', :require => 'sqlite3' Friday, May 7, 2010

Gemﬁle You’re done. All child dependencies will be handled for you. The same goes if you want to roll back to a previous version. Just change the Gemfile source 'http://rubygems.org' gem 'rails', '3.0.0' gem 'sqlite3-ruby', :require => 'sqlite3' Friday, May 7, 2010

You know all your dependencies are accounted for and you won’t be surprised when you deploy. Bundler does not let you use a gem if it is not listed in the Gemfile. So, you can’t accidentally forget to install a gem on the ser ver when you deploy. Isolation Friday, May 7, 2010

Your Gemfile accounts for all gems. You share your app with other developers. They run `bundle install` and they’re good to go. Bundler tracks all child dependencies as well as top level app dependencies Sharing Come back to a project 3 months later. What version of UUID was I using? (yeah, that broke deploys) Nokogiri? Designers Friday, May 7, 2010

Anybody ever hit the “can’t activate gem foo, already activated foo at another version error”? No conﬂicts Friday, May 7, 2010

Without Bundler Friday, May 7, 2010

Friday, May 7, 2010

Step 1) Vendor Rails + Rack The Solution! Friday, May 7, 2010

Step 1) Modify the Rails source The Solution! Friday, May 7, 2010

While we’re on the topic of picard.... Friday, May 7, 2010

Friday, May 7, 2010

http://gembundler.com Friday, May 7, 2010

Unobtrusive Javascript Friday, May 7, 2010

In Rails 2.3, all view helpers that required JS would spew out a whole bunch of Prototype specific javascript inline. This is bad. Helpers do not generate JS anymore Friday, May 7, 2010

Rails 3.0 helpers will now only output HTML. All required information will be added to the HTML tags via data-* Custom data-* attributes were added in HTML5, but they work in all old and busted (IE 6). <%= link_to "hello", hello_path, :remote => true %> <a href="/hello" data-remote="true">hello</a> Friday, May 7, 2010

public/javascripts/rails.js $(document.body).observe("click", function(event) { // .... var element = event.findElement( "a[data-remote]"); if (element) { handleRemote(element); event.stop(); return true; } The javascript that handles all the data-* attributes is in rails.js // .... }); Friday, May 7, 2010

Who uses jQuery? Using jQuery? http://github.com/rails/jquery-ujs Rails will ship with the Prototype driver, but you can just drop in the jquery driver at public/javascripts/rails.js We maintain it and it’s on github at the URL. You can finally easily completely rid your Rails app of all Prototype Friday, May 7, 2010

public/javascripts/rails.js $('a[data-remote],input[data-remote]'). live('click', function (e) { $(this).callRemote(); e.preventDefault(); }); This is the code that is in the jQuery rails.js driver Friday, May 7, 2010

Other wins too. Pick your JS framework when you write JS, not when you generate your Rails app. Friday, May 7, 2010

Just JS events being triggered. You can easily replace specific default behavior. There are events that are triggered that you can bind to. ajax:before, ajax:after, etc... Customizable Friday, May 7, 2010

Rails is like a toolkit to build rails. Think about it. Everything is a “plugin” Friday, May 7, 2010

ActiveRecord? Friday, May 7, 2010

Plugin! Friday, May 7, 2010

ActionController? Friday, May 7, 2010

TestUnit Friday, May 7, 2010

ActiveResource? Friday, May 7, 2010

... Friday, May 7, 2010

You can build plugins too. Friday, May 7, 2010

Railtie is a class that integrates a library with rails. Look at how ActiveRecord does it. Look at how everything else does it. Railtie When we built Rails 3, we didn’t add hook points for all these other libraries after the fact. We made hooks for ourselves to use, which has the nice side effect of other libraries being able to use them. RSpec, DataMapper, HAML, etc... all use the same hooks that Rails uses Friday, May 7, 2010

Conﬁguration Rake Tasks Generator Overrides You actually rarely need a Railtie to integrate with Rails. Railties are for a few specific things. Initializers Friday, May 7, 2010

Conﬁguration Rake Tasks Generator Overrides Provide configuration opportunities to Rails applications config.active_record in config/application.rb Initializers If you want to provide default config values, you need a Railtie Friday, May 7, 2010

Conﬁguration Rake Tasks Generator Overrides All ActiveRecord’s rake tasks are in it’s Railtie, which means that when AR isn’t required, the rake tasks go away. Initializers If you want to easily provide Rake tasks to a Rails app, you need a Railtie Friday, May 7, 2010

If you want to hook in to: * rails generate controller Foo * rails generate model Conﬁguration Foo you need a Railtie. RSpec uses this to provide the same level of integration thatRake Tasks TestUnit gets Generator Overrides Initializers Friday, May 7, 2010

If you want to hook into the initialization Conﬁguration cycle of a Rails application, you’ll need a Railtie Rake Tasks Generator Overrides Initializers Friday, May 7, 2010

HTML escaping Friday, May 7, 2010

Rails 2.3 <p> <%= h @comment.title %> (by <%= h @comment.author.username %>) </p> <%= simple_format h(@comment.body) %> This is what a view might have looked in Rails 2.3 Friday, May 7, 2010

Rails 2.3 <p> <%= h @comment.title %> (by <%= h @comment.author.username %>) </p> <%= simple_format h(@comment.body) %> If you forget one spot, you’re site gets hacked ... I’m sure everybody here has missed at least 1 spot to escape Friday, May 7, 2010

Rails 3.0 New! No more pesky h() <p> <%= @comment.title %> (by <%= @comment.author.username %>) </p> <%= simple_format(@comment.body) %> Now, you don’t have to worry about escaping anything anymore. Rails does it for you. Friday, May 7, 2010

XSS Protection by default Friday, May 7, 2010

app/helpers/application_helper.rb def escaped(str) Simply returning a string a str string will be escaped. end If you don’t want a string to be def not_escaped(str) escaped, you just mark it as str.html_safe html_safe and it won’t be end modified by Rails. Friday, May 7, 2010

Block helpers Friday, May 7, 2010

Rails 2.3 This is what block <% form_for @post do |f| %> helpers might look <%= f.text_field :title %> like in 2.3 <% end %> <% box do %> <p>Hello World!</p> <% end %> Friday, May 7, 2010

Rails 2.3 def box(&block) This is the content = "<div class='box'>" << capture(&block) << "</div>" implementation. if block_called_from_erb? I’m not even going to concat(content) really talk about this, else Just notice that it’s content crazy end end Most of this is needed to make the helper work in and outside of ERB. Friday, May 7, 2010

Rails 2.3 Outputs method’s return value <% form_for @post do |f| %> <%= f.text_field :title %> <% end %> Ignores method’s return value <% box do %> <p>Hello World!</p> The reason why you <% end %> need the craziness is because of how ERB works. Friday, May 7, 2010

Rails 3.0 <%= form_for @post do |f| %> In Rails 3.0 block helpers <%= f.text_field :title %> have become consistent <% end %> with ERB. form_for will actually <%= box do %> output content to the <p>Hello World!</p> view, aka, the form tags. <% end %> So, now you use %= The same goes for custom block helpers Friday, May 7, 2010

Rails 3.0 def box(&block) All you do now for "<div class='box'>" block helpers is return the string that you "#{capture(&block)}" want outputted to the "</div>" view. end Block helpers aren’t special anymore. They work the same inside and outside ERB Friday, May 7, 2010

Rails 3.0 def box(&block) "<div class='box'>" "#{capture(&block)}" "</div>".html_safe end Friday, May 7, 2010

Massive API overhaul. Router Friday, May 7, 2010

You don’t have to rush to update your route file to get on Rails 3.0 The old DSL will probably stop working in Rails 3.1 or 3.2, but you have time before that happens. Old DSL still works, just deprecated. Friday, May 7, 2010

Matching map.connect "/posts", :controller => :posts, :action => :index Friday, May 7, 2010

Matching map.connect "/posts", :controller => :posts, :action => :index match "/posts" => "posts#index" posts#index is short hand for specifying the controller and action. It’s just much easier to write. Friday, May 7, 2010

Optional Segments match "/posts(/:page)" => "posts#index" Will match a request to /posts, and a request to /posts/5 if page is not there, params[:page] will be nil, if it is present in the request, the param will be set. Friday, May 7, 2010

Defaults You can specify default parameters. If the page segment is not in the Request, params[:page] will be set to 1 match "/posts(/:page)" => "posts#index", :defaults => { :page => 1 } Friday, May 7, 2010

Named Routes The same helpers are available. * posts_path * posts_url match "/posts(/:page)" => "posts#index", :defaults => { :page => 1 }, :as => "posts" Friday, May 7, 2010

Scopes Let’s you set the same options to a group of routes. Almost anything can be scoped. Friday, May 7, 2010

Path Scopes /admin/posts scope :path => "/admin" do match "/posts" => "posts#index" match "/users" => "users#index" end Friday, May 7, 2010

Path Scopes Paths are probably the most common item to scope on, so it’s the default. scope "/admin" do match "/posts" => "posts#index" match "/users" => "users#index" end Friday, May 7, 2010

Module Scope Routes to Admin::PostsController / Admin::UsersController scope :module => "admin" do match "/posts" => "posts#index" match "/users" => "users#index" end Friday, May 7, 2010

Both namespace "admin" do match "/posts" => "posts#index" match "/users" => "users#index" end Friday, May 7, 2010

HTTP Methods Routing by specific HTTP methods Friday, May 7, 2010

POST Request match "/posts" => "posts#index", :via => "delete" Any HTTP method can be used here Friday, May 7, 2010

Scoping scope "/posts" do controller :posts do get "/" => :index end end Friday, May 7, 2010

Scoping scope "/posts" do Yet another controller :posts do shorthand get "/" => :index end end Friday, May 7, 2010

Scoping scope "/posts" do get URL controller :posts do get "/" => :index end end Friday, May 7, 2010

Scoping get / post / post / delete methods are shorthands for :via => “get” This method can be used anywhere in the routes file get "/posts" => "posts#index" Friday, May 7, 2010

Constraints Friday, May 7, 2010

Regexp Constraint get "/:id" => "posts#index", :id => /d+/ Friday, May 7, 2010

Regexp Constraint Constraints on arbitrary methods of Request object. Will use the “user_agent” method on the Request object get "/posts" => "posts#mobile", :user_agent => /iPhone/ Friday, May 7, 2010

Defaults + Constraints Friday, May 7, 2010

Constraint + Default How does it not get confused? If you use a Regex on as the value of the hash, it is a constraint, other wise, it is a default get "/posts" => "posts#mobile", :user_agent => /iPhone/, :mobile => true Friday, May 7, 2010

Object Constraints Any object that responds to matches? can be a router constraint class DubDubConstraint def self.matches?(request) request.host =~ /^(www.)/ # true / false end end get "/" => "posts#index", :constraints => DubDubConstraint Friday, May 7, 2010

Everything that used to be in ActionController that made sense without ActionController. There is a lot, all rack middleware. * Session * Cookies * Router * Flash * etc.. Rack Everywhere Can be used without AC and only Rack. This is the minimum requirement for “Rails” Friday, May 7, 2010

Rack You can get a rack app for any controller action PostsController.action(:index) Friday, May 7, 2010

Routing + Rack This is what happens behind the scenes in my previous examples get "/posts" => PostsController.action(:index) Friday, May 7, 2010

Routing + Rack Just a Rack app get "/posts" => PostsController.action(:index) Friday, May 7, 2010

Routing + Rack Any Rack app get "/posts" => PostsController.action(:index) Friday, May 7, 2010

Routing + Rack Sinatra app get "/posts" => MySinatraPostsApp Friday, May 7, 2010

Routing + Rack Camping app get "/posts" => MyCampingPostsApp Friday, May 7, 2010

Routing + Rack Ramaze app get "/posts" => MyRamazePostsApp Friday, May 7, 2010

Routing + Rack The possibilities are endless Any Rack app get "/posts" => MyConstantThatRespondsToCall Friday, May 7, 2010

ActionMailer Friday, May 7, 2010

It’s new Massive API overhaul I’m out of time Friday, May 7, 2010

A lot of detailed stuff about what’s new with Rails 3. * Articles * Blog posts * Screencasts * QAs * Aggregation of other Rails 3 info Friday, May 7, 2010

http://www.railsdispatch.com/posts/actionmailer Friday, May 7, 2010

Upgrading I want to mention upgrading really quick Rails 1.x apps -> 3.0 is really easy (15 minutes) Rails 2.x is a little bit harder Friday, May 7, 2010

Step 1) Generate a new app Look at the generated file structure Friday, May 7, 2010

conﬁg.ru Friday, May 7, 2010

conﬁg/* Friday, May 7, 2010

It will try to find all deprecated but still working methods as well * Router * AR API * config/* * Deprecated constants http://github.com/rails/rails_upgrade * Mail API * Known broken plugins * Helpers * But all this stuff still will work in rails 3, just will spew out deprecation notices. Friday, May 7, 2010

Questions? We have 2 other Rails core people here, they can answer questions too. Friday, May 7, 2010

Questions? Email: me@carllerche.com (I accept fan mail) Twitter: @carllerche (I’m interesting. Really!) I will tweet the slides. So make sure you are following me. Friday, May 7, 2010

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Frozen Rails Slides

by carllerche on May 07, 2010

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Frozen Rails Slides — Presentation Transcript