Nick Sieger-Exploring Rails 3 Through Choices

Rails 3 Through
Choices
Nick Sieger
nsieger@engineyard.com

Sunday, March 21, 2010

Nick


EY Cloud


EY Open Source

Rails JRuby

Rubinius Ruby 1.8.6


Topic


Confession


I’m not a web
developer


HTML JSON
JavaScript SQL
CSS XML
Ruby
HTTP DNS
TCP/IP Nginx
Apache FCGI Memcached

HTML JSON
JavaScript SQL
CSS
HTTP DNS
Ruby
XML

TCP/IP Nginx
Apache FCGI Memcached

Ruby
in 2010


Ruby VMs


Ruby 1.8
almost seven years old!


Ruby 1.9.2
August 2010


JRuby 1.5
April 2010


Rubinius 1.0
Q2 2010


Ruby 2.0
Let the prognostication begin


paralyzed by
choice


opinionated
software


making
choices


6 years later...


Rails 3
highlights


Rails command
$ rails newapp
create
create README
create .gitignore
create Rakefile
create config.ru
create Gemfile
create app
create app/controllers/application_controller.rb
create app/helpers/application_helper.rb
create app/models
create app/views/layouts
create config
...

Options
$ rails -h
Usage:
rails APP_PATH [options]

Options:
...
-O, [--skip-activerecord] # Skip ActiveRecord files
-T, [--skip-testunit] # Skip TestUnit files
-J, [--skip-prototype] # Skip Prototype files


Script
script/rails s
script/rails g
script/server script/rails c
script/generate
script/console rails server
rails generate
rails console


Layout


Classes
class MyController < ApplicationController
end

class MyModel < ActiveRecord::Base
end


Unobtrusive
JavaScript


JavaScript: R2
link_to "Delete Image", @image,
:confirm => "Are you sure?", :method => :delete

<a href="/images/9" onclick="if (confirm('Are you
sure?')) { var f = document.createElement('form');
f.style.display = 'none'; this.parentNode.appendChild
(f); f.method = 'POST'; f.action = this.href; var m =
document.createElement('input'); m.setAttribute('type',
'hidden'); m.setAttribute('name', '_method');
m.setAttribute('value', 'delete'); f.appendChild
(m);f.submit(); };return false;">Delete Image</a>


JavaScript: R3
link_to "Delete Image", @image,
:confirm => "Are you sure?", :method => :delete

<a href="/images/9" rel="nofollow" data-method="delete"
data-confirm="Are you sure?">Delete Image</a>


XSS Safety


XSS Safety: R2

<%= h safe_value %>

<%= unsafe_value %>


XSS Safety: R3

<%= safe_value %>

<%= raw unsafe_value %>


Routing


Routing: R2
map.connect 'products/:id',
:controller => 'catalog', :action => 'view'

map.resources :products do |products|
products.resources :comments
products.resources :sales,
:collection => { :recent => :get }
end


Routing: R3
match 'products/:id' => 'catalog#view'

resources :products do
resources :comments
resources :sales do
get :recent, :on => :collection
end
end


More

• Cleaner ActionMailer
• ActiveRecord lazy queries
• ...

First Online
RailsConf
http://bit.ly/online-railsconf-slides


APIs as Glue


Railties


The Extension API
for Rails


Decoupling
http://yehudakatz.com/2009/07/19/rails-3-the-great-decoupling/


Decoupling

ActionView

ActionController
ActiveRecord


Decoupling

ActionController ActionView ActiveRecord


Decoupling

ActionDispatch

AbstractController



Decoupling

ActionDispatch

View
AbstractController Context



Decoupling

ActionDispatch

View
ActiveModel
AbstractController Context



Encapsulate
what varies


Railties:
Conﬁguration
encapsulated


Railtie Elements

Initialization Generators

Rake Tasks Logging Events


Example

require 'rails/railtie'

class MemCacheClusterRailtie < Rails::Railtie
initializer :setup_mem_cache_cluster do |app|
app.config.cache_store = [
:mem_cache_store, 'cache1:11211', 'cache2:11211']
end
end


Rails’ Railties

ActionController:: ActionDispatch::
Railtie Railtie

ActiveRecord:: ActionMailer::
Railtie Railtie


Rails::Railtie

Rails::Application


Init: Rails 2
def process
Rails.configuration = configuration

check_ruby_version
install_gem_spec_stubs
set_load_path
add_gem_load_paths

require_frameworks
set_autoload_paths
add_plugin_load_paths
load_environment
preload_frameworks

initialize_encoding
initialize_database

initialize_cache
initialize_framework_caches

initialize_logger
initialize_framework_logging

initialize_dependency_mechanism

load_application_initializers

# the framework is now fully initialized

Init: Rails 2
after_initialize

# Setup database middleware after initializers have run
initialize_database_middleware

# Prepare dispatcher callbacks and run 'prepare' callbacks
prepare_dispatcher

# Routing must be initialized after plugins to allow the former to extend the routes
initialize_routing

# Observers are loaded after plugins in case Observers or observed models are modified by
plugins.
load_observers

# Load view path cache
load_view_paths

# Load application classes
load_application_classes

# Disable dependency loading during request cycle
disable_dependency_loading

# Flag initialized
Rails.initialized = true
end


Init: Rails 3

class Rails::Application
def initialize!
run_initializers(self)
self
end
end


rails newapp --skip-activerecord

ActiveRecord::Railtie is not loaded

No AR-related conﬁg or generators

Use Railtie to:

• Modify conﬁguration/init
• Add Rake tasks
• Add generators

Rack
• Deserves a talk by itself
• HTTP request pipeline API
• See Ryan Tomayko’s slides from
Online RailsConf


ActiveModel


codiﬁes contract
between
controller
and model

Contract
class Model
def to_model; ...; end
def to_key; ...; end
def to_param; ...; end
def valid?; ...; end
def persisted?; ...; end
def self.model_name; ...; end
def errors; ...; end
end


class ModelLintTest < Test::Unit::TestCase
def setup
@model = Model.new
end

include ActiveModel::Lint::Tests
end


Validations
class SimpleModel
include ActiveModel::Validations

# => Model#valid?, Model#errors
# plus validation framework
end


class IceCream
include ActiveModel::Validations
attr_accessor :flavour
validates_presence_of :flavour
end

ic = IceCream.new
ic.valid? # => false
ic.errors.full_messages
# => ["Flavour can't be blank"]

ic.flavour = "vanilla"
ic.valid? # => true


AMo Modules
ActiveModel::Callbacks
- before/after hooks
ActiveModel::Dirty
- dirty attribute tracking
ActiveModel::Errors
- #errors
ActiveModel::Serialization
- #to_xml, #to_json, etc.
ActiveModel::Translation
- I18n for model attributes
ActiveModel::Validations
- Full validations framework
See ActiveModel RDoc comments for more info

Putting it together


JRuby

3

Explore Rails 3
for yourself!


Photo Credits
• http://www.flickr.com/photos/henrybloomfield/2615837191/

• http://www.flickr.com/photos/mountainbread/2528179567/

• http://www.flickr.com/photos/aai/3712515230/

• http://www.flickr.com/photos/mikeschinkel/2703438152/


Nick Sieger-Exploring Rails 3 Through Choices

Recommended

Recommended

More Related Content

Similar to Nick Sieger-Exploring Rails 3 Through Choices

Similar to Nick Sieger-Exploring Rails 3 Through Choices (20)

More from ThoughtWorks

More from ThoughtWorks (20)

Recently uploaded

Recently uploaded (20)

Nick Sieger-Exploring Rails 3 Through Choices