Mid-Hudson Valley Linux Users Group Ruby on Rails Web Development is Fun Again MHVLUG Meeting Jan 7 th 2009 Sean Dague sean.dague.net

Mid-Hudson Valley Linux Users Group Challenges of Tonight's Talk Installing Rails Creating a Scaffold AJAX Effects Deploying with Passenger ActiveRecord Basics Validators ActiveSuppor t MVC ActiveRecord Magic Migrations Unit Testing REST Web Services RESTful Authentication Layout s RJS Templates XML Builder Object Relationships acts_as_tre e acts_as_list Wrapping Legacy Databases DateTime mixins Activ e r Rails Plugins Git Support LDAP Support xml-rpc background.rb

Mid-Hudson Valley Linux Users Group Where did it come from? "37Signals is “sexy” - one of its founders is the Scandinavian rockstar behind Ruby on Rails, David Heinemeier Hansson. On the tech industry sexometer, 37Signals is like Spinal Tap- they have a special cool amplifier that goes up to 11." - James Governor, Redmonk.com

Mid-Hudson Valley Linux Users Group The Rails Motto DRYDRY on't epeat ourself

Mid-Hudson Valley Linux Users Group Model / View / Controller pattern

Mid-Hudson Valley Linux Users Group Nuts and Bolts I promise we'll get to fun stuff shortly

Mid-Hudson Valley Linux Users Group Rails Installation ● It may come with your distribution – Using that often makes the most sense – Ubuntu 8.10 ships rails There is a layouts bug which is fixed in ● Instant Rails - easy on Windows ● And yes, it works great on Mac as well

Mid-Hudson Valley Linux Users Group Installing Rails on Ubuntu # gem install rails -v "=2.1.2" Successfully installed activesupport Successfully installed activerecord Successfully installed actionpack Successfully installed actionmailer Successfully installed activeresource Successfully installed rails (documentation installation)

Mid-Hudson Valley Linux Users Group The Sample Application MHVLUG Event Calendar...created live

Mid-Hudson Valley Linux Users Group Some Ruby-isms you'll see ● :event is 'event' - ':' auto quotes a string ● parens are not required if unambiguous – debugger - is a function – link_to 'Show', event - is a function with 2 params is not an array, it is an instance scope ● respond_to do |format|... ● end ● respond_to returns an iterator, the do block is called once for every item in the iterator. format is the object of that iteration.

Mid-Hudson Valley Linux Users Group Rails loves that escaping Event.find(:first, :conditions => ["name=?", name]) Why do we care?

Mid-Hudson Valley Linux Users Group

Your First Rails Application # rails -d sqlite3 mhvlug-event... # cd mhvlug-event #./script/server => Booting WEBrick... => Rails application started on => Ctrl-C to shutdown server; call with --help for options [ :53:19] INFO WEBrick [ :53:19] INFO ruby ( ) [i486-linux] [ :53:19] INFO WEBrick::HTTPServer#start: pid=27722 port=3000

Mid-Hudson Valley Linux Users Group Creating Your First Model/Scaffold #./script/generate scaffold event name:string description:text location:string start:datetime end:datetime... # rake db:migrate

Mid-Hudson Valley Linux Users Group Exploring that Scaffold

Mid-Hudson Valley Linux Users Group Flavor of Rails class Project < ActiveRecord::Base belongs_to :portfolio has_one :project_manager has_many :milestones has_many :deliverables, :through => :milestones validates_presence_of :name, :description validates_acceptance_of :non_disclosure_agreement validates_uniqueness_of :short_name end

Mid-Hudson Valley Linux Users Group Migrations

Mid-Hudson Valley Linux Users Group Adding Layout

Mid-Hudson Valley Linux Users Group Rails Conventions ● Objects are singular, database tables are plural – Person objects stored in people table ● Database tables have primary key named id, which is an auto incrementing integer ● Foreign keys defined by object_id.

Mid-Hudson Valley Linux Users Group Buy These Books!

Mid-Hudson Valley Linux Users Group NetBeans - Rails IDE

Mid-Hudson Valley Linux Users Group Advanced Topics ● Wrapping Legacy Data ● Adding User Authentication - restful_authentication ● Consuming Web Services - Active Resource ● Deployment - passenger / aka mod_rails ● Rails Debugger ● Rails Console ● restful_authentication_tutorial

Mid-Hudson Valley Linux Users Group Things I love about Rails ● Migrations ● Layouts ● Deep REST integration ● Secure by default ● Built in testing ● Rails is not synthetic ● 30 minutes to add a new feature