Getting On Board Ruby on Rails

1
Getting On Board Ruby on Rails

• Brian Hogan and Lillian Hillis
• University of Wisconsin Eau Claire

2
Getting On Board Ruby On Rails
What's the buzz

• Framework is two years old
• New way to develop web-based applications
• Lots of converts from other languages

3
Getting On Board Ruby On Rails
When to use Rails

• New web-to-database systems
• Migrations from existing PHP, ASP, or Perl
  systems
• An alternative to non-Enterprise J2EE systems
• Systems in that gap between simple scripts and
  complex enterprise systems

4
Getting On Board Ruby On Rails
When NOT to use Rails

• Simple scripts
• Non-web projects
• Complex systems with legacy databases
• Possible to do but you will lose productivity
  gains

5
Getting On Board Ruby On Rails
How UW-Eau Claire Uses It

• Web-based administrative systems for
  administrative and academic offices
• Housing and Residence Life
• Student Health Services
• Music and Theater Arts
• Continuing Education
• Developed by student developers
• New developers every couple of years
• Team-based approach whenever possible

6
Getting On Board Ruby On Rails
Key Benefits

• Rapid prototyping
• Built-in testing
• Easy to maintain and upgrade
• Friendly user community
• Easy to learn, embrace and extend
• Its agile!

7
Getting On Board Ruby On Rails
Whos Using Rails

• Penny Arcade
• AListApart
• Gusto
• Shopify
• Strongspace
• Yakima-Herald Telegram
• Subtopic

8
(No Transcript)
9
(No Transcript)
10
Getting On Board Ruby On Rails
Rails and the MVC Pattern

• Model - View - Controller
• Rails follows this pattern very strictly
• Rails adds some extra components to this pattern

11
(No Transcript)
12
Getting On Board Ruby On Rails
Models

• Provide access to database tables
• Contain business rules
• Record CRUD (Create, Read, Update, Delete)
• An instance represents a row in a table
• Grade model instance gt one row from grades
  table

13
Model

• Models also define validations and associations
  with other models.

14
Getting On Board Ruby On Rails
Models
Provided by mboffin.com
15
Getting On Board Ruby On Rails
Controllers

• Handle user requests
• Retrieve data from models
• Invoke methods on models
• Send views and responses to users
• Should contain no business logic
• Only flow control

16
Controllers

• Heres a basic controller action to display a
  blog post
• The URL would be /blog/show/1

17
Getting On Board Ruby On Rails
Views

• The user screens or web pages of your
  applications
• Should contain no business logic
• Should not know about models
• Should contain very little presentation logic
  whenever possible
• Helpers are used for this

18
View

• Views are similar to PHP or ASP pages
• Much more powerful
• Partials can be used to make our work easier

19
Getting On Board Ruby On Rails
Rails-specific MVC components

• Helpers
• Partials
• Layouts

20
Getting On Board Ruby On Rails
Helpers

• Place to put presentation logic
• Available to Views and controllers
• Rails has hundreds of built-in helpers for your
  views
• Easy to make your own

21
Getting On Board Ruby On Rails
Partials

• Pieces of view code that can be reused
• Can be applied to a collection of data!
• Designed to be shared across multiple views
• Examples
• Form fields for Create and Update pages
• Search results
• Tables
• Table rows

22
Getting On Board Ruby On Rails
Layouts

• Your templates are here.
• Global or controller-specific
• No need for header and footer separation
• Rails reads the template last and places your
  application within the content region
• Easy for designers to create layouts without
  knowing Rails

23
Layouts
Your rendered view is inserted here!
24
Getting On Board Ruby On Rails
Migrations

• Database-independent schema definition
• Incrementally define your database
• Makes creation and recreation easy!

Im platform-independent!
25
Getting On Board Ruby On Rails
Scaffolding

• Generation of controllers and views based on
  model definition
• Not meant for production use!
• Needs tweaking first

26
Getting On Board Ruby On Rails
Demo!
27
Getting On Board Ruby On Rails
Scalability

• Rails scales horizontally
• When load is too high, bring up another instance
  of the app load balance your traffic
• Simple solutions for load-balancing
• Apache 2.2 mod_proxy_balance
• Pound
• Pen (Easy but no SSL support)
• Lighttpd mod_proxy

28
Getting On Board Ruby On Rails
Scalability (continued)

• Know your current requirements
• 100 users at the same time isnt a good
  benchmark
• Simultaneous actions dont happen all the time
• Think requests per second
• Measure your existing apps and see how Rails
  compares.
• Your database is often the first scalability
  problem youll encounter in any web application
• Databases can be clustered

29
Getting On Board Ruby On Rails
Performance

• Rails performs on par with other languages
• Slower on Windows
• Limitation of compiled Ruby on Windows
• My tests on similar hardware
• 7 req/sec to 35 req/sec on Windows
• 30 req/second to 150 req/second on Linux
• Increase load by adding more dispatchers and
  load-balancing them

30
Getting On Board Ruby On Rails
Deployment

• Linux is the best for deployment
• Windows is supported
• IIS wont work well, if at all
• Simple workarounds for this exist
• Shared Hosting providers supporting Rails
• Dreamhost (Great for personal stuff)
• BlueHost
• RailsPlayground
• High-availability providers
• RailsMachine
• EngineYard

31
Deployment
32
Getting On Board Ruby On Rails
Security

• Security is a people problem
• Developers must ensure security of their code and
  data
• System admins must keep their systems up to date
• Rails has built-in mechanisms for preventing SQL
  injection and XSS
• Rails is as secure as any other server-side
  language
• How secure is your platform underneath the web
  application?

33
(No Transcript)
34
Choosing a Development Language

• MyDecisionHelper
• Helps you make critical decision using a
  patent-pending decision engine
• Rails application developed by a team of five
• Two Rails programmers, one designer, one
  consultant, and one market analyst, each working
  less than 20 hours per week
• Developers are new to Rails
• One developer made more progress in one weekend
  than in 3 months with .Net!
• What you see didnt exist 2 months ago!

35
Getting On Board Ruby On Rails
Resources - Books

• Learn to Program (Chris Pine)
• Agile Web Development with Rails (Dave Thomas and
  David Heinemeier Hansson)
• Ruby for Rails, Ruby techniques for Rails
  developers (David Black)
• Programming Ruby (Dave Thomas)
• Rails Recipes (Chad Fowler)

36
Getting On Board Ruby On Rails
Resources Web Sites

• www.rubyonrails.org
• wiki.rubyonrails.com
• api.rubyonrails.org
• www.uwec.edu/webdev/ror for additional resources

37
Getting On Board Ruby On Rails
Resources Mailing List

• groups.google.com/group/rubyonrails-talk

38
Getting On Board Ruby On Rails
Resources - Other

• rubyonrails on irc.freenode.org
• Email Brian any time
• hoganbp_at_uwec.edu
• bphogan_at_gmail.com
• Contact Brian any time after the presentation

39
Getting On Board Ruby On Rails
Thanks for coming!
40
Getting On Board Ruby on Rails
Lillian Hillis hillislf_at_uwec.edu

• Brian Hogan
• hoganbp_at_uwec.edu