Transcript Document
Ruby on Rails
8th February 2007 Bill Malkin
Ruby on Rails
Why does RoR interest us?
• Learn “new” concepts and terms.
• Look at “new” architecture.
• Find out what is good and what is dubious.
• May well come across RoR or a Rails-like framework in near future.
• May want to learn an object-oriented language relatively painlessly.
• RoR is easy to install, learn and use. You might want to try it out for yourself!
Bill Malkin 8th February 2007
Ruby on Rails
Executive Summary
• A lot of hype (many evangelists) • Some dubious claims • Some very good, new concepts • Some old concepts with new names • Ruby camp - humble • Rails camp - arrogant • Still missing some essential tools • Rails techniques can certainly be applied elsewhere • Surprisingly large tools and software base • But Ruby and Rails are each very powerful in their own right Bill Malkin 8th February 2007
Ruby on Rails
At First Sight
• Can only be used for web-based, specifically HTML based, applications • Designed for small to medium CRUD-based applications • Cross-platform • Can use same tools and middleware on Windows, Linux and OS X.
• Easy-install packages for Eclipse (with RADRails and Ruby editor plugins), MySQL, Apache, and other Eclipse plugins, eg Subversion.
Bill Malkin 8th February 2007
Ruby on Rails
Books
• •
Beyond Java
- Bruce Tate (evangelist)
Programming Ruby (The Pragmatic Programmers’ Guide)
- Dave Thomas •
Ruby Cookbook
- Carlson & Richardson
Agile Web Development with Rails (Pragmatic Programmers)
Clark - Thomas, Hansson, Breedt and •
Rails Recipes
- Chad Fowler
Ruby on Rails (Up and Running)
[160 pages] - Tate & Gibbs Bill Malkin 8th February 2007
Ruby on Rails
Other References
• Ruby home page http://www.ruby-lang.org/en/ • Ruby Central http://www.rubycentral.com/ • Rails home page http://www.rubyonrails.org/ • Wikipedia entries on Ruby and Ruby on Rails Bill Malkin 8th February 2007
Ruby on Rails
Available Information
8th February 2007 Bill Malkin
Ruby on Rails
History of Ruby
• 1993, Feb 24: Yukihiro Matsumoto ("Matz") started work on Ruby • 1993, Summer: First "Hello, world!" program • 1995, December: First release 0.95
• 1996, December: 1.0 is released • 1999: Supposedly overtakes Python in Japan • 2000: The first official newsgroup • 2000-2001: Several books published • 2003, August 4: 1.8.0 is released Bill Malkin 8th February 2007
Ruby on Rails
History of Rails
• Developed by David Heinemeier Hansson as part of an application called Basecamp.
• 2004, July: Released the framework as open source • 2005, Feb: Shared the commit rights • 2005, Dec: Version 1.0 released • 2006, Mar: Version 1.1 released • 2007, Jan: Version 1.2 released Bill Malkin 8th February 2007
Ruby on Rails
A Ruby Example
class Account attr_reader :balance protected :balance def initialize(balance) #accessor end @balance = balance def greater_balance_than(other) end return @balance > other.balance
end Bill Malkin 8th February 2007
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Ruby on Rails
8th February 2007 Bill Malkin
Ruby on Rails
Basics
• Ruby - fully object oriented • Rails - full stack framework (sort of) • ActionView, ActionController, ActiveRecord • AJAX using script.aculo.us JavaScript libraries • Uses rake (like make or Ant) • Can use an interpreter to try out Ruby commands Bill Malkin 8th February 2007
Ruby on Rails
8th February 2007 Bill Malkin
Ruby on Rails
Terms and Concepts
• Duck Typing • DRY (Don’t Repeat Yourself) • MVC (Model-View-Controller) • Model2 - stateless web apps • Metaprogramming • Convention Over Configuration • Scaffolding 8th February 2007 Bill Malkin
Ruby on Rails
Deployment Environments
• Development, Test and Production • Each has its own, default runtime settings • One database for each • Schema Migrations – Manages the schemas and any changes – Keeps track of a list of migrations – Each migration has version number – Can modify schema without losing data – Can migrate schema through test and production – Can make or undo the schema change Bill Malkin 8th February 2007
Ruby on Rails
Automated Testing
• RoR generates default test cases to test each method in each class • Uses assertions to test results against expected values • Test data refreshed on start of test • Fixtures - contain your test data • Unit Tests - for testing models • Functional Tests - for testing controllers • Integration Tests - for higher level scenarios • Functional and Integration Tests check Http responses • ZenTest and Selenium Bill Malkin 8th February 2007
Ruby on Rails
Configuration
• Uses Convention over Configuration, and Reflection • Therefore very little configuration compared to other frameworks • ActiveRecord configuration can use SQL • Uses YAML (easy to read) rather than XML development: adapter: oci host: 192.168.0.50/examplesid username: exampleuser password: examplepass Bill Malkin 8th February 2007
Ruby on Rails
Web 2.0 Features
from wikipedia • Rich Internet application techniques, optionally Ajax based • CSS • XHTML markup and Microformats • RSS/Atom • Clean and meaningful URLs • Folksonomies (in the form of tags or tagclouds for example) • Wikis, Weblogs, Mashups • REST or XML Webservice APIs Bill Malkin 8th February 2007
Ruby on Rails
Other Rails-Like Frameworks
• Groovy: Groovy on Rails -> Grails • Java: Trails • PHP: PHP on Rails -> PHP on TRAX • ASP.NET: Monorail (Beta 4) • Python: TurboGears (well, sort of) This is another language/framework to watch out for.
Bill Malkin 8th February 2007
Ruby on Rails
Disadvantages
• No big corporate backer • Very few expert Ruby programmers, and universities and TAFEs have not picked it up • Runs slowly (Java ~ 5 times faster but Ruby may be improved by new VM - YARV) • Poor editor support and very slow debugger • No clustering, failover • No two-phase commit • Does not support compound primary keys • Internationalization support is weak • No off-the-shelf reporting tool Bill Malkin 8th February 2007
Ruby on Rails
Advantages
• Standard directory structure for source • Can build prototype very quickly • Can add to and change prototype easily • Can generate scaffolding, if app is more complex, and build on this • Very powerful, high-level commands • Ruby has great short-hand code for common patterns, eg the Value Object • Built in testing, migration, and some version control • Does not constrain the programmer like other frameworks Bill Malkin 8th February 2007
Ruby on Rails
Positive Signs
• • Ruby declared TIOBE's Programming Language of the Year, 2006 (10th)
Agile Web Development with Rails
No 3 in Amazon’s Best Books (Computers and Internet) 2006 • JRuby - Ruby on JVM, being developed by SUN • Mac OS X 10.5 (Leopard) will have Ruby and RoR pre-installed • IBM offers a
Starter Toolkit for DB2 on Rails
• Oracle have tutorials and a FAQ on RoR Bill Malkin 8th February 2007
Ruby on Rails
Defections from Java to Ruby
• James Duncan Davidson (ANT) • Mike Clark (Pragmatic Automation) • Jason Hunter (Java Servlet Programming) • Bruce Tate (Bitter Java, Spring Dev Notebook) • Dion Almaer (Founder of theserverside.com) • Stuart Holloway (Component Dev for Java) • Justin Gehtland (Better, Faster, Lighter Java) • Glenn Vanderburg (Tricks of the Java Programming Gurus) • David Geary (Graphic Java, Core JSF) Bill Malkin 8th February 2007
Ruby on Rails
Trivia
• Ruby was named after the birthstone of a colleague of Matz (birthstone of July) • Pearl (Perl) is the birthstone of June 8th February 2007 Bill Malkin
Ruby on Rails
RoR in Baby Steps
1. Read the Wikipedia entries on Ruby and Ruby on Rails 2. Read the Ruby / Ruby on Rails Cheat Sheet http://www.blainekendall.com/uploads/RubyOnRails Cheatsheet-BlaineKendall.pdf
3. Follow instructions to install tools and web server http://ruby.meetup.com/73/boards/view/viewthread?t
hread=2203432 4. Read the book to develop your first app!
Ruby on Rails, Up and Running
Bill Malkin 8th February 2007
Ruby on Rails
Conclusions
• Can only be used for web-based, specifically HTML-based, applications • Designed for small to medium CRUD-based applications • Cross-platform • A lot of hype (many evangelists) • Some dubious claims, very little expertise • Some very good, new concepts, some old with new names • Still missing some essential tools • Rails-type framework can certainly be applied elsewhere • Surprisingly large tools and software base • Ruby and Rails are each very powerful in their own right • Looks good!
Bill Malkin 8th February 2007