Ruby & Ruby on Rails

Jos de LeonK-LUG July 13, 2006

About Me

Jos de Leon

Career software developer, Problem-Solver by nature

Obsessed with Finding the best way or best approach

Good storyteller

Interests:

Object-oriented development

User-experience, including developers

Best practices - what's worked well for others

Outside: pro basketball/sports, comics

Email: jose_de_leon@hotmail.com

About This Talk

History of Ruby & Rails

About Ruby

About Software Best Practices

How Rails Embodies Best Practices

Demos

RailsConf 2006

History of Ruby on Rails

History of Ruby

History of Rails

History of Ruby

Created by Yukihiro Matz Matsumoto in Japan, 1995

Inspired by Perl, LISP, and Smalltalk

Gained popularity outside Japan around 2000, when Programming Ruby (1st ed) was published by Thomas and Hunt

History of Rails

Conception of David Heinemeier-Hansson

Based on work derived from Basecamp, a web-based project-management application

Extracted as a distinct framework, Summer 2004

1.0 release in December 2005

Rails is a full-stack framework for developing database-backed web applications according to the Model-View-Control pattern.

About Ruby

Understanding Rails requires understanding Ruby

Ruby is a multi-paradigm, interpreted programming language:

Imperative

Object-oriented

Functional

Familiarity with Perl, Smalltalk, Java, LISP, C++ will be an asset

About Ruby

Strong text-processing and regular-expression capabilities on a par with Perl

O-O/functional properties of Ruby allow you to write programs in as natural a language as spoken language

Ruby programs tend to be readable

Ruby has strong collections facilities

Ruby is a scripting-language

Programs can be developed in an incremental, interactive style with fast turnaround

About Best Practices

Best thing about Rails: Embodies and enforces best practices and strong principles in designing software

Frameworks Are Extractions

Rails is based on a successful web-based application, Basecamp

Consistently repeated motifs and patterns: extracted to create the basis for a framework

Drawn from real-life usage and experience

Opposes Big Design Up-Front (BDUF) approach to framework building

BDUF often leads to many libraries that few find useful

Active Record Pattern

Maps rows in a database to objects in an application

Database fields are mapped to object attributes

Add smart operations for an object to interact with a database

4 basic operations:

CREATE (INSERT)

RETRIEVE (SELECT)

UPDATE (UPDATE)

DESTROY (DELETE)

Model-Controller-View

Separation of:

Data (Model)

Operations on Data (Controller):

Data manipulation

Data presentation

Presentation of Data (View)

Test-Driven Development

Rails encourages you to write your tests as you develop

Create tests exercising one facet of your application:

Unit Tests: Essential operations on a single model

Functional Tests: Essential operations between a controller and model

Integration Tests: Interactions between several controllers and models (referring to Use-Cases)

Other Best Practices

Emphasize Simplicity:

Principle Of Least-Surprise (POLS) AKA Law Of Least Astonishment (LOLA)

Do the simplest thing that could possibly work

Enable Refactoring

Don't Repeat Yourself (DRY)

Convention Over Configuration

Handle most common cases most easily, often by default

How Rails Embodies Best Practices

Demo: Simple contact list

Strong application structure created for you

Ruby code is used at every level of development in the Rails framework:

DB creation and schema management (Migrations)

Build maintenance (Rake Tasks)

URL routing (Routes)

Content serving (Webrick, Mongrel)

How Rails Embodies Best Practices

Rails presents a ready-to-use MCV architecture:

Model: ActiveRecord

Controller: ActionController

View: ActionView

ActionController includes controller equivalents (user actions) for ActiveRecord CRUD operations

ActionView can generate output for different media thru Ruby code:

RHTML: Plain text/html

RXML: XML, for Web Services (ActionWebService)

RJS: Javascript for AJAX

Other Rails Features

Rails supports sub-frameworks for:

Testing

AJAX (several popular Javascript libraries are included)

Web services

Email (ActionMailer)

Rails Applications

RadiantCMS

Blogging Engines:

Typo

Instiki (Wiki engine)

E-Commerce Tools:

RightCart (embedded shopping cart)

Shopify (hosted on-line stores)

Rails vs Other Frameworks

Rails (and others) are a reflection of Agile Development techniques

Favored over bloated Enterprise solutions (JEE)

Covers sweet spot of web applications: web front-ends for a database

Rails competes with other frameworks:

Python: Django, TurboGears

Java: JEE stack, HSE, Trails, Grails

PHP, .NET

Rails vs Other Frameworks

TurboGears and Java frameworks: combinations of existing products/projects:

SQLObject (model) CherryPy (view/controller) for TurboGears

Mix of Hibernate/iBatis/Spring (model/controller) Tapestry/Echo2/Spring MVC (view) etc. for Java/JEE

Django very close in philosophy of design with Rails

Agile techniques and practices worked into other technology stacks (.NET)

Ruby as a language has a lot going for it

Demo

Garage Invoicing Application

Componentized approach

Techniques for chaining views and models

A little AJAX

Productivity gains, especially over Java

C/C++

Java/JEE

Ruby/Rails

RailsConf 2006

Application Deployment: Capistrano

Enhanced Scaffolding (AJAX): Streamlined

Generalizing CRUD Beyond Models: ActiveResource

Streamlined

Scaffolding on Steroids

Quickly generate an AJAX interface, deriving relations from ActiveRecord Model specifications

ActiveResource

CRUD Operations can be applied to any resource, not just databases

"What if the whole world could be modeled under the constraints of CRUD?"

Extend CRUD to form basis of Resource-Oriented Architecture (objects that provide CRUD Services)

Finding Out More

Ruby Language: http://www.ruby-lang.org

Ruby On Rails: http://www.rubyonrails.org

Pragmatic Programmers: http://www.pragmaticprogrammer.com

Martin Fowler: http://www.martinfowler.com

DHH: http://www.loudthinking.com

37Signals: http://www.37signals.com

Streamlined: http://streamlined.relevancellc.com

Finding Out More

Other resources:

http://www.ruby-doc.org

http://www.rubyforge.org (Sourceforge for Ruby)

http://www.rubyinside.com

http://www.radiantcms.org

http://www.jadedpixel.com (Shopify, Typo)

Finding Out More

Books (Pragmatic Programmers):

Programming Ruby (2nd Edition) 0974514055

Agile Web Development on Rails (2nd Edition) 097669400X

CRUD Create Retrieve Update DELETE

Database (SQL) INSERT SELECT UPDATE DELETE

HTTP POST GET PUT DELETE

Life Birth Learning Teaching Death

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