Download rails - GEOCITIES.ws

Riding Rails to
Ruby and Riches
Dustin Marx
Bill Jackson
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Presentation Changes Since Printing
• Many slides have been added since hard copy
was printed – these are marked with this image:
• Find latest version of these slides at
http://www.geocities.com/dustinmarx/SW/
• Note that many of these slides have notes and
links to related resources
− See notes in electronic version of presentation
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15 February 2006
RMOUG Training Days 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Agenda
• Introduction to the Ruby Language
• Introduction to the Rails Framework
• Rails AJAX Support
• Active Record
• Rails with Oracle Database
• When Rails Leads to “Riches”
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
What is Ruby?
• Dynamic, Object-oriented Scripting Language
− No primitives – everything is an object
− No globals – simulate with methods on Object
− Mix-ins allow functionality of multiple inheritance
− Supports exception throwing and handling
− Can name methods with operator symbols
− Garbage Collector
• Ruby Has Been Around for Some Time
− 1993 Japan  1995/2000 World
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Basics of Ruby – Variables
• Ruby’s Basic Variable Types
− Instance Variables
• @variableName
− Class Variables
• @@variableName
− Global Variables
• $variableName
− Local Variables
• variableName (begin with lowercase letter or _)
− “Constants”
• VariableName (begin with uppercase letter)
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Basics of Ruby: Control Syntax
“if-then-else”
“switch”
case
if <conditional> then
. . .
. . .
elsif <conditional> then
. . .
else
. . .
end
when <conditional>
. . .
when <conditional>
. . .
else
. . .
end
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Basics of Ruby: Loop Syntax
“while” loop
while <conditional>
. . .
end
Ruby also supports
iterators and provides
the advantages of
iterators.
“do-while” loop
until <conditional>
. . .
end
“for” loop
for <var> in <expr> do
. . .
end
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15 February 2006
RMOUG Training Days 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Basics of Ruby - Syntax
• Methods
− Use def keyword to define methods
− Prefix “class” methods with self.
• “Object” methods have no prefix on name
− Convenience Accessor Methods
• attr_accessor, attr_reader, attr_writer
• Allowed But Not Required
− Semicolons
− Parentheses
− Curly Braces
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Basics of Ruby – Comments
• Single-line comments
− # I am a comment.
− Comment from # to end of line
• Multi-line comments
− =begin
− I am a comment.
− =end
− =begin and =end must begin their respective lines
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15 February 2006
RMOUG Training Days 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Basics of Ruby – Reserved Words
• These are some of Ruby’s Reserved Words
− BEGIN, END, begin, end
− if, else, elsif, case, then
− and, or, not
− false, true
− do, redo, while
− self, super
− nil
− __FILE__, __LINE__
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Conventions of Ruby
• Rails is heavily convention-based, but so is the
language upon which it is based (Ruby)
• Conventional Ruby
− Variables (all types) begin with lowercase letter
• Applies to global ($), instance (@), or class (@@) variables
• Multiple words in name separated by underscore (_)
− Class names and Constants begin with uppercase
letter
• Multiple words separated by each new word starting with
uppercase letter
− Method names treated like variable names (above)
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15 February 2006
RMOUG Training Days 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Basics of Ruby:
Features of Dynamic Scripting Languages
• Extensive regular expression support
• Extensive string manipulation
• Dynamic language features
− Reflection
− Add methods to objects at runtime
− Add data members to objects at runtime
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Ruby Graphical Libraries
• Non-web Graphical Libraries for Ruby
− Tk
− OpenGL
− GTK
− Fox
− QT
− VTK
• No graphical libraries necessary for Rails!
− You only need a standard web browser
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Ruby-Provided Libraries and Tools
• Several of Rails’ strong points are actually
directly or indirectly provided by Ruby
− Core API / Built-in Functions/Library
• http://www.ruby-doc.org/core/
− Ruby Standard Libraries
• http://www.ruby-doc.org/stdlib/
− Ruby Standard Tools
• Debugger, Profiler, irb
− Other Ruby Tools
• Ruby/DBI, Ruby Coverage, Ruby Interactive (ri),
DamageControl, Builder, Distributed Ruby (DRb), REXML
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Select Ruby Core/Standard Libraries
• Benchmark
• Regexp
• Delegator
• Signal
• ERB and ERB::Util
• String
• File
• Test::Unit
• IO
• Thread
• Logger
• URI and URI::xxxxx
• Math
• YAML
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
What is Rails?
• Database-driven Web Framework
• Runs on Ruby
• Open Source – MIT License
• Stresses Convention over Configuration
• Sub-Frameworks
− Active Record
− Action Pack
• Action Controllers
• Action Views
− Action Mailer
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Do We Need Another Web
Framework?
• There are many web frameworks in many different
programming languages:
− Java
• Struts, Tapestry, Velocity, Spring Framework, WebWork, Cocoon,
Mentawai, RIFE, … many more …
− PHP
• PHP on TRAX, php.MVC, AjaxAC, blueshoes, … more …
− Perl
• Maypole, Catalyst, Mind Web, … more …
− Python
• Subway, CherryPy, Django, Zope, Webware for Python, Quixote
− Ruby – Something other than Rails? 
• Nitro
− Oracle-specific Alternatives
• HTML DB, Project Raptor (SQL Developer)
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15 February 2006
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Ruby
Rails
AJAX
Type in URL
Controller can call another
controller method with
redirect_to :action call
Oracle DB Conclusion
.rhtml
View
Template
rendered
as HTML
page
Invoke method
View Template invokes
controller method pointed to by
start_form_tag :action
(form_tag :action) or
link_to :action
AR/ORM
Rende
r new
web
page
Model
<model_name>.rb
extends
ActiveRecord::Base
Controller
<model_name>s_controller.rb
$
Invoke method
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15 February 2006
RMOUG Training Days 2006
The model
classes are
used by
both the
view
templates
and by the
controllers
Controller
renders new
web page
either
through
same-name
implicit
.rhtml or
via render
:action
call
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Oracle DB Conclusion
Convention Over Configuration
• Rails generally favors assumed conventions over
explicit configuration
− Rails uses introspection when developers follow
conventions
• Effects of Emphasis on Convention
− Dramatically reduces configuration files
− Must know Rails’ assumptions/conventions
− Rails most productive if your code and database
schemas can conform to Rails’ conventions
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Ruby
Rails
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AR/ORM
Oracle DB Conclusion
Some Rails Expected Conventions:
Database and ActiveRecord
• Several examples of convention over
configuration in Database/ActiveRecord
− Database table name is plural form of model name
− Database primary key column named ‘id’
− Expected DB sequence for each table
• <table_name>_seq
− DB columns ending with _at and _on treated as
TimeStamp and Date respectively
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15 February 2006
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Rails
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AR/ORM
Oracle DB Conclusion
Some Rails Expected Conventions:
More Database and ActiveRecord
• Several more examples of convention over
configuration in Database/ActiveRecord
− Name foreign key column in table with name of
model upon which it depends followed by “_id”
• Example: If table “programs” has foreign key to table
“networks”, foreign key in “programs” pointing to
“networks” should be named “network_id”
− Join/Intersection table name combines names of two
joined/intersected tables
• Separate the table names with underscore
• Table names being joined appear in alphabetical order
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Additional Rails Expected
Conventions
• Not all Rails conventions are DB/ActiveRecord
− Template (.rhtml) matches calling action method
name
− Layout (.rhtml) matches calling controller
− Directory structure of Rails applications
− Test Files (Unit/Functional/Fixtures)
• See this web page for more details on these Rails
conventions
− http://www.geocities.com/dustinmarx/SW/rails/conventions.html
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15 February 2006
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Oracle DB Conclusion
Rails URL Routing
• Rails handles URL-based requests as specified in
config/routes.rb
• Default setting
− map.connect ‘:controller/:action/:id’
movies_controller.rb class
show() action method
Model/DB Row ID
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15 February 2006
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Ruby
Rails
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AR/ORM
Oracle DB Conclusion
Rails All-Application Functionality:
Make Methods Available to Entire App
• Provide filters/methods to all Controllers
− …\app\controllers\application.rb
− ApplicationController < ActionController::Base
• Provide methods to all View Template helpers
− …\app\helpers\application_helper.rb
− module ApplicationHelper
• Provide functions to all Models
− Place functions in file in lib
− Place reference to file in
config/environment.rb
− Include module in ActiveRecord::Base
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Ruby
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Oracle DB Conclusion
Rails Configuration
• Rails has very little configuration
− Convention/introspection more commonly used
− .yml files rather than .xml files
− database.yml, Test Fixture .yml files, etc.
• database.yml
development:
adapter: oci
host: orcl
username: scott
password: tiger
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AJAX
AR/ORM
Oracle DB Conclusion
RailsRails
Conventional
Directory
Structure
Application Root Level
Ruby
<yourApplicationName>
app
Application’s significant and specific code
components Storage location for Rails components
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config
db
doc
lib
Configuration files (database.yml, etc.)
log
public
script
test
vendor
Storage location for Rails app’s log files
Available to web server
Rails generation and other scripts
Unit/functional tests; fixtures/mocks
Third-party/COTS libraries
Rails documentation (RDoc)
Own, application-specific libraries
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Rails
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Oracle DB Conclusion
Rails Conventional Directory Structure
app, public, and test Sub-Directories
app
controllers
helpers
models
views
public
images
javascripts
stylesheets
test
fixtures
functional
mocks
development
layouts
test
unit
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15 February 2006
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Rails
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AR/ORM
Oracle DB Conclusion
Rails Models: Standard Validations
Rails supports many common validations with the standard
validations below. Override the model’s validate()
method to implement your own custom validation.
•
validates_acceptance_of
•
validates_inclusion_of
•
validates_associated
•
validates_length_of
•
validates_confirmation_of
•
validates_numericality_of
•
validates_each
•
validates_presence_of
•
validates_exclusion_of
•
validates_size_of
•
validates_format_of
•
validates_uniqueness_of
All validations shown in blue are discussed in more
detail in the slide notes.
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15 February 2006
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Rails
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AR/ORM
Oracle DB Conclusion
Rails Controller
• “Controls” flow
− Methods in Controller class are “actions”
− Renders view or redirects to another action
− Actions should end with single render or redirect_to
• The render Possibilities
−
−
−
−
−
Render action
Render partial
Render template
Render file
Render text
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Some Objects of the Controller
• Requests
− request Accessor
• Parameters
− params Hash
• Write/read cookies
− cookies Attribute
• Rails Sessions
− @session Hash
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15 February 2006
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Ruby
Rails
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AR/ORM
Oracle DB Conclusion
Controllers: Filters
• Share before (pre) and after (post) processing
between multiple controllers
• Filter Methods
− after_filter, prepend_after_filter
− before_filter, prepend_before_filter
− around_filter, prepend_around_filter
• Filter Conditions
$
− :only
− :except
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15 February 2006
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Ruby
Rails
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AR/ORM
Oracle DB Conclusion
Rails Template Files – View
• “Ruby/Rails Server Pages”
− Embed Ruby script in HTML with <% and <%= tags
•
•
•
•
Referred to as “Embedded Ruby” (ERb)
Similar to JSP and ASP!
Normally close scriptlet/ERb code with %>
Close ERb code with (hyphen) -%> to ignore white space
− .rhtml files (rather than .html files)
− Use components, partials, and layouts
− Alternative approach is Builder approach
• See later slide
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15 February 2006
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Oracle DB Conclusion
Templates/Controller Connection
• Controller renders similarly named view or …
− :action
− :template
− :file
• View shares access to all of controller’s instance variables
• View shares access to significant objects:
− headers, params, request, response, session
• View’s controller object allows access to all of
controller’s methods
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails Built-in HTML Aids
• html_escape() or h() method
− Escapes HTML characters
• sanitize()
− Escapes HTML tags and JavaScript links that are
most often associated with malicious code
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails Views: Formatting Helpers
• Numerous built-in view helpers for common
view- and format-related functionality
• Small sampling of these built-in view helpers:
− number_to_concurrency()
− number_to_percentage()
− number_with_delimiter()
− number_with_precision()
− markdown()
− textile()
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails Views: More Helpers
• link_to_unless_current
− Render links for all site pages except one currently
displayed
• Pagination for multiple entries
− Controller’s paginate()
− View’s pagination_links()
• Form Helpers
• Field Helpers
− Including file upload support
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails Views and DRY:
Layout, Partials, and Components
• Layouts
− Provide layout/format of web page
− Think Struts’ early template library
• Partials
− Partial templates designed to be used by multiple
pages
• Components
− Shared template/controller functionality
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails Views: Builder Approach
• Templates are not only Rails approach for views
• Use Builder to write XML
− Programmatically build up view
− API produces XML similar to approach PL/SQL
Web Toolkit uses to produce HTML
• Ruby’s dynamic method support required for XML
production
− Method names you specify for builder generally
produce XML tags with same name
• Use tag! in cases of reserved method names
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails – Action Mailer
• Framework/layer supporting outgoing and incoming email services
• Configuring Action Mailer
− …/config/environment.rb
− …/config/environments/
• development.rb, production.rb, and test.rb
• Sending E-mail
− ruby script/generate mailer …
− Mailer is stored in models directory
− E-mail templates stored in views directory
• Receiving E-mail
− Implement receive() method to receive e-mail messages
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails – Web Services
• Rails Action Web Service
− SOAP / XML-RPC
− Create API Definition
• Extend ActionWebService::API::Base
• api_method (:expects and :returns)
− Dispatching ties client requests to Rails implementation
− Not fully compliant with W3C specifications
• Rails and REST
− “REST on Rails”
• http://www.xml.com/pub/a/2005/11/02/rest-on-rails.html
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Ruby
Rails
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AR/ORM
Oracle DB Conclusion
Rails Scaffolding
• Temporary framework to
support construction of
new web application
• Rapidly build simple
web-based CRUD
support
• Can add features and
appearance/presentation
improvements as desired
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See definition of term ‘scaffolding’ at
http://www.answers.com/topic/scaffolding
RMOUG Training Days 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails Built-in Testing Framework
• Extends Ruby’s Test::Unit testing framework
− Think JUnit, utPLSQL, and other “N”-Unit Test Frameworks
• Scripts generate test classes automatically
• Test-specific Database specified in database.yml
• Standard and custom assertions
• Fixtures
• Mock Objects
• A Guide to Testing Rails
− http://manuals.rubyonrails.com/read/book/5
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Ruby
Rails
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Oracle DB Conclusion
More on Rails Built-in Testing
• “Unit” Testing
− Refers to testing of Rails’ model classes
− Fixtures describe initial contents of model
− setup Method
• “Functional” Testing
− Refers to testing of Rails’ controller classes
− setup and teardown Methods
− HTTP Request methods (such as get and post)
− Controller Assertions and Controller Variables
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15 February 2006
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Ruby
Rails
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AR/ORM
Oracle DB Conclusion
Rails/Ruby and rake
• rake: Something like make
− Implemented in Ruby programming language
− http://rake.rubyforge.org/
• Using rake
− rake --tasks
• Show options available with rake
− rake appdoc
• Produces Rails application’s documentation
− rake stats
• Displays lines, LOC, # Classes, # Methods, M/C, LOC/M for
Helpers, Controllers, Components, Models, Unit Tests, and
Libraries
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
AJAX
• AJAX is …
− Asynchronous JavaScript And XML
− Collections of technologies for creating interactive
web applications
• HTML/XHTML/CSS
• XMLHttpRequest
− “de facto” Standard (MSIE, Mozilla Browsers, Safari, Opera)
• Significant Piece of “Web 2.0” / DHTML
− Catchy term for the above combination of
technologies
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
So What’s the Big Deal about AJAX?
• Richer and more dynamic web applications
− Asynchronous means non-blocking
− Small portion of page can update based on server
query without complete reloading of the page
− Change appearance/behavior of portion of web page
• Server can pass XML, HTTP, JavaScript, or other text back
to client
− Hides some of the rigidness of the request/response
model
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15 February 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails: AJAX
• Makes use of Prototype and script.aculo.us
JavaScript libraries
− http://prototype.conio.net/
− http://script.aculo.us/
• Use one of these three options:
− <%= javascript_include_tag :defaults %>
− <%= javascript_include_tag ‘prototype’ %>
− <%= define_javascript_functions %>
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails and AJAX: Key Methods
• link_to_remote
− Link pointing to action to be invoked
• form_remote_tag
− Send entire form’s information to server
• observe_field
− Invoke server action based on certain form element
− observe_form is similar but for entire form
• periodically_call_remote
− Periodically invoke server action
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails ORM: Active Record
• Active Record
− Rails Object-Relational Mapping
− Based on Martin Fowler’s Active Record architecture
pattern
− Uses Single Table Inheritance ORM Approach
− Makes heavy use of database schema conventions
• Can override most of these in Ruby classes
− Built-in support for standard CRUD operations
• No SQL needed – even very little Ruby code required
− Allows for customized SQL
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Oracle DB Conclusion
Rails: Models and Tables – 1:1
person.rb
address.rb
class Person < ActiveRecord::Base
has_one :address
end
class Address < ActiveRecord::Base
belongs_to :person
end
Oracle Database
People
id
…
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Addresses
person_id
…
One address per person and one person per address.
RMOUG Training Days 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails: Models and Tables – 1:M
person.rb
address.rb
class Person < ActiveRecord::Base
has_many :addresses
end
class Address < ActiveRecord::Base
belongs_to :person
end
Oracle Database
People
id
…
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15 February 2006
Addresses
person_id
…
Each person may have more than one address, but
there is only one person at a particular address.
RMOUG Training Days 2006
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails: Models and Tables – M:N
person.rb
address.rb
class Person < ActiveRecord::Base
has_and_belongs_to_many :addresses
end
class Address < ActiveRecord::Base
has_and_belongs_to_many :people
end
Oracle Database
People
id
…
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15 February 2006
Addresses_People
address_id
person_id
Addresses
id
…
Many people may live at a particular address and
a person may have many addresses.
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Ruby
Rails
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AR/ORM
Oracle DB Conclusion
Rails and ActiveRecord:
SQL Flexibility
• Finder Methods
− find (set your WHERE :conditions)
− find_by_sql (specify entire SQL select)
• Module
ActiveRecord::ConnectionAdapter
s::DatabaseStatements.rb
− execute(), insert(), update(), delete()
− select_all(), select_one(), select_value(), select_values()
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
ActiveRecord Transactions
• ActiveRecord supports ACID transactions
• Examples
ModelClass.transaction do
. . .
model/DB operations
. . .
end
ModelClass.transaction
(ObjectA, ObjectB) do
. . .
model/DB operations
. . .
end
DB-only
Transaction
DB and Objects
Transaction
• Distributed two-phase transactions NOT
supported
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15 February 2006
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Ruby
Rails
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AR/ORM
Oracle DB Conclusion
Database “Limitations” of
Rails/ActiveRecord Approach
• No standard support for stored procedures
− Not the “Rails way”
• Requires single column primary key
− Integer column named ‘id’
− No composite keys allowed
• Rails Assumptions can make some DB features ‘more
tricky’ to use in the Rails applications
− No triggers or constraints (including referential integrity)
considered in ActiveRecord conventions
• Lacks distributed two-phase commit support
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails and the Oracle Database
• Rails is typically presented in conjunction with
MySQL database
− But can support any database with Ruby adapter
• Oracle OCI8 adapter for Ruby is available
− http://rubyforge.org/projects/ruby-oci8/
• Rails support for Oracle doesn’t seem (at least to
me) to be as robust as that for MySQL
− Many features of Rails are supported on Oracle DB
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle
1.
Download RubyGems
2.
Install Rails with RubyGems
3.
Create structure for new Rails web application
4.
Run Web Server
5.
Modify database.yml file for Oracle DB
6.
Ensure Availability of Ruby/Oracle interface
7.
Verify OCI client library in appropriate path
8.
Create model and controller classes in Ruby
9.
Employ Rails Scaffolding
10.
Create necessary database sequences
11.
Ensure column (preferably primary key) is named ID
Single Step
Possible
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#1: Download RubyGems
•
RubyGems is packaging and distribution
format for Ruby libraries and applications
•
Access download and the instructions at
http://download.rubyonrails.com/
•
RubyGems Manuals
− http://docs.rubygems.org/
− http://docs.rubygems.org/read/chapter/3
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#2: Install Rails with RubyGems
• gem install rails --includedependencies
• Ensure that Ruby executable is correctly included
in path
− I had to add \bin (for c:\ruby\bin) and place
semicolon to separate entries
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#3: Create Structure for New Rails App
• Rails will create necessary directory structure and
key files for your new application
− Syntax: rails /<<directories>>/<app_dir>
− Example: rails /rmoug/td2006/simpleapp
• Creates (among other things):
− Folders for application’s controllers, models, and
views
− Scripts for running Rails and the application on Rails
− Configuration and environment support
− Test support directories and files
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#4: Running the Web Server
• WEBrick Web Server comes with Rails
• RunWEBrick with this command from newly created
Rails application directory:
− ruby script/server
• Verify successful web server start with URL:
− Syntax: http://<IP_Address>:<port>/
− Example: http://127.0.0.1:3000/
• IP address is of machine on which server is run and likely will
differ from that shown above
• Port may differ (default is 3000)
− Use –p or --port for different port
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ruby script/server --help displays help
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#5: Modify database.yml File
• database.yml file located in new Rails
application’s config directory
• Default database specified in this file is MySQL
• Set file similarly to that shown below:
Default database.yml for MySQL
development:
adapter: mysql
database: rails_development
host: localhost
username: root
password:
$
database.yml for Oracle
development:
adapter: oci
host: orcl
username: scott
password: tiger
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#6: Access Ruby/Oracle Interface
• Ruby/OCI8
− Ruby interface for Oracle using OCI8
− Download relatively small file with Ruby code
− Run this downloaded Ruby script with Ruby
executable
− http://rubyforge.org/projects/ruby-oci8/
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#7: OCI Client Library
• Ensure that OCI client library is in appropriate
location:
− Windows
• Directory with oci.dll added to PATH environment
variable
− Unix/Linux
• Directory with libclntsh.so added to
LD_LIBRARY_PATH
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#8: Create Model and Controller
• Use Rails scripts to create model and controller
classes in Ruby language
− Model
• ruby script/generate model <model_class>
− Controller
• ruby script/generate controller <model_class>
− Examples
• ruby script/generate model dvd
• ruby script/generate controller dvd
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#9: Employ Rails Scaffolding
• Rails Scaffolding does the heavy lifting for you!
− Though the view leaves something to be desired
• Automatically supports CRUD operations for models Create
and database tables meeting Rails conventions
Read
− Model and database tables mapped together by names
• Table name plural version of singular model name
Update
Delete
− Appropriate sequences exist
− Tables have column called ‘ID’
• Employ Rails scaffolding with single Ruby statement in
controller class:
$
− scaffold :<model_class>
− Example: scaffold :dvd
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
Combine Steps #8 and #9
• Now can perform steps #8 and #9 all at once:
− ruby script/generate scaffold <model_class>
•
This single statement does all of the following:
− Creates Model
• Same as
ruby script/generate model <model_class>
− Creates Controller
• Same as
ruby script/generate controller <model_class>
− Creates Scaffold and Views
• Similar to adding scaffold: <model_class> in controller
• Advantage: Can inspect scaffold/view code with newer approach
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#10: Add Necessary DB Sequences
• Need to create sequences in Oracle database
− This is another Rails-expected convention
− Through Rails 0.13…
• CREATE SEQUENCE rails_sequence;
− After Rails 0.13…
• CREATE SEQUENCE <tablename>_seq;
− (for each table)
• See Rails Ticket #1798
− http://dev.rubyonrails.org/ticket/1798
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Starting with Rails and Oracle:
#11: Name Column ‘ID’
• Name at least one column, preferably the
primary key, of table(s) with name ‘ID’
− Another Rails convention
− Can be overridden with set_primary_key in
Ruby model class
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
The Rails to Riches:
Application Characteristics
• Rails Is Best For:
− Prototypes
− Web-only or Web-dominant applications
− Web-based database access tools
• Rails is Not As Preferable When:
− Application is not web-based
− Developers have little control over fairly complex
database and database conventions
• Legacy database systems often fit into this category
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
The Rails to Riches:
Organizational Characteristics
Organization/Personnel Skills/Preferences Play Role in Success with Rails
Traits Favoring Use of Rails
Traits Favoring Rails Alternatives
Prefer agile development
Prefer traditional development
Prefer open source
Prefer commercial products/support
Prefer dynamic languages
Prefer statically typed languages
Prefer “bleeding edge”
Prefer time-tested / proven
Prefer/Enforce naming conventions
Prefer/Enforce configuration
Common coupled SW/DB control
No common SW/DB control
Prefer Simple DB Features
Prefer rich/complex DB Features
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Ruby
Rails
AJAX
AR/ORM
Oracle DB Conclusion
Rails and the Future
• Rails’ popularity is rapidly growing
− Expect it to continue to grow in future
• Rails (hopefully) will impact web development
− J2EE/.NET can adopt some ideas from Rails
− Rails can provide J2EE/.NET developers with own
inspiration
• Biggest threat to Rails’ success
− The ‘Next Rails’ (do we know what that will be?)
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APPENDIX
Riding Rails to Ruby
and Riches
Background Materials and
Supplemental Slides
$
$
Please see the 24-page
white paper associated
with this presentation
for an extensive list of
references and
resources related to
Ruby on Rails.
APPENDIX: Acronyms
Acronyms
• CRUD – Create, Retrieve, Update, Delete
• DIY – Do It Yourself
• DRY – Don’t Repeat Yourself
• ERb – Embedded Ruby
• LAMP – Linux, Apache, MySQL, Perl/PHP/Python
• MVC – Model-View-Controller
• POLS – Principle of Least Surprise
• RoR – Ruby on Rails
• YAML – YAML Ain’t Markup Language
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APPENDIX: References and Resources
Riding Rails to Ruby and Riches:
References and Resources
• The following set of slides contain links to
online articles that describe different aspects of
Rails
− See associated white paper for another set of
references and resources
− See notes for individual slides in this presentation for
relevant online references
− These links are good for exposure to Rails
• For thorough background on Rails, see book:
$
− Agile Web Development with Rails
$
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APPENDIX: References and Resources
References and Resources:
Ruby on Rails How-Tos/Licenses
• Rails Documentation
− http://documentation.rubyonrails.com/
• Howtos Database in Rails Wiki
− http://wiki.rubyonrails.com/rails/show/HowtosDatabase
• Howtos File Access in Rails Wiki
− http://wiki.rubyonrails.com/rails/show/HowtosFiles
• MIT License
− http://www.opensource.org/licenses/mit-license.php
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APPENDIX: References and Resources
References and Resources:
Curt Hibbs on Ruby on Rails
• Rolling With Ruby on Rails, Part 1
− http://www.onlamp.com/pub/a/onlamp/2005/01/20/rails.html
• Rolling With Ruby on Rails, Part 2
− http://www.onlamp.com/pub/a/onlamp/2005/03/03/rails.html
• What is Ruby on Rails
− http://www.onlamp.com/pub/a/onlamp/2005/10/13/what_is_rai
ls.html
• AJAX on Rails
$
− http://www.onlamp.com/pub/a/onlamp/2005/06/09/rails_ajax.ht
ml
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APPENDIX: References and Resources
References and Resources:
More on Rails
• Ruby on Rails in the Enterprise Toolbox
− http://www.javaranch.com/journal/200601/rails.htm
l
• Ruby on Rails E-mail Forum
− http://www.ruby-forum.com/forum/3
• Ruby on Rails Newcomers FAQ
− http://www.railsfaq.org/
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APPENDIX: References and Resources
References and Resources:
Rails API Documentation
• Ruby on Rails Edge Documentation: Files
− http://railsmanual.org/doc/list?type=files
• Ruby on Rails Edge Documentation: Classes
− http://railsmanual.org/doc/list?type=classes
• Ruby on Rails Edge Documentation: Methods
− http://railsmanual.org/doc/list?type=methods
• Rails Manual: ActiveRecord
− http://railsmanual.org/class/ActiveRecord::Base
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APPENDIX: References and Resources
References and Resources:
Rails Deployment
• This topic was not covered in the presentation,
but is very important
− Real Lessons for Rails Deployment
• http://duncandavidson.com/essay/2005/12/railsdeployme
nt
− Deploying Rails with Apache 2
• http://duncandavidson.com/essay/2006/01/railsonapache
− Deploying Rails with LightTPD
• http://duncandavidson.com/essay/2005/12/railsonlighty
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APPENDIX: References and Resources
References and Resources: Ruby
• Programming Ruby: The Pragmatic Programmer’s Guide
− http://whytheluckystiff.net/ruby/pickaxe/
• The Ruby Programming Language
− http://www.informit.com/articles/article.asp?p=18225
• Why’s (poignant) guide to Ruby
− http://poignantguide.net/ruby/
• Ruby off the Rails
− http://www-128.ibm.com/developerworks/library/jruby/?ca=dgr-lnxw01RubyOffRails
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APPENDIX: Cheat Sheets
References and Resources:
Rails-Related Cheat Sheets
• Ruby on Rails – A Cheat Sheet (Blaine Kendall)
− http://www.blainekendall.com/uploads/RubyOnRails-CheatsheetBlaineKendall.pdf
• What Goes Where (Amy Hoy)
− http://www.slash7.com/cheats/rails_files_cheatsheet.pdf
• ActiveRecord Relationships (Amy Hoy)
− http://www.slash7.com/cheats/activerecord_cheatsheet.pdf
• Form Helpers (Amy Hoy)
− http://www.slash7.com/cheats/form_helpers.pdf
• What’s Ajax? (Amy Hoy)
− http://www.slash7.com/cheats/whats_ajax_cheatsheet.pdf
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APPENDIX: Cheat Sheets
References and Resources:
More Rails-Related Cheat Sheets
• Ruby on Rails Cheat Sheet
− http://www.ilovejackdaniels.com/ruby-on-rails/ruby-on-railscheat-sheet/
• Rails Migration Cheat Sheet
− http://garrettsnider.backpackit.com/pub/367902
• JavaScript Cheat Sheet
− http://www.ilovejackdaniels.com/javascript/javascript-cheatsheet/
• CSS Cheat Sheet
− http://www.ilovejackdaniels.com/css/css-cheat-sheet/
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APPENDIX: Q&A
Is Rails Only Hype?
• No.
• There are many substantial and innovative
features of Rails. These include scaffolding,
built-in Ajax support, simple object-relational
mapping (ORM), and convenient MVC support.
• Enthusiasm in Rails will likely lead to
enhancements in these and other areas.
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APPENDIX: Q&A
Will Rails Replace Java / .NET?
• In some niche areas – DB-driven web apps
• Rails addresses some aspects of web development
commonly implemented in Java/J2EE or .NET, but it
does not readily and completely replace all of the
enterprise functionality these frameworks provide. For
example, not everything is web-based!
• Rails will likely be used in some parts of applications
along with J2EE, .NET, and other technologies. SOA
makes this even more likely.
• C/C++, Java, .NET, Perl, PHP, Python, etc. are not
going away
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APPENDIX: Q&A
Is Rails Just the Flavor of the Month?
• Time will tell for certain, but I think it is more
than the “flavor of the month”
• Rails offers enough innovative features that it
will likely continue to have success similar to
other technologies that were once the “hottest”
thing around and are still widely used:
− Java / J2EE, .NET, Python
− Spring Framework
− Struts
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APPENDIX: Q&A
What is the Best Thing About Rails?
• Depends who you ask:
− Built-in Ajax support
− ActiveRecord ORM
− Scaffolding
− Tightly integrated stack
− Not having to compile
− No license cost
− Encouragement of best practices
− Convention over configuration
− Many common “web things” made simple
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APPENDIX: Q&A
What’s the Best Way to Learn Rails?
• Introducing Self to Rails / Curiosity
− Paper associated with this presentation
− Curt Hibbs’ articles listed on previous slide
• Possibly consider Rails for web development
− Read links in this presentation and paper, especially in areas of
Rails that most appeal to you
• Likely to use Rails for significant web development
− Read book Agile Web Development with Ruby on Rails
• SoftPro has copies of this book for sale in conference’s Exhibition
Hall
− Additional books to be available soon
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