Ruby on Rails 3 Tutorial

571 Pages·2010·8.98 MB·English

by  Michael Hartl

www.it-ebooks.info
Praise for Ruby on Rails™ 3
Tutorial
RailsTutorial.org: Michael Hartl’sawesome new
Rails Tutorial
TheRubyonRails™3Tutorial:LearnRailsbyExamplebyMichaelHartlhasbecomea
mustreadfordeveloperslearninghowtobuildRailsapps.
—PeterCooper,editorofRubyInside
Very detailed and hands-on Rails Tutorial!
Greatjob!I’mlearningRails,andfoundyourtutorialtobeoneofthemostdetailedand
hands-on guides. Besides many details of Rails, it also taught me about Git, Heroku,
RSpec, Webrat, and most important (at least to me), it emphasized the Test-Driven
Development(TDD)methodology.Ilearnedalotfromyourtutorial.
Keepupthegoodjob!Thankssomuchforsharingit.
—AlbertLiu,seniormanager,AchievoCorporation.
Ruby on Rails Tutorial is the best!
JustwantedtosaythatyourRubyonRailstutorialisthebest!
I’vebeentryingforawhiletowrapmyheadaroundRails.Goingthroughyourtutorial,
I’m finally feeling comfortable in the Rails environment. Your pedagogical style of
www.it-ebooks.info
graduallyintroducingmorecomplextopicswhileatthesametimegivingthereaderthe
instantgratificationandasenseofaccomplishmentwithworkingexamplesreallyworks
for me. I also like the tips and suggestions that give me a sense of learning from a real
Railsinsider.Youre-mailresponsetoaproblemIranintoisanexampleofyourgenerous
sharingofyourexperience.
—RonBingham,CEO,SounDBuytz
I love the writing style of the Rails Tutorial
IlovethewritingstyleoftheRailsTutorial,andthereissomuchcontentthatisdifferent
fromotherRailsbooksoutthere,makingitthatmuchmorevaluable...Thanksforyour
work!
—AllenDing
www.it-ebooks.info
RUBY ONRAILS™ 3TUTORIAL
www.it-ebooks.info
Addison-Wesley
f i l i
Pro ess ona Ruby Ser es
Obie Fernandez, Series Editor
Visit informit.com/ruby for a complete list of available products.
The Addison-Wesley Professional Ruby Series provides readers
with practical, people-oriented, and in-depth information about
applying the Ruby platform to create dynamic technology solutions.
The series is based on the premise that the need for expert reference
books, written by experienced practitioners, will never be satisfied solely
by blogs and the Internet.
www.it-ebooks.info
RUBY ONRAILS™ 3TUTORIAL
Learn Rails™ by Example
Michael Hartl
UpperSaddleRiver,NJ•Boston•Indianapolis•SanFrancisco
NewYork•Toronto•Montreal•London•Munich•Paris•Madrid
Capetown•Sydney•Tokyo•Singapore•MexicoCity
www.it-ebooks.info
Manyofthedesignationsusedbymanufacturersandsellerstodistinguishtheirproductsareclaimed Editor-in-Chief
MarkTaub
astrademarks.Wherethosedesignationsappearinthisbook,andthepublisherwasawareofa
trademarkclaim,thedesignationshavebeenprintedwithinitialcapitallettersorinallcapitals. ExecutiveAcquisitionsEditor
DebraWilliamsCauley
Theauthorandpublisherhavetakencareinthepreparationofthisbook,butmakenoexpressedor
impliedwarrantyofanykindandassumenoresponsibilityforerrorsoromissions.Noliabilityis ManagingEditor
assumedforincidentalorconsequentialdamagesinconnectionwithorarisingoutoftheuseofthe JohnFuller
informationorprogramscontainedherein. ProjectEditor
ElizabethRyan
Thepublisheroffersexcellentdiscountsonthisbookwhenorderedinquantityforbulkpurchasesor
specialsales,whichmayincludeelectronicversionsand/orcustomcoversandcontentparticularto CopyEditor
yourbusiness,traininggoals,marketingfocus,andbrandinginterests.Formoreinformation,please EricaOrloff
contact: Indexer
ClaireSplan
U.S.CorporateandGovernmentSales
[phone] Proofreader
[email protected] ClaireSplan
ForsalesoutsidetheUnitedStatespleasecontact: PublishingCoordinator
KimBoedigheimer
InternationalSales
[email protected] CoverDesigner
GaryAdair
VisitusontheWeb:informit.com/aw
Compositor
LibraryofCongressCataloging-in-PublicationData GlyphInternational
Hartl,Michael.
Rubyonrails3tutorial:learnRailsbyexample/MichaelHartl.
p. cm.
Includesindex.
ISBN-10:0-321-74312-1(pbk.:alk.paper)
ISBN-13:978-0-321-74312-1(pbk.:alk.paper)
1.Rubyonrails(Electronicresource)2.Websitedevelopment.3.Ruby
(Computerprogramlanguage)I.Title.
TK5105.8885.R83H372011
(cid:2)
005.117–dc22 2010039450
Copyright©2011MichaelHartl
Allrightsreserved.PrintedintheUnitedStatesofAmerica.Thispublicationisprotectedby
copyright,andpermissionmustbeobtainedfromthepublisherpriortoanyprohibitedreproduction,
storageinaretrievalsystem,ortransmissioninanyformorbyanymeans,electronic,mechanical,
photocopying,recording,orlikewise.Forinformationregardingpermissions,writeto:
PearsonEducation,Inc.
RightsandContractsDepartment
501BoylstonStreet,Suite900
Boston,MA02116
Fax:[phone]
ThesourcecodeinRubyonRails™3TutorialisreleasedundertheMITLicense.
ISBN13:978-0-321-74312-1
ISBN10: 0-321-74312-1
TextprintedintheUnitedStatesonrecycledpaperatEdwardsBrothersinAnnArbor,Michigan
Firstprinting,December2010
www.it-ebooks.info
Contents
ForewordbyDerekSivers xv
ForewordbyObieFernandez xvii
Acknowledgments xix
AbouttheAuthor xxi
Chapter1 FromZerotoDeploy 1
1.1 Introduction 3
1.1.1 CommentsforVariousReaders 4
1.1.2 “Scaling”Rails 7
1.1.3 ConventionsinThisBook 7
1.2 UpandRunning 9
1.2.1 DevelopmentEnvironments 9
1.2.2 Ruby,RubyGems,Rails,andGit 11
1.2.3 TheFirstApplication 15
1.2.4 Bundler 16
1.2.5 rails server 20
1.2.6 Model-View-Controller(MVC) 22
1.3 VersionControlwithGit 24
1.3.1 InstallationandSetup 24
1.3.2 AddingandCommitting 26
1.3.3 WhatGoodDoesGitDoYou? 28
1.3.4 GitHub 29
1.3.5 Branch,Edit,Commit,Merge 31
vii
www.it-ebooks.info
viii Contents
1.4 Deploying 35
1.4.1 HerokuSetup 36
1.4.2 HerokuDeployment,StepOne 37
1.4.3 HerokuDeployment,StepTwo 37
1.4.4 HerokuCommands 39
1.5 Conclusion 40
Chapter2 ADemoApp 41
2.1 PlanningtheApplication 41
2.1.1 ModelingUsers 43
2.1.2 ModelingMicroposts 44
2.2 TheUsersResource 44
2.2.1 AUserTour 46
2.2.2 MVCinAction 49
2.2.3 WeaknessesofThisUsersResource 58
2.3 TheMicropostsResource 58
2.3.1 AMicropostMicrotour 58
2.3.2 PuttingthemicroinMicroposts 61
2.3.3 AUserhas_manyMicroposts 63
2.3.4 InheritanceHierarchies 66
2.3.5 DeployingtheDemoApp 68
2.4 Conclusion 69
Chapter3 MostlyStaticPages 71
3.1 StaticPages 74
3.1.1 TrulyStaticPages 75
3.1.2 StaticPageswithRails 78
3.2 OurFirstTests 84
3.2.1 TestingTools 84
3.2.2 TDD:Red,Green,Refactor 86
3.3 SlightlyDynamicPages 103
3.3.1 TestingaTitleChange 103
3.3.2 PassingTitleTests 106
3.3.3 InstanceVariablesandEmbeddedRuby 108
3.3.4 EliminatingDuplicationwithLayouts 112
3.4 Conclusion 115
3.5 Exercises 116
www.it-ebooks.info
Contents ix
Chapter4 Rails-FlavoredRuby 119
4.1 Motivation 119
4.1.1 AtitleHelper 119
4.1.2 CascadingStyleSheets 122
4.2 StringsandMethods 125
4.2.1 Comments 125
4.2.2 Strings 126
4.2.3 ObjectsandMessagePassing 129
4.2.4 MethodDefinitions 132
4.2.5 BacktothetitleHelper 133
4.3 OtherDataStructures 134
4.3.1 ArraysandRanges 134
4.3.2 Blocks 137
4.3.3 HashesandSymbols 139
4.3.4 CSSRevisited 142
4.4 RubyClasses 144
4.4.1 Constructors 144
4.4.2 ClassInheritance 145
4.4.3 ModifyingBuilt-InClasses 148
4.4.4 AControllerClass 150
4.4.5 AUserClass 152
4.5 Exercises 154
Chapter5 FillingintheLayout 157
5.1 AddingSomeStructure 157
5.1.1 SiteNavigation 159
5.1.2 CustomCSS 164
5.1.3 Partials 171
5.2 LayoutLinks 177
5.2.1 IntegrationTests 178
5.2.2 RailsRoutes 181
5.2.3 NamedRoutes 183
5.3 UserSignup:AFirstStep 186
5.3.1 UsersController 186
5.3.2 SignupURL 188
5.4 Conclusion 191
5.5 Exercises 191
www.it-ebooks.info