OReilly ruby on rails up and running 2006 aug 2006 ISBN 0596101325

RubyonRails:UpandRunning
ByCurtHibbs,BruceA.Tate
...............................................
Publisher:O'Reilly
PubDate:August2006
PrintISBN-10:0-596-10132-5
PrintISBN-13:978-0-59-610132-9
Pages:182

TableofContents|Index

RubyonRailsisthesuper-productivenewwaytodevelopfull-featured
webapplications.WithRubyonRails,powerfulwebapplicationsthat
oncetookweeksormonthstodevelopcannowbeproducedinamatterof
days.Ifitsoundstoogoodtobetrue,itisn't.

Ifyou'relikealotofwebdevelopers,you'veprobablyconsidered
kickingthetiresonRails-theframeworkofchoiceforthenew
generationofWeb2.0developers.RubyonRails:UpandRunningfromO'Reillytakesyou
outforatestdriveandshowsyoujusthowfast
RubyonRailscango.

Thiscompactguideteachesyouthebasicsofinstallingandusingboth
theRubyscriptinglanguageandtheRailsframeworkforthequick
developmentofwebapplications.RubyonRails:Upand
Runningcoversjustabouteverythingyou
need-frommakingasimpledatabase-backedapplicationto
addingelaborateAjaxianfeaturesandallthejuicybitsinbetween.
WhileRailsispraisedforitssimplicityandspeedofdevelopment,
therearestillafewstepstomasterontheway.Moreadvanced
materialhelpsyoumapdatatoanimperfecttable,traversecomplex

relationships,andbuildcustomfinders.AsectiononworkingwithAjax
andRESTshowsyouhowtoexploittheRailsserviceframeworkstosend
emails,implementwebservices,andcreatedynamicuser-centricweb
pages.Thebookalsoexplainstheessentialsofloggingtofind
performanceproblemsanddelvesintootherperformanceoptimizing
techniques.


Asnewwebdevelopmentframeworksgo,RubyonRailsisthetalkofthe
town.AndRubyonRails:UpandRunningcanmake
sureyou'reinonthediscussion.


RubyonRails:UpandRunning
ByCurtHibbs,BruceA.Tate
...............................................
Publisher:O'Reilly
PubDate:August2006
PrintISBN-10:0-596-10132-5
PrintISBN-13:978-0-59-610132-9
Pages:182

TableofContents|Index

Copyright
Preface
Chapter1.ZerotoSixty:IntroducingRails
Section1.1.RailsStrengths
Section1.2.PuttingRailsintoAction
Section1.3.Organization
Section1.4.TheWebServer
Section1.5.CreatingaController
Section1.6.BuildingaView
Section1.7.TyingtheControllertotheView
Section1.8.UndertheHood
Section1.9.What'sNext?
Chapter2.ActiveRecordBasics
Section2.1.ActiveRecordBasics
Section2.2.IntroducingPhotoShare
Section2.3.SchemaMigrations
Section2.4.BasicActiveRecordClasses
Section2.5.Attributes
Section2.6.ComplexClasses
Section2.7.Behavior
Section2.8.MovingForward

Chapter3.ActiveRecordRelationships
Section3.1.belongs_to
Section3.2.has_many

Section3.3.has_one
Section3.4.WhatYouHaven'tSeen
Section3.5.LookingAhead
Chapter4.Scaffolding
Section4.1.UsingtheScaffoldMethod
Section4.2.ReplacingScaffolding
Section4.3.GeneratingScaffoldingCode
Section4.4.MovingForward
Chapter5.ExtendingViews
Section5.1.TheBigPicture
Section5.2.SeeingRealPhotos

Section5.3.ViewTemplates
Section5.4.SettingtheDefaultRoot
Section5.5.Stylesheets
Section5.6.HierarchicalCategories
Section5.7.StylingtheSlideshows
Chapter6.Ajax
Section6.1.HowRailsImplementsAjax
Section6.2.PlayingaSlideshow
Section6.3.UsingDrag-and-DroptoReorderSlides
Section6.4.DragandDropEverything(AlmostEverything)
Section6.5.FilteringbyCategory
Chapter7.Testing
Section7.1.Background
Section7.2.Ruby'sTest::Unit
Section7.3.TestinginRails
Section7.4.WrappingUp
AppendixA.InstallingRails
Section1.1.Windows
Section2.1.OSX
Section3.1.Linux
AppendixB.QuickReference
Section5.1.General
Section5.2.Testing
Section5.3.RJS(RubyJavaScript)
Section5.4.ActiveRecord
Section5.5.Controllers
Section5.6.Views
Section5.7.Ajax

Section5.8.ConfiguringYourApplication

AbouttheAuthors

Colophon

Index


RubyonRails:UpandRunning
byBruceA.TateandCurtHibbs
Copyright©2006O'ReillyMedia,Inc.Allrightsreserved.
PrintedintheUnitedStatesofAmerica.
PublishedbyO'ReillyMedia,Inc.,1005GravensteinHighway
North,Sebastopol,CA95472.
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Editor:

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Illustrators:

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PrintingHistory:



August2006:

FirstEdition.

NutshellHandbook,theNutshellHandbooklogo,andthe
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Manyofthedesignationsusedbymanufacturersandsellersto
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Whileeveryprecautionhasbeentakeninthepreparationofthis
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errorsoromissions,orfordamagesresultingfromtheuseof
theinformationcontainedherein.
ISBN-13:978-0-596-10132-9|ISBN-10:0-596-10132-5
[M]


Preface
TheRubyonRailsphenomenonissweepingthroughour
industrywithrecklessdisregardforestablishedprogramming
languages,longstandingconventions,orcommercialsupport.
YoucangetawholelotofinformationonRubyonRailsfrom
articlesontheWeb,excellentbooks,andevenformal

coursework.However,there'ssomethingmissing.Howdoesan
establishedprogrammer,armedwithnothingmorethanalittle
Rubyknowledge,gojustbeyondthebasics,andbeproductive
inRails?
WithRubyonRails:UpandRunning,wearenotgoingto
reiteratethereferencemanualorreplaceGoogle.Instead,we'll
strivetogiveyouthebigpictureofhowRailsapplicationshold
togetherandtellyouwheretogofortheinformationthatwe
don'tcoverinthechapters.YouwillseehowRailsdynamically
addsfeaturestoalldatabasemodels,calledActiveRecord
objects.Byunderstandingthebigpicture,you'llbeableto
makebetteruseofthebestreferencemanualstofillinthe
details.
Wewon'ttrytomakeyoudigestawholelotofwords.Instead,
we'llgiveyouthetheoryinthecontextofanend-to-end
application.We'llwalkyouthroughthecreationofasimple
projectonethatisalittlemoredemandingthanablogor
shoppingcart,butwithasimpleenoughstructurethataRails
beginnerwillbeabletoquicklyunderstandwhat'sgoingon.
We'renotgoingtotrytocovereachnewfeature.Instead,we'll
showyoutheonesweseeasthebackbone,formingthemost
importantelementstounderstand.Wewillalsocover
migrationsandAjaxinsomedetail,becauseyouwon'tfindtoo
muchinformationonthosetwoframeworksyet.
Inshort,we'renottryingtobuildacomprehensiveRailslibrary.


We'regoingtogiveyouthefoundationyouneedtogetupand
running.

WhoShouldReadThisBook?
RubyonRails:UpandRunningisforexperienceddevelopers
whoarenewtoRailsandpossiblytoRuby.Tousethisbook,
youdon'thavetobeastrongRubyprogrammer.Wedoexpect
youtobeaprogrammer,though.Youshouldknowenough
aboutyourchosenplatformtobeabletowriteprograms,install
software,runscriptsusingthesystemconsole,editfiles,usea
database,andunderstandhowbasicwebapplicationswork.

ConventionsUsedinThisBook
Thefollowingtypographicconventionsareusedinthisbook:

Plaintext
Indicatesmenutitles,menuoptions,menubuttons,and
keyboardaccelerators(suchasAltandCtrl).

Italic
Indicatesnewterms,URLs,emailaddresses,filenames,file
extensions,pathnames,directories,andUnixutilities.

Constantwidth
Indicatescommands,thecontentsoffiles,andtheoutput
fromcommands.


Constantwidthbold
Showscommandsorothertextthatshouldbetyped
literallybytheuser.

Constantwidthitalic

Showstextthatshouldbereplacedwithuser-supplied
values.

Thisiconsignifiesatip,suggestion,orgeneralnote.

Thisiconindicatesawarningorcaution.

UsingCodeExamples
Thisbookisheretohelpyougetyourjobdone.Ingeneral,you
mayusethecodeinthisbookinyourprogramsand
documentation.Youdonotneedtocontactusforpermission
unlessyou'rereproducingasignificantportionofthecode.For
example,writingaprogramthatusesseveralchunksofcode
fromthisbookdoesnotrequirepermission.Sellingor
distributingaCD-ROMofexamplesfromO'Reillybooksdoes
requirepermission.Answeringaquestionbycitingthisbook
andquotingexamplecodedoesnotrequirepermission.


Incorporatingasignificantamountofexamplecodefromthis
bookintoyourproduct'sdocumentationdoesrequire
permission.
YoucangetsamplecodeatthemainpageforRubyonRails:
UpandRunning:You
willfindaZIPfilethatcontainsthesampleprojectasitexists
aftereachchapter,witheachinstanceofthesampleapplication
numberedbychapter.Ifyouwanttoskipachapter,just
downloadtherightZIPfile.
Weappreciate,butdonotrequire,attribution.Anattribution

usuallyincludesthetitle,author,publisher,andISBN.For
example:"RubyonRails:UpandRunningbyBruceA.Tateand
CurtHibbs.Copyright2006O'ReillyMedia,Inc.,978-0-59610132-9."
Ifyoufeelthatyouruseofcodeexamplesfallsoutsidefairuse
orthepermissiongivenhere,feelfreetocontactusat


Platforms
RubyonRailsiscross-platform,butUnixandWindowsshells
behavedifferently.Forconsistency,weuseWindowsthroughout
thebook.YoucaneasilyruntheexamplesontheUnixorMac
OSXoperatingsystemsaswell.You'llseeacoupleofminor
differences:
OnWindows,youcanspecifypathswitheithertheforward
slash(/)orbackslash(\)character.We'lltrytobe
consistentandusetheforwardslashtospecifyallpaths.
OnWindows,torunthevariousRubyscriptsthatmakeup
Rails,youneedtoexplicitlytyperuby.OnUnix
environments,youdon't.Ifyou'rerunningUnix,andyou


areinstructedtotypethecommandrubyscript/server,feel
freetoomittheruby.
OnWindows,torunaprocessinaseparateshell,precede
thecommandwithstart.OnUnixandMacOSX,appendan
ampersand(&)charactertorunthecommandinthe
background.

Safari®Enabled
WhenyouseeaSafari®Enabledicononthecoverof

yourfavoritetechnologybook,thatmeansthebookisavailable
onlinethroughtheO'ReillyNetworkSafariBookshelf.
Safarioffersasolutionthat'sbetterthane-books.It'savirtual
librarythatletsyoueasilysearchthousandsoftoptechbooks,
cutandpastecodesamples,downloadchapters,andfindquick
answerswhenyouneedthemostaccurate,currentinformation.
Tryitforfreeat.

HowtoContactUs
Wehavetestedandverifiedtheinformationinthisbookandin
thesourcecodetothebestofourability,butgiventheamount
oftextandtherapidevolutionoftechnology,youmayfindthat
featureshavechangedorthatwehavemademistakes.Ifso,
pleasenotifyusbywritingto:
O'ReillyMedia,Inc.
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Sebastopol,CA95472
800-998-9938(intheUnitedStatesorCanada)


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Youcanalsosendmessageselectronically.Tobeputonthe
mailinglistorrequestacatalog,sendemailto:

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Asmentionedintheearliersection,wehaveawebsiteforthis
bookwhereyoucanfindcode,errata(previouslyreported

errorsandcorrectionsavailableforpublicview),andotherbook
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/>Formoreinformationaboutthisbookandothers,seethe
O'Reillywebsite:


Acknowledgments
Writingabookisademandingexercise,takingpassion,
commitment,andpersistence.Theauthorsonthecovergetall
oftheglory(andpossiblytheblame).Manypeoplecontribute
toabook.We'dliketomentionthepeoplewhomadewriting
thisbooksuchafulfillingexperience.
Collectively,CurtandBrucewouldliketothanktheoutstanding


teamofreviewerswhoprovidedsomanygreatcomments,
includingDavidMabelle,MauroCicio,BrookeHedrick,Faisal
Jawdat,ShaneClaussen,LeodeBlaauw,AnneBowman,Seth
Havermann,DaveHastings,andRandyHanford.We'dalsolike
tothankDavidGearyforfleshingoutsomeoftheearlyideasin
PhotoShare.
RubyonRails:UpandRunningwouldbenothingwithoutthe
excellentcontributionsofthecoreRubyonRailsteam.We
wouldliketothankDavidHeinemeierHansson(thecreatorof
Rails),FlorianWeber,JamisBuck,JeremyKemper,LeonBreedt,
MarcelMolina,Jr.,MichaelKoziarski,NicholasSeckar,Sam
Stephenson,ScottBarron,ThomasFuchs,andTobiasLuetke.
Rubyisafantasticlanguage,andwewouldliketothankthe
manywhomadeitso.WethrowoutspecificthankstoYukihiro
Matsumoto(a.k.a."Matz"),thecreatorofRuby,andtoDave

ThomasandAndyHunt,withoutwhomRubymighthave
remainedvirtuallyunknownoutsideofJapan.
BrucewouldliketospecificallythankCurt,forsteppingintothis
projectafteritseemedthatitwasdead.Also,thankstothose
atAutoGaswhoweresoinstrumentalintryingthistechnology
withinthecontextofarealproductionapplicationespeciallythe
coredevelopmentteam,includingMathewVarghese,Karl
Hoenshel,CheriByerley,ChrisGindorf,andColbyBlaisdell.
Theircollectiveexperienceshapedthisbookmorethanyouwill
everknow.ThankstomyDutchfriendLeo,again,forbeing
suchasupportiveinfluenceonthisbook,thoughyou'remostly
aJavadeveloper.Youhavehadmoreinfluenceonmethanyou
mightexpect.Morethananyoneelse,Iwouldliketothankmy
family.KaylaandJulia,youarethesparksinmysoulthatkeep
thecreativefiresburning.Maggie,youaremyinspiration,andI
loveyoumorethanIcaneversay.
Curtwouldliketothankhiswife,Wasana,forlettinghim
disappearbehindhiscomputerscreenlateintothenight(and
sometimesintothefollowingday)withoutcomplaint.Iwould
alsoliketothankmyfriendsatO'Reilly,forgivingmeaforum


tospreadthewordabouttheincredibleproductivityadvantages
ofRubyonRails.Specifically,I'dliketothankchromaticfor
publishingmyONLamp.comarticles,andMikeLoukidesfornot
givingupwhenIkepttellinghimIdidn'twanttowriteabook.


Chapter1.ZerotoSixty:Introducing
Rails

Railsmayjustbethemostimportantopensourceprojecttobe
introducedinthepast10years.It'spromotedasoneofthe
mostproductivewebdevelopmentframeworksofalltimeandis
basedontheincreasinglyimportantRubyprogramming
language.Whathashappenedsofar?
ByDecember2006,you'relikelytoseemorepublished
booksonRailsthananyofJava'ssingleflagship
frameworks,includingJSF,Spring,orHibernate.
TheRailsframeworkhasbeendownloadedatleast500,000
timesinonlyitssecondyear,asofMay2006.These
statisticscomparefavorablywiththemostpopularopen
sourceframeworksinanylanguage.[*]
[*]Thenumber500,000isactuallyaconservativeestimate.Downloadstatisticsforapopulardelivery
vehicle,calledgems,makeiteasytotrackthenumberofRailsdistributionsbygems,butmanyother
distributionsexist,suchastheLocomotivedistributiononMacOSX.Therealdownloadstatisticscould
easilybetwicethisnumber.

TheRailscommunitymailinglistsgethundredsofnotesa
day,comparedtodozensonthemostpopularweb
developmentframeworksinotherlanguages.
TheRailsframeworkhascausedanexplosionintheuseof
theRubyprogramminglanguage,whichhasbeenrelatively
obscureuntilrecently.
TheRailsbuzzgeneratesincreasinglyhotdebateson
portalsthatfocusonotherprogramminglanguages.The
JavacommunityinparticularhasfiercelydebatedtheRails


platform.
Youdon'thavetogofartofindgreatoverviewsofRails.You

canwatchseveraleducationalvideosthatshowRailsinaction,
narratedbythefounderDavidHeinemeierHansson.Youcan
watchhimbuildsimpleworkingapplications,completewitha
backingdatabaseandvalidation,inlessthan10minutes.But
unlikethemanyquick-and-dirtyenvironmentsyou'veseen,
Railsletsyoukeepthequickandleavethedirtybehind.Itlets
youbuildcleanapplicationsbasedonthemodel-view-controller
philosophy.Railsisaspecialframework.
Sure,Railshasitslimitations.Rubyhaspoorsupportforobjectrelationalmapping(ORM)forlegacyschemas;theRails
approachislesspowerfulthanJava'sapproach,forexample.[*]
Rubydoesnotyethaveflagshipintegrateddevelopment
environments.Everyframeworkhaslimitations,andRailsisno
different.Butforawiderangeofapplications,thestrengthsof
Railsfaroutpaceitsweaknesses.
[*]Forexample,Hibernatesupportsthreekindsofinheritancemapping,butRailssupportsonlysingle-table
inheritance.Hibernatesupportscompositekeys,butRailsismuchmorelimited.


1.1.RailsStrengths
Asyougothroughthisbook,you'lllearnhowRailscanthrive
withoutalloftheextensivelibrariesrequiredbyother
languages.Ruby'sflexibilityletsyouextendyourapplicationsin
waysthatmighthavebeenpreviouslyunavailabletoyou.You'll
beabletouseaRailsfeaturecalledscaffoldingtoputdatabasebackeduserinterfacesinfrontofyourcustomersquickly.Then,
asyouimproveyourcode,thescaffoldingmeltsaway.You'llbe
abletobuilddatabase-backedmodelobjectswithjustacouple
oflinesofcode,andRailswillfillinthetediousdetails.
Themostcommonprogrammingproblemintoday'stypical
developmentprojectinvolvesbuildingaweb-baseduser
interfacetomanagearelationaldatabase.Forthatclassof

problems,Railsismuchmoreproductivethananyotherweb
developmentframeworkeitherofushaseverused.The
strengthsaren'tlimitedtoanysinglegroundbreakinginvention;
rather,Railsispackedwithfeaturesthatmakeyoumore
productive,withmanyofthefollowingfeaturesbuildingonone
other:

Metaprogramming
Metaprogrammingtechniquesuseprogramstowrite
programs.Otherframeworksuseextensivecode
generation,whichgivesusersaone-timeproductivityboost
butlittleelse,andcustomizationscriptslettheuseradd
customizationcodeinonlyasmallnumberofcarefully
selectedpoints.Metaprogrammingreplacesthesetwo
primitivetechniquesandeliminatestheirdisadvantages.
Rubyisoneofthebestlanguagesformetaprogramming,
andRailsusesthiscapabilitywell.[ ]


[ ]Railsalsousescodegenerationbutreliesmuchmoreonmetaprogrammingfortheheavy
lifting.

ActiveRecord
RailsintroducestheActiveRecordframework,whichsaves
objectstothedatabase.Basedonadesignpattern
catalogedbyMartinFowler,theRailsversionofActive
Recorddiscoversthecolumnsinadatabaseschemaand
automaticallyattachesthemtoyourdomainobjectsusing
metaprogramming.Thisapproachtowrappingdatabase
tablesissimple,elegant,andpowerful.

Conventionoverconfiguration
Mostwebdevelopmentframeworksfor.NETorJavaforce
youtowritepagesofconfigurationcode.Ifyoufollow
suggestednamingconventions,Railsdoesn'tneedmuch
configuration.Infact,youcanoftencutyourtotal
configurationcodebyafactoroffiveormoreoversimilar
Javaframeworksjustbyfollowingcommonconventions.

Scaffolding
Youoftencreatetemporarycodeintheearlystagesof
developmenttohelpgetanapplicationupquicklyandsee
howmajorcomponentsworktogether.Railsautomatically
createsmuchofthescaffoldingyou'llneed.

Built-intesting


Railscreatessimpleautomatedtestsyoucanthenextend.
Railsalsoprovidessupportingcodecalledharnessesand
fixturesthatmaketestcaseseasiertowriteandrun.Ruby
canthenexecuteallyourautomatedtestswiththerake
utility.

Threeenvironments:development,testing,andproduction
Railsgivesyouthreedefaultenvironments:development,
testing,andproduction.Eachbehavesslightlydifferently,
makingyourentiresoftwaredevelopmentcycleeasier.For
example,RailscreatesafreshcopyoftheTestdatabasefor
eachtestrun.

There'smuchmore,too,includingAjaxforrichuserinterfaces,
partialviewsandhelpersforreusingviewcode,built-incaching,
amailingframework,andwebservices.Wecan'tgettoallof
Rails'featuresinthisbook;however,wewillletyouknow
wheretogetmoreinformation.Butthebestwaytoappreciate
Railsistoseeitinaction,solet'sgettoit.




1.2.PuttingRailsintoAction
YoucouldmanuallyinstallallofthecomponentsforRails,but
Rubyhassomethingcalledgems.Thegeminstalleraccessesa
website,RubyForge,anddownloadsanapplicationunit,called
agem,andallitsdependencies.YoucaninstallRailsthrough
gems,requestingalldependencies,withthiscommand:[*]
[*]Ifyouwanttocodealongwithus,makesureyou'veinstalledRubyandgems.AppendixAcontainsdetailed
installationinstructions.

geminstallrails--include-dependencies

That'sitRailsisinstalled.There'sonecaveat:youalsoneedto
installthedatabasesupportforyourgivendatabase.Ifyou've
alreadyinstalledMySQL,you'redone.Ifnot,goto
formoredetailsonRailsinstallation.
Next,here'showtocreateaRailsproject:


MVCandModel2
Inthemid-1970s,theMVC(model-view-controller)strategyevolvedinthe

Smalltalkcommunitytoreducecouplingbetweenbusinesslogicandpresentation
logic.WithMVC,youputyourbusinesslogicintoseparatedomainobjectsand
isolateyourpresentationlogicinaview,whichpresentsdatafromdomain
objects.Thecontrollermanagesnavigationbetweenviews,processesuserinput,
andmarshalsthecorrectdomainobjectsbetweenthemodelandview.Good
programmershaveusedMVCeversince,implementingMVCapplicationsusing
frameworkswritteninmanydifferentlanguages,includingRuby.
WebdevelopersuseasubtlydifferentvariantofMVCcalledModel2.Model2uses
thesameprinciplesofMVCbuttailorsthemforstatelesswebapplications.In
Model2applications,abrowsercallsacontrollerviawebstandards.The
controllerinteractswiththemodeltogetdataandvalidateuserinput,andthen
makesdomainobjectsavailabletotheviewfordisplay.Next,thecontroller
invokesthecorrectviewgenerator,basedonvalidationresultsorretrieveddata.
Theviewlayergeneratesawebpage,usingdataprovidedbythecontroller.The
frameworkthenreturnsthewebpagetotheuser.IntheRailscommunity,when
someonesaysMVC,they'rereferringtotheModel2variant.
Model2hasbeenusedinmanysuccessfulprojectsspreadacrossmany
programminglanguages.IntheJavacommunity,Strutsisthemostcommon
Model2framework.InPython,theflagshipwebdevelopmentframeworkcalled
ZopeusesModel2.Youcanreadmoreaboutthemodel-view-controllerstrategy
at />
>railschapter-1
create
createapp/controllers
createapp/helpers
createapp/models
createapp/views/layouts
createconfig/environments
createcomponents
createdb

createdoc
createlib


...
createtest/mocks/development
createtest/mocks/test
createtest/unit
createvendor
...
createapp/controllers/application.rb
createapp/helpers/application_helper.rb
createtest/test_helper.rb
createconfig/database.yml
...

Wetruncatedthelist,butyougetthepicture.


1.3.Organization
Thedirectoriescreatedduringinstallationprovideaplacefor
yourcode,scriptstohelpyoumanageandbuildyour
application,andmanyothergoodies.Later,we'llexaminethe
mostinterestingdirectoriesingreaterdetail.Fornow,let'stake
aquickpassthroughthedirectorytreeintheprojectwe
created:

app
Thisapplicationorganizesyourapplicationcomponents.It's
gotsubdirectoriesthatholdtheview(viewsandhelpers),

controller(controllers),andthebackendbusinesslogic
(models).

components
Thisdirectoryholdscomponentstinyself-contained
applicationsthatbundlemodel,view,andcontroller.

config
Thisdirectorycontainsthesmallamountofconfiguration
codethatyourapplicationwillneed,includingyour
databaseconfiguration(indatabase.yml),yourRails
environmentstructure(environment.rb),androutingof
incomingwebrequests(routes.rb).Youcanalsotailorthe
behaviorofthethreeRailsenvironmentsfortest,
development,anddeploymentwithfilesfoundinthe
environmentsdirectory.


db
Usually,yourRailsapplicationwillhavemodelobjectsthat
accessrelationaldatabasetables.Youcanmanagethe
relationaldatabasewithscriptsyoucreateandplaceinthis
directory.

doc
Rubyhasaframework,calledRubyDoc,thatcan
automaticallygeneratedocumentationforcodeyoucreate.
YoucanassistRubyDocwithcommentsinyourcode.This
directoryholdsalltheRubyDoc-generatedRailsand
applicationdocumentation.

lib
You'llputlibrarieshere,unlesstheyexplicitlybelong
elsewhere(suchasvendorlibraries).

log
Errorlogsgohere.Railscreatesscriptsthathelpyou
managevariouserrorlogs.You'llfindseparatelogsforthe
server(server.log)andeachRailsenvironment
(development.log,test.log,andproduction.log).

public