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OReilly XML publishing with axkit jun 2004 ISBN 0596002165










TableofContents
Index
Reviews
ReaderReviews
Errata
Academic

XMLPublishingwithAxKit
ByKipHampton

Publisher :O'Reilly
PubDate :June2004

ISBN :0-596-00216-5
Pages :216


XMLPublishingwithAxKitpresentsweb
programmerstheknowledgetheyneedto
masterAxKit.Thebookfeaturesathorough
introductiontoXSP(extensibleServer
Pages),whichappliestheconceptsofServer
Pagestechnologies(embeddedcode,tag
libraries,etc)totheXMLworld,andcovers
integratingAxKitwithothertoolssuchas
TemplateToolkit,Apache::Mason,


Apache::ASP,andplainCGI.Italsoincludes
invaluablereferencesectionsonconfiguration
directives,XPathScript,andXSP.











TableofContents
Index
Reviews
ReaderReviews
Errata
Academic

XMLPublishingwithAxKit
ByKipHampton

Publisher :O'Reilly
PubDate :June2004
ISBN :0-596-00216-5
Pages :216



Copyright

Preface
WhoShouldReadThisBook

What'sInside




ConventionsUsedinThisBook




HowtoContactUs

UsingCodeExamples
Acknowledgments


Chapter1.XMLasaPublishingTechnology
Section1.1.ExplodingaFewMythsAboutXMLPublishing

Section1.2.XMLBasics






Section1.3.PublishingXMLContent
Section1.4.IntroducingAxKit,anXMLApplicationServerforApache
Chapter2.InstallingAxKit
Section2.1.InstallationRequirements






Section2.2.InstallingtheAxKitCore




Section2.4.BasicServerConfiguration

Section2.3.InstallingAxKitonWin32Systems
Section2.5.TestingtheInstallation

Section2.6.InstallationTroubleshooting


Chapter3.YourFirstXMLWebSite
Section3.1.Preparation




Section3.2.CreatingtheSourceXMLDocuments




Section3.4.AssociatingtheDocumentswiththeStylesheet

Section3.3.WritingtheStylesheet
Section3.5.AStepFurther:SyndicatingContent


Chapter4.PointsofStyle
Section4.1.AddingTransformationLanguageModules

Section4.2.DefiningStyleProcessors




Section4.3.DynamicallyChoosingStyleTransformations
Section4.4.StyleProcessorConfigurationCheatsheet


Chapter5.TransformingXMLContentwithXSLT
Section5.1.XSLTBasics

Section5.2.ABriefXSLTCookbook


Chapter6.TransformingXMLContentwithXPathScript
Section6.1.XPathScriptBasics

Section6.2.TheTemplateHash:ACloserLook

Section6.3.XPathScriptCookbook


Chapter7.ServingDynamicXMLContent
Section7.1.IntroductiontoeXtensibleServerPages

Section7.2.OtherDynamicXMLTechniques


Chapter8.ExtendingAxKit
Section8.1.AxKit'sArchitecture




Section8.2.CustomPlug-ins




Section8.4.CustomLanguageModules

Section8.3.CustomProviders
Section8.5.CustomConfigReaders

Section8.6.GettingMoreInformation


Chapter9.IntegratingAxKitwithOtherTools
Section9.1.TheTemplateToolkit

Section9.2.ProvidingContentviaApache::Filter


AppendixA.AxKitConfigurationDirectiveReference
SectionA.1.AxCacheDir



SectionA.2.AxNoCache




SectionA.3.AxDebugLevel




SectionA.4.AxTraceIntermediate




SectionA.6.AxStackTrace




SectionA.8.AxAddPlugin




SectionA.10.AxTranslateOutput




SectionA.12.AxExternalEncoding




SectionA.14.AxResetOutputTransformers




SectionA.16.AxAddXSPTaglib




SectionA.18.AxHandleDirs




SectionA.20.AxMedia




SectionA.22.AxResetStyleMap




SectionA.24.AxAddDocTypeProcessor




SectionA.26.AxAddRootProcessor




SectionA.28.AxResetProcessors

SectionA.5.AxDebugTidy
SectionA.7.AxLogDeclines
SectionA.9.AxGzipOutput
SectionA.11.AxOutputCharset
SectionA.13.AxAddOutputTransformer
SectionA.15.AxErrorStylesheet
SectionA.17.AxIgnoreStylePI
SectionA.19.AxStyle
SectionA.21.AxAddStyleMap
SectionA.23.AxAddProcessor
SectionA.25.AxAddDTDProcessor
SectionA.27.AxAddURIProcessor
SectionA.29.

SectionA.30.


Colophon

Index


Copyright©2004O'ReillyMedia,Inc.
PrintedintheUnitedStatesofAmerica.
PublishedbyO'ReillyMedia,Inc.,1005GravensteinHighway
North,Sebastopol,CA95472.
O'Reillybooksmaybepurchasedforeducational,business,or
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mosttitles(http://safari.oreilly.com).Formoreinformation,
contactourcorporate/institutionalsalesdepartment:(800)
998-9938orcorporate@oreilly.com.
NutshellHandbook,theNutshellHandbooklogo,andthe
O'ReillylogoareregisteredtrademarksofO'ReillyMedia,Inc.
XMLPublishingwithAxKit,theimageoftarpans,andrelated
tradedressaretrademarksofO'ReillyMedia,Inc.
Manyofthedesignationsusedbymanufacturersandsellersto
distinguishtheirproductsareclaimedastrademarks.Where
thosedesignationsappearinthisbook,andO'ReillyMedia,Inc.
wasawareofatrademarkclaim,thedesignationshavebeen
printedincapsorinitialcaps.
Manyofthedesignationsusedbymanufacturersandsellersto
distinguishtheirproductsareclaimedastrademarks.Where
thosedesignationsappearinthisbook,andO'ReillyMedia,Inc.
wasawareofatrademarkclaim,thedesignationshavebeen
printedincapsorinitialcaps.
Whileeveryprecautionhasbeentakeninthepreparationofthis
book,thepublisherandauthorsassumenoresponsibilityfor
errorsoromissions,orfordamagesresultingfromtheuseof
theinformationcontainedherein.


Preface
ThisbookintroducesApacheAxKit,amod_perl-basedextension
totheApachewebserverthatturnsApacheintoanXML
publishingandapplicationenvironment.


WhoShouldReadThisBook
Thisbookisintendedtobeusefultoanyweb
developer/designerinterestedinlearningaboutXMLpublishing,
ingeneral,andthepracticalaspectsofXMLpublishing,
specificallywiththeApacheAxKitXMLapplicationand
publishingserver.WhileAxKitanditstechniquesarethe
obviousfocus,manyideaspresentedcanbereusedinother
XML-basedpublishingenvironments.IfyoudonotknowXML
anddreadthethoughtofconsumingapileofesoteric
specificationstounderstandwhatisbeingpresented,don't
worrythisbooktakesafiercelypragmaticapproachthatwill
teachyouonlywhatyouneedtoknowtobeproductivewith
AxKit.AquickscanofXML'sbasicsyntaxisprobablyalltheXML
knowledgeyouneedtogetstarted.
AlthoughAxKitiswritteninPerl,itsusersneednotknowPerlat
alltouseittoitsfulleffect.However,developerswhodoknow
PerlwillfindthatAxKit'smodulardesignallowsthemtoeasily
writecustomextensionstomeetspecializedrequirements.
Similarly,AxKitusersarenotexpectedtobeApacheHTTP
servergurus,butthosewhodoknowevenabitabouthow
Apacheworkswillfindthemselveswithavaluableheadstart:
WebdeveloperswilllearnXMLpublishingtechniques
throughavarietyofpractical,testedexamples.
PerlprogrammerswillseehowtheycanuseXMLtobuildon
theirexistingskills.
MarkupprofessionalswilldiscoverhowAxKitcombines
standardXMLprocessingtoolswiththoseuniquetothePerl
programminglanguagetocreateaflexible,easy-to-use
environmentthatdeliversonXML'spromiseasapublishing


technology.


What'sInside
Thisbookisorganizedintoninechaptersandoneappendix.
Chapter1,XMLasaPublishingTEchnology,putsXMLinto
perspectiveasamarkuplanguage,presentssomeofthetopics
commonlyassociatedwithXMLpublishing,andintroducesAxKit
asanXMLapplicationandpublishingenvironment.
Chapter2,InstallingAxKit,guidesyouthroughtheprocessof
installingAxKit,includingitsdependenciesandoptional
modules.Thischapteralsocoversplatform-specificinstallation
tips,howtonavigateAxKit'sinstalleddocumentation,and
wheretogoforadditionalhelp.
Chapter3,YourFirstXMLWebSite,guidesyouthroughthe
processofcreatingandpublishingasimpleXML-basedwebsite
usingAxKit.Specialattentionispaidtothebasicprinciplesand
techniquescommontomostprojects.
Chapter4,PointsofStyle,detailsAxKit'sstyleprocessing
directives.Itgivesspecialattentiontohowtocombinevarious
directivestocreatebothsimpleandcomplexprocessingchains,
andhowtoconditionallyapplyalternatetransformationsusing
AxKit'sStyleChooserandMediaChooserplug-ins.
Chapter5,TransformingXMLContentwithXSLT,offersa
"quickstart"introductiontoXSLT1.0andhowtouseit
effectivelywithinAxKit.ACookbook-stylesectionoffers
solutionstocommondevelopmenttasks.
Chapter6,TransformingXMLContentwithXPathScript,
introducesAxKit'smorePerl-centricalternativetoXSLT,
XPathScript.ThefocusisonXPathScript'sbasicsyntaxand
templateoptionsforgeneratingandtransformingXMLcontent.
ThechapteralsocontainsaCookbook-stylesection.


Chapter7,ServingDynamicXMLContentwithXPathScript,
presentsanumberoftoolsandtechniquesthatcanbeusedto
generatedynamicXMLcontentfromwithinAxKit.Thefocusis
onAxKit'simplementationofeXtensibleServerPages(XSP)and
onhowtocreatereusableXSPtaglibrariesthatmapXML
elementstofunctionalcode,aswellasonhowtousePerl's
SAWAweb-applicationframeworktoprovidedynamiccontentto
AxKit.
Chapter8,ExtendingAxKit,introducesAxKit'sunderlying
architectureandoffersadetailedviewofeachofitsmodular
components.Thechapterpaysspecialattentiontohowandwhy
developersmaydevelopcustomcomponentsforAxKitand
providesadetailedAPIreferenceforeachcomponentclass.
Chapter9,IntegratingAxKitwithOtherTools,showshowto
useAxKitinconjunctionwithotherpopularweb-development
technologies,fromplainCGItoMasonandtheTemplateToolkit.
AppendixA,TheAxKitConfigurationDirectiveReference,
providesacompletelistofconfigurationblocksanddirectives.


ConventionsUsedinThisBook
Thefollowingtypographicalconventionsareusedinthisbook:

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

Constantwidth
Indicatescommands,options,switches,variables,
attributes,keys,functions,types,classes,namespaces,
methods,modules,properties,parameters,values,objects,
events,eventhandlers,XMLtags,HTMLtags,macros,the
contentsoffiles,ortheoutputfromcommands.

Constantwidthitalic
Showstextthatshouldbereplacedwithuser-supplied
values.

Constantwidthbold
Showscommandsorothertextthattheusershouldtype
literally.

Thisiconsignifiesatip,suggestion,orgeneralnote.


Thisiconindicatesawarningorcaution.


UsingCodeExamples
Thisbookisheretohelpyougetyourjobdone.Ingeneral,you
mayusethecodeinthisbookinyourprogramsand
documentation.Youdonotneedtocontactusforpermission
unlessyou'rereproducingasignificantportionofthecode.For
example,writingaprogramthatusesseveralchunksofcode
fromthisbookdoesnotrequirepermission.Sellingor
distributingaCD-ROMofexamplesfromO'Reillybooksdoes
requirepermission.Answeringaquestionbycitingthisbook
andbyquotingexamplecodedoesnotrequirepermission.
Incorporatingasignificantamountofexamplecodefromthis
bookintoyourproduct'sdocumentationdoesrequire
permission.
Weappreciate,butdonotrequire,attribution.Anattribution
usuallyincludesthetitle,author,publisher,andISBN.For
example:"XMLPublishingwithAxKit,byKipHampton.
Copyright2004O'ReillyMedia,Inc.,0-596-00216-5."
Ifyoufeelyouruseofcodeexamplesfallsoutsidefairuseor
thepermissiongivenabove,feelfreetocontactusat
permissions@oreilly.com.


HowtoContactUs
WeatO'Reillyhavetestedandverifiedtheinformationinthis
booktothebestofourability,butyoumayfindthatfeatures
havechanged(oreventhatwehavemademistakes!).Please
letusknowaboutanyerrorsyoufind,aswellasyour
suggestionsforfutureeditions,bywritingto:
O'ReillyMedia,Inc.
1005GravensteinHighwayNorth
Sebastopol,CA95472
(800)998-9938(intheUnitedStatesorCanada)
(707)829-0515(internationalorlocal)
(707)829-0104(fax)
Wehaveawebpageforthisbook,wherewelisterrata,
examples,oranyadditionalinformation.Youcanaccessthis
pageat:
http://www.oreilly.com/catalog/xmlaxkit/
Tocommentorasktechnicalquestionsaboutthisbook,send
emailto:
bookquestions@oreilly.com
Youcansignupforoneormoreofourmailinglistsat:
http://elists.oreilly.com
Formoreinformationaboutourbooks,conferences,software,
ResourceCenters,andtheO'ReillyNetwork,seeourwebsite
at:
http://www.oreilly.com
Youmayalsowritedirectlytotheauthorat


khampton@totalcinema.com.


Acknowledgments
Iwouldliketothankmyeditor,SimonSt.Laurent,forhis
wisdomandfeedback,andthegoodfolksatO'Reillyfor
standingbehindthisbookandseeingitthroughtocompletion.
ThankstoMattSergeantforcodingAxKitinthefirstplaceand
toMatt,BarrieSlaymaker,KenMacLeod,MichaelRodriguez,
GrantMcLean,andthemanyothermembersofthePerl/XML
communityfortheirtirelesseffortsandgeneralmarkup
processingwizardry.Thanks,andaheartyandheartfelt
"DAHUT!"toRobinBerjon,JörgWalter,MichaelKröll,Steve
Willer,MikeNachbaur,ChrisPrather,andtheothercryptid
denizensoftheAxKitcabal.Finally,specialthanksgoouttomy
family,especiallytomybrother,Jason,whosepatience,
support,andencouragementtrulymadethisbookpossible.


Chapter1.XMLasaPublishing
Technology
IntheearlydaysofthecommercialWeb,otherwisereasonable
andintelligentpeopleboughtintothenotionthatsimplyhaving
apubliclyavailablewebsitewasenough.Enoughtogettheir
companynoticed.Enoughtobecomeamajorplayerinthe
globalmarket.Enoughtocapturethatmagicalandvaguely
definedcommoditycalledmarketshare.Somehowthatwould
beenoughtoensurethatconsumersandinvestorswouldpour
outbagsofmoneyonthestepsofcompanyheadquarters.In
thoseheadydays,budgetsforweb-relatedtechnologies
appearedlimitless,andthedevelopmentpracticesofthetime
reflectedthatitseemedperfectlyreasonabletofollowthe
celebrationofasite'srolloutwithinitialdiscussionsaboutwhat
thenextversionofthatsitewouldlooklikeanddo.
(Sometimes,thenextredesignwasalreadyintheworksbefore
thecurrentredesignwasevenlaunched.)Itdidnotmatter,
technically,thatasitewaslargelyhardcodedandinflexible,or
thatthescriptsthatimplementedthedynamicapplications
weremessyandimpossibletomaintainovertime.What
matteredwasthattheprojectwasdonequickly.Ifafewbad
choicesweremadealongtheway,itwasthought,theycould
alwaysbeaddressedduringtheinevitableredesign.
Thosedaysaregone.
Thegoldrushmentalityhasrecededandcompaniesandother
organizationsarelookingformorefromtheirinvestmentinthe
Web.Simplyhavingasiteoutthereisnotenough(andtruly,it
neverwas).Thesitemustdosomethingthatmeasurablyadds
valuetotheorganizationandthatvaluemustexceedthecost
ofdevelopingthesiteinthefirstplace.Inotherwords,theNew
Economyhadaratherabruptintroductiontotherulesof
BusinessAsUsual.Thisindustry-widebelt-tighteningmeans


thatwebdevelopersmustadjusttheirapproachtoproduction.
Companiescannolongeraffordtowriteoffthetimeandenergy
investedindevelopingawebsitesimplytoreplaceitwith
somethinglargelysimilar.Developersareexpectedtoprovide
dynamic,malleablesolutionsthatcanevolveovertimeto
includenewcontent,dynamicfeatures,andsupportfornew
typesofclientsoftware.Inshort,today'sdevelopersarebeing
askedtodomorewithless.Theyneedtoolsthatcancopewith
majorchangestoasiteoranapplicationwithoutalteringthe
foundationthatisalreadythere.
Farfrombeingastoryofgloomanddoom,theslimmingofweb
budgetshasledtoanaturalandpositivereevaluationofthe
toolsandtechniquesthatgointodevelopingandmaintaining
onlinemediaandapplications.Theneedtoprovidemore
optionswithfewerresourcesisdrivingthecreative
developmentofhigher-levelapplicationandpublishing
frameworksthatarebetterabletomeetchangingrequirements
overtimewithaminimumofduplicatedeffort.Ironically,in
manyways,the"dotbomb"wasthebestthingthatcouldhave
happenedtowebsoftware.
Onekeyconceptbehindtoday'smoreadaptivewebsolutions
liesinmakingsurethatthecontentofthesiteisreusable.By
reusablecontentImeanthattheessentialinformationis
captured(oravailable)inawaythatlendsitselftodifferent
usesorviewsofthatdatabasedonthecontextinwhichitis
beingrequested.Consider,forexample,thetaskofpublishing
aninformalessayaboutthelifeofJazzgreatLouisArmstrong.
Presumingyouwillonlybepublishingthisdocumentviathe
Web,youstillhaveavarietyofchoicesabouttheforminwhich
thedocumentwillbeavailable.YoucouldpublishitinHTMLfor
fasterdownloadingorPDFforfinercontroloverthevisual
layout.IfyoulimitthechoicetoHTML,youstillhavemany
choicestomakewhatlinks,adbanners,andothersupporting
contentwillyouinclude?Doesthedataincludeageneric
boilerplatethatisthesameforeverypageonthesite,orwill


youattempttoprovideamoreintimatesenseofcontextby
providinglinkstootherrelatedtopics?Ifyouwanttooffera
senseofcontext,howdoyoudecidewhatisrelated?Doyou
frametheessayinthecontextofinfluentialJazzmusicians,
prominentAfricanAmericans,orfamousnativesofNew
Orleans?Giventhateachofthesecontextsisarguablyvalid,
whatifyouwanttopresentallthreeandlettheuserdecide
whichnavigationalpathsuitsherinterestsbest?Youcouldalso
saythattheessay'smetadata(itstitle,author'sname,abstract
summary,etc.)isreallyjustanotherwayoflookingatthesame
document,albeitahighlyselectiveandfilteredone.Eachof
thesechoicesrepresentsnothingmorethananalternative
contextualviewofthesamecontent(theArmstrongessay).All
thatreallychangesisthewayinwhichthatcontentis
presented.
Figure1-1showsasimplerepresentationofyouressayand
someofitspossiblealternateviews.Howcouldyouhitallof
thesetargets?Obviously,youcouldhand-authorthedocument
ineachofthevariousformatsandcontexts,butthatwouldbe
time-consumingandunrealisticforallbutthetiniestofsites.
Ideally,whatyouwantisasystemthat:
Storesthedatainarichandmeaningfulwaysouserscan
accessiteasilyatvariouslevelsofdetail
Providesaneasywaytoaddalternate(expandedor
filtered)viewsofthatdatawithoutrequiringchangestothe
sourcedocument(or,inthecaseofdynamiccontent,the
codethatgeneratesit)

Figure1-1.Multipleviewsofasingledocument


Althoughmanyweb-developmentframeworksoffertheability
tocreatesitesinamodularfashionthroughreusable
components,mostfocuslargelyonautomatingredundancy
throughtheinclusionofcommoncontentblocksanduseof
codemacros.Thesesystemsrecognizethevalueofseparating
contentfromlogic,buttheyaretypicallydesignedtoconstruct
documentsinonlyonetargetformat.Thatis,thetemplates,
widgets,andcontent(orcontent-generatingcode)areall
focusedonconstructingasinglekindofdocument(usually
HTML).Renderingthesamecontentinmultipleformatsis
cumbersomeandoftenrequiressomuchduplicationatthe
componentlevelthatmodularitybecomesmoreburdenthan
blessing.Onetechnology,however,isfirmlyrootedintheideas
ofgeneratingcontext-specificrepresentationsofrichcontent
sourcesthroughbothmodularconstructionanddata
transformationthattechnologyisXML.
Thisiswherethesubjectofthisbook,AxKit,comesin.Asan
XMLpublishingandapplicationserver,AxKitbeginswithXML's
high-levelnotionofreusablecontentandseekstosimplifythe
tasksassociatedwithcreatingdynamic,context-sensitive
representationsfromrichXMLsources.Thatis,thefactthat


youneedtodeliverthesamecontentinavarietyofwaysisa
given,andpartofwhatAxKitdoesistoprovideaframeworkto
ensurethatthecorecontentistransformedcorrectlyforthe
givensituation.


1.1ExplodingaFewMythsAboutXML
Publishing
XMLanditsassociatedtechnologieshavegeneratedenormous
interest.XMLpunditsdescribeinfloridtermshowmovingto
XMListhefirststeptowardaUtopiannewWeb,whilewellfundedmarketingdepartmentschurnoutpageafterpageof
ambiguousdoublespeakabouthowusingXMListhecurefor
everythingfromlowvisitortraffictomale-patternbaldness.
Whileyoumayadmirevisionaryzealontheonehandand
understandthesimpledesiretogeneratenewbusinessonthe
other,theunfortunateresultisthatmanywebdevelopersare
confusedaboutwhatXMLisandwhatitisgoodfor.Here,I
clearupafewofthemorecommonfallaciesaboutXMLandits
useasaweb-publishingtechnology.

UsingXMLmeanshavingtomemorizeapileofcomplex
specifications.
Thereiscertainlynoshortageofspecifications,
recommendations,orwhitepapersthatdescribeorrelateto
XMLtechnologies.Developingevenacursoryfamiliarity
withthemallwouldbeafull-timejob.Thefactis,though,
thatmanyofthesespecificationsonlydescribeasingle
applicationofXML.Unlessthattoolsolvesaspecificexisting
need,there'snoreasonforadevelopertotrytouseit,
especiallyifyoucometoXMLfromanHTMLbackground.A
generalintroductiontoXML'sbasicrules,andperhapsa
quicktutorialortwothatcoversXSLToranother
transformativetool,areallyouneedtobeproductivewith
XMLandatoolsuchasAxKit.Besane.Takeapragmatic
approach:learnonlywhatyouneedtodeliveronthe
requirementsathand.


MovingtoXMLmeansthrowingawayallthetoolsand
techniquesthatIhavelearnedthusfar.
XMLissimplyawaytocapturedata,nothingmore.Notool
isappropriateforallcases,andknowinghowtouseXML
effectivelysimplyaddsanothertooltoyourbagoftricks.
Additionally(asyouwillseeinChapter9),manytoolsyou
maybeusingtodaycanbeintegratedseamlesslyinto
AxKit'sframework.Youcankeepdoingwhatworkedwellin
thepastwhiletakingadvantageofwhatAxKitmayofferin
thewayofadditionalfeatures.

XMListotallyrevolutionaryandwillsolveallofmypublishing
problems.
Thisistheoppositeofthepreviousmythbutjustas
common.Despiteconsiderablepropagandatothecontrary,
XMLoffersnothingmorethanawaytorepresent
information.Initself,XMLdoesnotaddresstheissuesof
archiving,informationretrieval,indexing,administration,or
anyothertasksassociatedwithpublishingdocuments.It
maymakefindingorbuildingtoolstoperformthesetasks
simpler,faster,morestraightforward,orlessadhoc,butno
magicisinvolved.

XMLisusefulonlyfortransferringdatastructuresamongweb
services.
Twopopularexchangeprotocols,SOAPandXML-RPC,use
XMLtocapturedata,butsuggestingthatthisistheonly
legitimateuseforXMLissimplywrong.Infact,XMLwas
originallyintendedprimarilyasapublishingtechnology.


ToolssuchasSOAPonlyemergedlaterwhenitwas
discoveredthatXMLwasquitehandyforcapturingcomplex
datainawaythatcommonprogramminglanguagescould
share.TosaythatXMLisonlyusefulfortransferringdata
betweenapplicationsisabitlikesayingthattheASCIItext
formatisonlyusefulforcomposingemailmessagespopular,
yes;exclusive,no.

Myprojectonlyrequiresdocumentstobeavailabletoweb
browsersasHTML;usingXMLwouldaddcomplexityand
overheadwithoutaddingvalue.
Itistrueneedingtodeliverthesamecontenttodifferent
targetclientsisacompellingreasontoconsiderXML
publishing,butitiscertainlynottheonlyone.Separating
thecontentfromitspresentationalsoprovidestheabilityto
fundamentallyalterthelookandfeelofanentiresite
withoutworryingabouttheinformationbeing
communicatedgettingclobberedinthebargain.Similarly,
newsitedesignprototypescanbecreatedusingtheactual
contentthatwillbedeliveredinproductionratherthanthe
boilerplatefillerthatsooftenonlyfavorsthedesigners'
senseofaesthetics.
Asforperformance,trueXMLpublishingframeworkssuchas
AxKitoffertheabilitytocachetransformedcontentevenseveral
viewsofthesamedocumentandwillonlyreprocesswheneither
thesourceXMLorthestylesheetsbeingappliedaremodified
(orwhenexplicitlyconfigured,reprocessforeachrequest).The
latestdataavailableshowsthatAxKitcandelivercached,
transformedcontentatroughly90%ofthespeed(requestsper
second)offeredbyservingthesamecontentasstaticHTML.


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