GeLiftete Web-Applikation mit Scala - Tobias Joch - inovex GmbH

GeLiftete Web-Applikation mit Scala JAX 2009 Tobias Joch inovex GmbH Wir nutzen Technologien, um unsere Kunden glücklich zu machen. Und uns selbst.

Scala Lift Grundlagen Architektur Überblick Module Template Verarbeitung Tags und Snippets Head Merge Scopes I18n Persistenz AJAX in Action Fazit / Ausblick / weiterführende Informationen 2

Scala = SCAlable LAnguage 4

Scala = SCAlable LAnguage wächst mit den Bedürfnissen der User kleine Skripte bis hin zu großen und komplexen Systemen Multiparadigmensprache verbindet objektorientierte (imperative) und funktionale Programmierung pragmatisch, typsicher, strikt objektorientiert interoperabel mit Standard Plattformen (Java, .NET) 4

Wurzeln reichen zurück in das Jahr 1995 Philip Wadler und Martin Odersky Funktionale Programmiersprachen für die JVM Pizza GJ (Generic Language Extension für Java) javac Java Generics 1999 verfolgte Martin Odersky das Ziel funktionale mit OO Programmierung zu kombinieren Funnel Scala *2001, 2003 erstes Public Release, 2006 Version 2.0, aktuell 2.7.4 RC1 5

Ziel von Scala: Das Beste aus beiden Welten (OO und FP) Statisch typisiert + Typinferenz Funktionen höherer Ordnung Traits, Mixin-Komposition Option-Klasse (None und Some vs. null) Pattern Matching Algebraische Typen Native XML-Unterstützung inkl. XPath Unterstützung (Bibliothek) Actor Model Currying Anonyme Funktionen Parametrische Polymorphie 6

Einige reservierte Schlüsselwörter in Scala class, case class, object new with extends abstract sealed trait def, var, val override match, case 7

in Action ;) 8

Scala Shell Interactive Ruby Shell (IRB) ./scala Optimal für schnelle Tests 9

Imperative vs. funktionale Programmierung (I) public class Example1 { public static void main(String[] args) { for (String arg : args) { System.out.println(arg); } } } 10

Imperative vs. funktionale Programmierung (I) public class Example1 { public static void main(String[] args) { for (String arg : args) { System.out.println(arg); } } } object Example1 { def main(args: Array[String]) { args.foreach(println) } } 10

Imperative vs. funktionale Programmierung (II) public class Example2 { public static void main(String[] args) { for (String arg : args) { if (arg.startsWith(quot;JAX09quot;)) { System.out.println(arg); } } } } 11

Imperative vs. funktionale Programmierung (II) public class Example2 { public static void main(String[] args) { for (String arg : args) { if (arg.startsWith(quot;JAX09quot;)) { System.out.println(arg); } } } } object Example2 { def main(args: Array[String]) { args.filter(_.startsWith(quot;JAX09quot;)).foreach(println) } } 11

Imperative vs. funktionale Programmierung (III) public class Example3 { public static void main(String[] args) { boolean exists = false; for (String arg : args) { if (arg.startsWith(quot;JAX09quot;)) { exists = true; break; } } System.out.print(exists); } } 12

Imperative vs. funktionale Programmierung (III) public class Example3 { public static void main(String[] args) { boolean exists = false; for (String arg : args) { if (arg.startsWith(quot;JAX09quot;)) { exists = true; break; } } System.out.print(exists); } } object Example3 { def main(args: Array[String]) { print(args.exists(_.startsWith(quot;JAX09quot;))) } } 12

Grundlagen 13

David Pollak Gründer von Lift Kommerzielle Softwareentwicklung seit 1977 Web-Applikationen seit 1996 15. Februar 2007: Initial Import (GitHub) in der Version 0.1.0 Gründung von Lift als OS Projekt in 2007 26. Februar 2009: Lift 1.0 Aktuelles Lift-Team besteht aus 13 Comitter Aktive Community http://groups.google.com/group/liftweb 14

„Best of all“ Scala als zugrundeliegende Sprache nativer XML-Support (XHTML nativ innerhalb von Snippets!) Scala Actors für mächtige Comet-Anwendungen fein granulare Sessions und Security (Seaside) schnelles Projektsetup durch „convention over configuration“ + geringe Turnaround-Zeiten (Rails) Django's quot;more than just CRUD is includedquot; Designer freundliche Templates (Wicket / Lift View First) Offen für die Nutzung von zahlreichen OSS-Bibliotheken (Java) Etablierte Deployment-Prozesse (JEE / Java) 15

Weitere Eigenschaften / Ziele von Lift Sicherheit XSS, replay Attacken, Parameter tampering Wartbarkeit Skalierbarkeit Performance Hohe Produktivität Einfach Convention over configuration DRY 16

„View First“ Design-Prinzip Templates enthalten keinen Code Pures XHTML Können mit Standard Design-Werkzeugen bearbeitet werden Frontend ist ohne Scala-Kenntnisse von einem Designer realisierbar <lift:surround with=quot;defaultquot; at=quot;contentquot;> <h2>Welcome to your project!</h2> <p><lift:helloWorld.howdy /></p> </lift:surround> 17

Architektur Überblick 18

Lift-Framework 19

Lift-Framework Scala Framework 19

Lift-Framework Lift-Framework Scala Framework 19

Lift-Framework Lift Core Lift-Framework Scala Framework 19

LiftSession LiftRules LiftResponse Lift-Framework S SHtml JS API Lift Core Lift Webkit SiteMap Menu, Msgs, Lift-Framework Scala Framework CSS HTTP Auth Comet 19

LiftSession LiftRules Mapper LiftResponse Lift-Framework S SHtml Record JS API Lift Core Lift Webkit SiteMap Menu, Msgs, Lift-Framework Scala Framework CSS HTTP Auth Comet 19

Lift-Framework Mapper Record Testkit LiftResponse Menu, Msgs, LiftSession HTTP Auth LiftRules SiteMap JS API SHtml Comet CSS S Lift Webkit Lift Core Lift-Framework Scala Framework 19

Lift-Framework Mapper Record Testkit LiftResponse Menu, Msgs, LiftSession HTTP Auth LiftRules SiteMap JS API SHtml Comet CSS S Lift Webkit Lift Util Lift Core Lift-Framework Scala Framework 19

Lift-Framework Lift XMPP Mapper Record Testkit Lift Facebook LiftResponse Menu, Msgs, LiftSession HTTP Auth Lift Widgets LiftRules SiteMap JS API SHtml Comet CSS S Lift OpenId Lift OAuth Lift Webkit Lift Paypal Lift Util Lift AMQP Lift Core Lift-Framework Scala Framework 19

Grobe Architektur einer Lift-Applikation 20

Grobe Architektur einer Lift-Applikation Java Virtual Machine 20

Grobe Architektur einer Lift-Applikation Servlet Container (e.g. Jetty or Tomcat) Java Virtual Machine 20

Grobe Architektur einer Lift-Applikation Lift Framework Servlet Container (e.g. Jetty or Tomcat) Java Virtual Machine 20

Grobe Architektur einer Lift-Applikation Templates Lift Framework Servlet Container (e.g. Jetty or Tomcat) Java Virtual Machine 20

Grobe Architektur einer Lift-Applikation Templates Snippets Lift Framework Servlet Container (e.g. Jetty or Tomcat) Java Virtual Machine 20

Grobe Architektur einer Lift-Applikation Templates Snippets Views Lift Framework Servlet Container (e.g. Jetty or Tomcat) Java Virtual Machine 20

Grobe Architektur einer Lift-Applikation Templates Snippets Views Boot.scala (LiftRules etc,) Lift Framework Servlet Container (e.g. Jetty or Tomcat) Java Virtual Machine 20

Grobe Architektur einer Lift-Applikation Templates Snippets Model Views Boot.scala (LiftRules etc,) Lift Framework Servlet Container (e.g. Jetty or Tomcat) Java Virtual Machine 20

Grobe Architektur einer Lift-Applikation Templates Snippets Model LiftFilter Views Boot.scala (LiftRules etc,) Lift Framework Servlet Container (e.g. Jetty or Tomcat) Java Virtual Machine 20

Grobe Architektur einer Lift-Applikation Templates Snippets LiftServlet Model LiftFilter Views Boot.scala (LiftRules etc,) Lift Framework Servlet Container (e.g. Jetty or Tomcat) Java Virtual Machine 20

Grobe Architektur einer Lift-Applikation Templates Snippets LiftServlet Model LiftFilter Views Boot.scala (LiftRules etc,) Lift Framework DefaultServlet Servlet Container (e.g. Jetty or Tomcat) Java Virtual Machine 20

Grober Ablauf einer Anfragenbearbeitung Request URL rewrite custom dispatch Template View Response Response Response Response 21

Grober Ablauf einer Anfragenbearbeitung Template Request URL rewrite custom dispatch View Response Response Response Response 21

Template Template Verarbeitung Request Mapping nach folgendem Schema 22

Template Template Verarbeitung Request Mapping nach folgendem Schema <path>[_<language, optional>][.<suffix>] 22

Template Template Verarbeitung Request Mapping nach folgendem Schema <path>[_<language, optional>][.<suffix>] Lift wählt die passende Sprache und Endung 22

Template Template Verarbeitung Request Mapping nach folgendem Schema <path>[_<language, optional>][.<suffix>] Lift wählt die passende Sprache und Endung Links ohne Sprache und Endung angeben 22

Template Template Verarbeitung Request Mapping nach folgendem Schema <path>[_<language, optional>][.<suffix>] Lift wählt die passende Sprache und Endung Links ohne Sprache und Endung angeben Lift versteckt Templates und Ressourcen in Verzeichnissen welche als Endung -hidden im Namen tragen 22

Template 23

Template Templates = Content + Tags + Snippets 23

Template Templates = Content + Tags + Snippets Tags = Lift spezifische Funktionen surround bind embed comet loc 23

Template Templates = Content + Tags + Snippets Tags = Lift spezifische Funktionen surround bind embed comet loc Snippets vergleichbar mit Taglibs <lift:snippet type=Jax:render /> <lift:Jax.render /> <lift:Jax /> 23

› Template Template Verarbeitung von Außen nach Innen 24

› Template Template Verarbeitung von Außen nach Innen /index.html <lift:surround with=quot;defaultquot; at=quot;contentquot;> <h2>Welcome to your project!</h2> <p><lift:HelloWorld.howdy /></p> </lift:surround> 24

› Template Template Verarbeitung von Außen nach Innen /index.html <lift:surround with=quot;defaultquot; at=quot;contentquot;> <h2>Welcome to your project!</h2> <p><lift:HelloWorld.howdy /></p> </lift:surround> /templates-hidden/default.html <html xmlns=quot;...quot; xmlns:lift=quot;http://liftweb.net/quot;> <head>...</head> <body> ... <lift:bind name=quot;contentquot; /> </body> </html> 24

› Template Template Verarbeitung von Außen nach Innen /index.html <lift:surround with=quot;defaultquot; at=quot;contentquot;> <h2>Welcome to your project!</h2> <p><lift:HelloWorld.howdy /></p> </lift:surround> /templates-hidden/default.html <html xmlns=quot;...quot; xmlns:lift=quot;http://liftweb.net/quot;> <head>...</head> <body> ... <lift:bind name=quot;contentquot; /> </body> </html> Ausführung von HelloWorld#howdy 24

Template Head Merge 25

Template Head Merge /index.html <lift:surround with=quot;defaultquot; at=quot;contentquot;> <head><script type=quot;text/javascriptquot;>...</script>...</head> <h2>Welcome to your project!</h2> <p><lift:helloWorld.howdy /></p> </lift:surround> 25

Template Head Merge /index.html <lift:surround with=quot;defaultquot; at=quot;contentquot;> <head><script type=quot;text/javascriptquot;>...</script>...</head> <h2>Welcome to your project!</h2> <p><lift:helloWorld.howdy /></p> </lift:surround> /templates-hidden/default.html <html xmlns=quot;...quot; xmlns:lift=quot;http://liftweb.net/quot;> <head>...</head> <body> ... <lift:bind name=quot;contentquot; /> </body> </html> 25

Scopes S Stateful Snippet RequestVar SessionVar Scala Object (Singleton) 26

Internationalisierung / I18n java.util.Locale java.util.ResourceBundle LiftRules.resourceNames Ermittlung der aktuellen Sprache LiftRules.localeCalculator Request-Header Fallback: Locale.getDefault() Snippets S.? Templates <lift:loc locid=quot;liftquot;>Aufzug</lift:loc> <lift:loc>lift</lift:loc> 27

Persistenz in Lift Mapper Record JPA JDO Hibernate ... Lift selbst ist Persistenz agnostisch 28

AJAX in Lift SHtml ajaxButton ajaxText ajaxCheckbox ... def render(in: NodeSeq): NodeSeq = SHtml.ajaxButton(quot;Click me ;)quot;, () => { println(quot;Yes, thanks!quot;) JsCmds.SetHtml(quot;click-divquot;, Text(quot;Yes, thanks!quot;)) }) 29

in Action ;) 30

Entwicklungsumgebung Java (>= 5) Maven (>= 2.0.9) Web-Container (Jetty, Tomcat, ...) Optional, aber nützlich JavaRebel (JVM Plugin / Java Agent) IDE mit Scala Support / Plugin (Eclipse, IDEA, Netbeans, ...) http://www.scala-lang.org/scala-eclipse-plugin 31

Projekt anlegen 32

Projekt anlegen $mvn archetype:generate -U -DarchetypeGroupId=net.liftweb -DarchetypeArtifactId=lift-archetype-basic -DarchetypeVersion=1.0 -DgroupId=de.inovex.jax2009.lift -DartifactId=lift-demo 32

Projekt anlegen $mvn archetype:generate -U -DarchetypeGroupId=net.liftweb -DarchetypeArtifactId=lift-archetype-basic -DarchetypeVersion=1.0 -DgroupId=de.inovex.jax2009.lift -DartifactId=lift-demo Import in Eclipse vorbereiten $cd lift-demo && mvn eclipse:eclipse 32

Projektlayout 33

Ausführen 34

Ausführen $mvn jetty:run 34

index.html 35

index.html <lift:surround with=quot;defaultquot; at=quot;contentquot;> <h2>Welcome to your project!</h2> <p><lift:helloWorld.howdy /></p> </lift:surround> 35

index.html <lift:surround with=quot;defaultquot; at=quot;contentquot;> <h2>Welcome to your project!</h2> <p><lift:helloWorld.howdy /></p> </lift:surround> HelloWorld.scala 35

index.html <lift:surround with=quot;defaultquot; at=quot;contentquot;> <h2>Welcome to your project!</h2> <p><lift:helloWorld.howdy /></p> </lift:surround> HelloWorld.scala import java.util.Date class HelloWorld { def howdy = <span>Welcome to lift-demo at {new Date}</span> } 35

default.html 36

default.html <div class=quot;containerquot;> <div class=quot;column span-12 lastquot; style=quot;text-align: rightquot;> <h1 class=quot;altquot;>lift-demo <img id=quot;ajax-loaderquot; style=quot;display:none; margin-bottom: 0px; margin-left: 5pxquot; src=quot;/images/ajax-loader.gifquot;/></h1> </div> <hr/> <div class=quot;column span-6 colborder sidebarquot;> <hr class=quot;spacequot; /> <lift:Menu.builder /> <div> <lift:snippet type=quot;msgsquot;/> <hr class=quot;spacequot; /> </div> </div> <div class=quot;column span-17 lastquot;> <lift:bind name=quot;contentquot; /> </div> <hr /> <div class=quot;column span-23 lastquot; style=quot;text-align: centerquot;> <h4 class=quot;altquot;> <a href=quot;http://liftweb.netquot;><i>Lift</i></a> is Copyright 2007-2009 WorldWide Conferencing, LLC. Distributed under an Apache 2.0 License.</h4> </div> </div> 36

Boot.scala 37

Boot.scala def boot { if (!DB.jndiJdbcConnAvailable_?) DB.defineConnectionManager(DefaultConnectionIdentifier, DBVendor) // where to search snippet LiftRules.addToPackages(quot;de.inovex.jax2009.liftquot;) // create or update the database schema Schemifier.schemify(true, Log.infoF _, User) // build site map val entries = Menu(Loc(quot;Homequot;, List(quot;indexquot;), quot;Homequot;)) :: User.sitemap LiftRules.setSiteMap(SiteMap(entries:_*)) // Show the spinny image when an Ajax call starts LiftRules.ajaxStart = Full(() => LiftRules.jsArtifacts.show(quot;ajax-loaderquot;).cmd) // Make the spinny image go away when it ends LiftRules.ajaxEnd = Full(() => LiftRules.jsArtifacts.hide(quot;ajax-loaderquot;).cmd) // force the request to be UTF-8 LiftRules.early.append(makeUtf8) S.addAround(DB.buildLoanWrapper) 37 }

Rekursive Template Komposition 38

Rekursive Template Komposition class HelloWorld { def howdy = <span>Welcome to lift-demo at {new Date} at <lift:helloWorld.howdy2 /></span> def howdy2 = <span>JAX 2009!</span> } 38

Formulare <lift:surround with=quot;defaultquot; at=quot;contentquot;> <h2>Very first form example:</h2> <p> <lift:FormExample form=quot;POSTquot;> <f:name><input type=quot;textquot;/></f:name> <input type=quot;submitquot; value=quot;Postquot;/> </lift:FormExample> </p> </lift:surround> 39

Formulare <lift:surround with=quot;defaultquot; at=quot;contentquot;> <h2>Very first form example:</h2> <p> <lift:FormExample form=quot;POSTquot;> <f:name><input type=quot;textquot;/></f:name> <input type=quot;submitquot; value=quot;Postquot;/> </lift:FormExample> </p> </lift:surround> class FormExample { def render(xhtml: NodeSeq) = { bind(quot;fquot;, xhtml, quot;namequot; -> text(quot;quot;, println(_))) } } 39

Formulare <lift:surround with=quot;defaultquot; at=quot;contentquot;> <h2>Very first form example:</h2> <p> <lift:FormExample form=quot;POSTquot;> <f:name><input type=quot;textquot;/></f:name> <input type=quot;submitquot; value=quot;Postquot;/> </lift:FormExample> </p> </lift:surround> class FormExample { def render(xhtml: NodeSeq) = { bind(quot;fquot;, xhtml, quot;namequot; -> text(quot;quot;, println(_))) } } // in boot.scala: val entries = Menu(Loc(quot;Homequot;, List(quot;indexquot;), quot;Homequot;)) :: Menu(Loc(quot;form1quot;, List(quot;veryFirstFormquot;), quot;Examplequot;)) :: User.sitemap LiftRules.setSiteMap(SiteMap(entries:_*)) 39

Formulare 40

Formulare JAX 2009! INFO - Service request (POST) /veryFirstForm took 61 Milliseconds 40

GeLiftete Web-Applikation mit Scala - Tobias Joch - inovex GmbH

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