Slide 1: Cost Benefit Open Source Solutions
Introduction to
By Eyal Golan – Senior Java Consultant @ Tikal Knowledge
Slide 2: “Apache Wicket is a component oriented Java web application framework. With proper mark-up/logic separation, a POJO data model, and a refreshing lack of XML, Apache Wicket makes developing web-apps simple and enjoyable again. Swap the boilerplate, complex debugging and brittle code for powerful, reusable components written with plain Java and HTML.*”
*The Wicket Team
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 3: Introduction to Wicket - Agenda
What is Wicket?
» Wicket in a Nutshell » Stateful, Just Java, Just HTML
Wicket Architecture The component concept Getting Wicket Wicket’s Features Wicket on the web Q&A
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 4: Wicket in a Nutshell
“A Java software framework to enable component oriented, programmatic manipulation of markup.” (WIA)
» Manipulation of markup – Use Wicket to manipulate the markup tags and their contents. (<span>[content]</span>) » Programmatic manipulation – Wicket forces a strict separation of presentation and logic. Java is used to derive the dynamic parts of the markup templates. » Component Oriented – The application is constructed of reusable components. The components have their own states and behaviors. It is very similar to programming with Swing / SWT.
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 5: Wicket is stateful
Wicket is a stateful framework.
» Wicket was developed to solve the problems that REST introduced to web applications development
• Security, modularization, state maintenance and everything as Strings
» No need to decide how to pass state
• Wicket manages state transparently
» Wicket hides the fact that you work on a stateless protocol
• Feels like regular Java programming
The state of components is managed for you.
» public class EditBarLink extends Link {
private final Person person; public EditBarLink(String id, Person person) { super(id); this.person = person; } public void onClick() { setResponsePage(new EditPersonPage(person)); } }
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Slide 6: Just Java
You decide how components are created, assembled and combined and - to some extend – what their life cycle looks like
» The developer is in charge of how the components are created
• Constructor, inheritance etc.
» Component classes can be designed in any way
• Class members, hierarchy etc.
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Slide 7: Just HTML
Just HTML
» Presentation is defined in HTML markups » HTML templates you use with Wicket only contain static presentation code (markup) and placeholders where Java components are hooked in
• There is never logic in the templates
» You pretty much have to know the structure of your page* upfront
• * Or any other component that has a corresponding markup (Page, Panel, Border and Fragment). This will be explained later • * The pieces can be put together dynamically
» <tr>
<td wicket:id=”list”> <span wicket:id=”name” /> </td> </tr>
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Dynamic Table
Slide 8: Introduction to Wicket - Agenda
What is Wicket? Wicket Architecture / behind the scene
» A brief explanation
The component concept Getting Wicket Wicket’s Features Wicket on the web Q&A
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Slide 9: Wicket Architecture
In this section we will go over the main role players of a Wicket application
» This is only a brief introduction » The section is intended only to be familiarized with the primary classes that create a Wicket application
Application
» One object instance for an application » Bundles all components, markups, properties, settings files etc. » Acts as the central hub of processing » The Application object is used for customize the application’s behavior
Session
» Holds the state of one user » Wicket allows to have custom session » With a custom session we know exactly what can be store in a session
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Slide 10: Wicket Architecture (cont.)
RequestCycle
» Responsible of processing requests » Uses Request and Response objects
Some examples of Application Customization
» A SecuredSession that allows only logged in user to open a certain page » How to render a disabled link » How to mount pages with a nice readable URL
Component
» Page, Form, Label, TextField, DropDown, WebMarkupContainer and much more
Model
» The Model is an indirection for how to get the data that drives the Java components. Models hide ‘what’ data to get and ‘from where’ to get it, and Java components hide ‘when’ and ‘how’ that data is displayed
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Slide 11: Introduction to Wicket - Agenda
What is Wicket? Wicket Architecture The component concept
» Hello World… The shortest example ever! » Component – The building block
• A few examples
Getting Wicket Wicket’s Features Wicket on the web Q&A
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Slide 12: Hello World – The Short Example
Put it in your Java add(new Label("message", "Hello World!"));
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Slide 13: Hello World – The Short Example
Put it in your Java add(new Label("message", "Hello World!")); + <h1 wicket:id=“message”>[text goes here]</h1> Add it to your HTML
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 14: Hello World – The Short Example
Put it in your Java add(new Label("message", "Hello World!")); + <h1 wicket:id=“message”>[text goes here]</h1> = <h1>Hello World!</h1> Add it to your HTML
Et Voila
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 15: What about picking a date?
DateTextField dateTxt = new DateTextField("dateTxt"); dateTxt.add(new DatePicker()); add(dateTxt); <input wicket:id=“dateTxt”></input> You can manipulate the header by adding calls to CSS and JS files.
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 16: Introduction to Wicket - Agenda
What is Wicket? Wicket Architecture The component concept
» Hello World… The shortest example ever! » Component – The building block
Getting Wicket Wicket’s Features Wicket on the web Q&A
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 17: About Components
“Apache Wicket is a component oriented …”
» Components are the building blocks of Wicket
They are self contained and do not leak scope
» Other components don’t have to know about it
They are reusable You build them using plain Java
» You use them using plain Java
Components can be nested to “components tree”
» Each component that is added in the Java file must be added in the same hierarchy in the corresponding HTML file » Pages are special components that function as the root for such trees
The components are the objects that encapsulate the manipulation the markup Their data is separated using the IModel interface
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Slide 18: Components Tree Hierarchy
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Slide 19: Component + Markup
Component has wicket id Markup has the same wicket:id Hierarchy must much
Java Code
Link link = new Link(“link”) {…} add(link); link.add(new Label("message", “My Message")); <a href=”#” wicket:id=“link”> <span wicket:id=“message”>[text replaced]</span> </a> HTML Code
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Slide 20: Component + Markup
Some components have a markup file associated with them and others don’t Components with an associated markup
» Page, Panel, Border, Fragment » Both files should reside in the same package folder*, and should have the same name
• src/com/tikal/presentation/HelloWorldPage.java • src/com/tikal/presentation/HelloWorldPage.html • *And naturally Wicket allows to configure this behavior
Some components without an associated markup
» The markup for this components are located in their parent XXX.html » Label, Button, DropDown, Link, Form and more
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Slide 21: Component – Link Example
HTML Code
<a href=”#” wicket:id=“link”>Click</a> Link link = new Link("link") { … @Override public void onClick() { setResponsePage(OrdersReportsPage.class); } });
Java Code
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Slide 22: Component – AjaxLink Example
The same as regular Link
<a href=”#” wicket:id=“link”>Click</a>
someComponent.setOutputMarkupId(true); AjaxLink link = new AjaxLink("link") { private static final long serialVersionUID = 1L; @Override public void onClick(AjaxRequestTarget target) { // Do Something target.addComponent(someComponent); target.appendJavaScript(“Effects.fade(‘foo’)”); } });
Some Ajax stuff in Java
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Slide 23: Just Java + Just HTML (returned)
The designer creates the page with his favorite designing tool The Wicket programmer adds wicket:id as a hook in the file Minor issue – If the HTML hierarchy changes, it should be changed in the Java code as well
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 24: Introduction to Wicket - Agenda
What is Wicket? Wicket Architecture The component concept Getting Wicket (So easy…)
» Starting point for Wicket
Wicket’s Features Wicket on the web Q&A
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 25: Getting Wicket
A great quick start in Wicket’s site
» http://wicket.apache.org/quickstart.html » Create a maven archetype to work with » Run
• mvn jetty:run • Use the Start.java class that is created automatically • Create a war file and put in a web server (or an application server)
A quick start project that builds your own Wicket project
» http://www.antwerkz.com/qwicket/app/home
• A bit tricky to start with it
Wiki getting started
» http://cwiki.apache.org/WICKET/newuserguide.html
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 26: Introduction to Wicket - Agenda
What is Wicket? Wicket Architecture The component concept Getting Wicket Wicket’s Features
» A list of (most) features
Wicket on the web Q&A
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 27: Wicket’s Features – The Short List
Automatic State (no HttpSession) POJO for logic
» Reusability
No XML, no configuration files Like Swing Simplicity Active community
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 28: Wicket’s Features – The Long List
Clean / clear separation of presentation and logic POJO for logic No XML, no configuration files Security i18n Built-in Ajax without the need to write JavaScript Transparent state and session management
» Stateful » Navigation history, support of multiple tabs/windows in the browser
Markup inheritance (OOD) Has validation Integrating with other frameworks (Spring, Hibernate) Has Lazy Loading facilities Active community
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Copyright 2007 Tikal Knowledge, Ltd.
Slide 29: Introduction to Wicket - Agenda
What is Wicket? Wicket Architecture The component concept Getting Wicket Wicket’s Features Wicket on the web
» Some useful links
Q&A
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 30: Wicket on the Web
Home of Wicket
» http://wicket.apache.org/index.html
Wicket-extension (expansion of Wicket)
» http://wicket.apache.org/docs/wicket-1.3.2/wicket-extensions/index.htm
Wicket Forums
» http://www.nabble.com/Apache-Wicket-f13974.html
Wicketstuff (cool libraries for Wicket)
» http://wicketstuff.org/confluence/display/STUFFWEB/Home » http://wicketstuff.org/wicket13/ (examples)
InMethod (Wicket table component)
» http://inmethod.com/
Wicket Blogs Wicket W. Warrick » http://en.wikipedia.org/wiki/Wicket_W._Warrick
» http://www.google.com/ig/add?feedurl=http%3A%2F%2Fpipes.yahoo.co
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 31: Wicket on the Books
Wicket In Action
» Martijn Dashorst, Eelco Hillenius » http://wicketinaction.com/ » http://manning.com/dashorst/
Pro Wicket
» Karthik Gurumurthy » http://www.apress.com/book/view/1590597222
Enjoying Web Development with Wicket
» Kent Tong » http://www.agileskills2.org/EWDW/
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Slide 32: Copyright 2007 Tikal Knowledge, Ltd.
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Slide 33: Summary
Wicket is cool and fun Wicket gives an easy and fast Web Application development Has a very clear OOD approach Lets the user concentrate on the business logic The community is very dynamic and helpful Wicket is a dynamic framework that is built upon users’ request and suggestion
» Last Stable version 1.3.4 » Wicket 1.4-M3 is the next version to go out
Copyright 2007 Tikal Knowledge, Ltd.
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Slide 34: Q&A
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Slide 35: Thank You
egolan@tikalk.com egolan74@gmail.com
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