Transcript Agenda - Apache Wicket

Cost Benefit
Open Source Solutions
Introduction to
By Eyal Golan – Senior Java Consultant @ Tikal Knowledge
“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
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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
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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.
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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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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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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
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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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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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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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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Hello World – The Short Example
Put it in
your Java
add(new Label("message", "Hello World!"));
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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
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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>
Et Voila
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Add it to your
HTML
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.
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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
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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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Components Tree Hierarchy
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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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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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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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Component – AjaxLink Example
<a href=”#” wicket:id=“link”>Click</a>
The same as
regular Link
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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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
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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
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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
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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
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Wicket’s Features – The Short List
 Automatic State (no HttpSession)
 POJO for logic
» Reusability
 No XML, no configuration files
 Like Swing
 Simplicity
 Active community
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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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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
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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.html
 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
» http://www.google.com/ig/add?feedurl=http%3A%2F%2Fpipes.yahoo.com%2F
pipes%2Fpipe.run%3F_id%3Dff2c46188493fc387b9b29d93ff77078%26_rend
er%3Drss
 Wicket W. Warrick
» http://en.wikipedia.org/wiki/Wicket_W._Warrick
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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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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
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Q&A
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Thank You
[email protected]
[email protected]
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