Wicket Deliver Your Webapp On Time

Apache Wicket
Deliver your web
application on time
Yoav Hakman
Development Manager
& Consultant, AlphaCSP

2
Copyright AlphaCSP Israel 2007 The JavaEdge Seminar

Agenda

 Overview

 The Wicket Way (Concepts)

 Features

 Demo
 A wicket application
 A custom component

 Q & A

3

From Roi’s JSF presentation:

JSF 1.2 (JSR 252):
 Shortcomings
 Development
 Customizing components is complicated
 Exceptions are not descriptive
 No support for annotations
 Deployment
 Unnecessary deployment step
 Not JEE compliant (packaging, DI)
 Components
 Missing components
 Limited component functionality (DataGrid)
 Security
 No security model (managed beans, resources)
 Ajax
4

Overview
• Component based Java web framework
• rich component suite
• Open source (Apache 2 Licensed)
• Wicket makes developing webapps simple and
enjoyable again
Flat learning curve
•
No XML configuration files
•
Very easy to create and reuse components!
•
Pure Object Oriented!
•

5

A little bit of history

1.2
0.9 1.0 1.1 1.3

10/2004 10/2005 07/2007

06/2005 05/2006 11/2007

6

Good Documentation

Wicket wiki:
http://cwiki.apache.org/WICKET/

Wicket Examples (Live Demo + sources):
http://www.wicketstuff.org/wicket13/
7

JSF 2.0 (JSR 314):
 Purpose
Max. development productivity (IDE)

Min. maintenance complexity

Integrate with other web tech.

More responsive UI (Ajax)

 Requirements
Ease of development

New Features & Fixes

Performance & Scalability

Technology Adoption

8

Agenda

 Overview


 Features

 Demo

 Q & A

9

Wicket Templates

• HTML Templates contains
• static presentation code (markup)
• wicket:id attribute placeholder for wicket
components

• Forces the developer to keep “clean templates”

• The html designer has no knowledge regarding
the business domain objects
• vs jsf backing bean

10

Templates
<table>
JSP:    <tr>
    <c:forEach var=quot;itemquot; items=quot;${sessionScope.list}quot;>
      <td>
        <c:out value=quot;item.namequot; />
      </td>
    </c:forEach>
  </tr>
</table>

<h:dataTable value=quot;#{list}quot; var=quot;itemquot;>
JSF:     <h:column>
        <h:outputText value=quot;#{item.name}quot;/>
    </h:column>
</h:dataTable>

<table>
  <tr>
WICKET:     <td wicket:id=”list”>
       <span wicket:id=”name”>power point</span>
    </td>
  </tr>
</table>

11

Wicket Templates

• Most existing frameworks require special
HTML code.
• fully compliant with the XHTML standard,
so you can use:
• Macromedia Dreamweaver
• Microsoft Front Page
• Any other HTML editor

12

If you know Java and HTML you already know a
lot about Wicket!!

13

Linking Java and HTML

public class HelloWorld extends WebPage {

    public HelloWorld() {
        add(new Label(quot;messagequot;, quot;Hello World!quot;));
    }
}

Identifier Model

<html>
<body>
    <span wicket:id=quot;messagequot; id=quot;messagequot;>to be replaced</span>
</body>
</html>

14

Linking Java and HTML

HTML and Java files resides in the same
classpath package

15

Object Oriented

• Object Oriented
• Great for Java developers
• Everything is done in Java
• Swing like programming …

Form form = new Form(quot;customerformquot;,
new CompoundPropertyModel(new Customer()));
TextField zipCodeComponent = new TextField(quot;zipquot;);
zipCodeComponent.add(new ZipCodeValidator());
form.add(zipCodeComponent);

16

Application Class
public class DemoApplication extends WebApplication {

    @Override public Class getHomePage() {
        return HomePage.class;
    }

    @Override protected void init() {
        getMarkupSettings().setCompressWhitespace(false);
    }

• Settings
Application Settings
–
Debug Settings
–
Exception Settings
–
Markup Settings
–
Page Settings
–
RequestCycle Settings
–
Security Settings
–
Session Settings
–
18

Application Class

• The only xml configuration is the web.xml configuration!

<filter>
    <filtername>DemoApplication</filtername>
    <filterclass>org.apache.wicket.protocol.http.WicketFilter</filter
    <initparam>
        <paramname>applicationClassName</paramname>
        <paramvalue>com.alphacsp.DemoApplication</paramvalue>
    </initparam>
    <initparam>
        <paramname>configuration</paramname>
        <paramvalue>development</paramvalue>
        <! <paramvalue>deployment</paramvalue> >
    </initparam>
</filter>

19


JSF 1.2 (JSR 252):
 Shortcomings
 Development
 Deployment
 Components
 Security

20

Customizing Components

• Object Oriented Basics – how to extend:
• By Inheritance
• By Delegation
public class PasswordTextField extends TextField {

    public PasswordTextField(String id) {
        super(id);
    }

    /**
     * Processes the component tag
     */
    protected final void onComponentTag(final ComponentTag tag) {
        super.onComponentTag(tag);
        tag.put(quot;valuequot;, quot;quot;);
    }

}

21


Component Hook Methods
public class MyComponent extends Component {

    protected void onAfterRender() {
    }

    protected void onBeforeRender() {
    }

    protected void onComponentTag(ComponentTag tag) {
    }

    protected void onComponentTagBody(MarkupStream markupStream, ComponentTag openTag)
    }

    protected void onModelChanged() {
    }

    protected void onRender(MarkupStream markupStream) {

    }
}

22


• Object Oriented Basics – how to extend:
• By Inheritance
• By Delegation

23


public class SimpleAttributeModifier extends AbstractBehavior {
    /**
     * Called any time a component that has this behavior registered is
     * rendering the component tag.
     */
    public void onComponentTag(final Component component,
                               final ComponentTag tag)
{
if (isEnabled(component))
{
tag.getAttributes().put(attribute, value);
}
}

24


SimpleAttributeModifer
TextField myText = new TextField(quot;myTextquot;, new Model(quot;fooquot;));
myText.add(new SimpleAttributeModifier(quot;classquot;, quot;greenquot;));

With the following markup:

<input type=quot;textquot; wicket:id=quot;myTextquot;/>

Would be rendered as:

<input type=”text” wicket:id=”myText” name=”myText” class=”green”
value=”foo”/>

25


item.add(new AbstractBehavior() {
  /**
   * Called any time a component that has this behavior registered is
   * rendering the component tag.
   */
  public void onComponentTag(Component component, ComponentTag tag) {
    String css = (((Item) component).getIndex() % 2 == 0) ? quot;evenquot;:quot;oddquot;;
    tag.put(quot;classquot;, css);
  }
});

Output:
<tr class=“odd”>…</tr>
<tr class=“even”>…</tr>

26


• Behaviors are used for:
• Modifying attributes
• Adding Java Script events
• Adding Ajax Events

TextField field = new TextField(quot;textfieldquot;, inputModel);
add(field);

field.add(new AjaxFormComponentUpdatingBehavior(quot;onblurquot;) {
    protected void onUpdate(AjaxRequestTarget target) {
    // do something here
    }
});

27

Agenda

 Overview


 Features

 Demo

 Q & A

28


JSF 1.2 (JSR 252):
 Shortcomings
 Development
 Deployment

 Components
Security


29

Editable table

30

Table

31

Editable Tree Table

32

DatePicker

33

Captcha

34

Modal Window

35

File Upload

36

Tabbed Panel

<span wicket:id=quot;tabsquot;
   class=quot;tabpanelquot;>[tabbed panel]</span>
        List<ITab> tabs = new ArrayList<ITab>();
        tabs.add(new AbstractTab(new Model(quot;first tabquot;)) {
            public Panel getPanel(String panelId) {
                return new TabPanel1(panelId);
            }
        });
        tabs.add(new AbstractTab(new Model(quot;second tabquot;)) {
            }
        });
        tabs.add(new AbstractTab(new Model(quot;third tabquot;)) {
            }
        });
37
        add(new TabbedPanel(quot;tabsquot;, tabs));

Auto Complete Component

38

Models

• Holds the values of the components
• Mediate between the view and domain
layer

public interface IModel {

Object getObject();

void setObject(Object object);

}

39

Models

        add(new Label(quot;messagequot;, quot;Hello World!quot;));
    }
}


        add(new Label(quot;messagequot;, new Model(quot;Hello World!quot;));
    }
}

The data is constant

40

Models


        add(new TextField(quot;namequot;, new Model(person.getName()));
    }
}

• Immutable, not dynamic
• Can produce null pointer exceptions!
person.getAddress().getCity()

41

Models

personForm.add(new TextField(quot;personNamequot;, new IModel() {
            public Object getObject() {
                return person.getName();
            }

            public void setObject(Serializable serializable) {
                person.setName((String) serializable);
            }
        }));

• Dynamic
• Inconvenient!

42

Models

new TextField(quot;personNamequot;, new PropertyModel(person, quot;namequot;));

• The expression language is more compact
than the analogous Java code
• Simpler than to subclass a Model
• No null pointer exceptions
– “person.address.city”

43

Models

Model Description
Model Wraps a serializable object
PropertyModel Uses a property expression to
dynamically access a property in
your domain objects
CompoundPropertyModel Uses component identidiers as
property expressions

LoadableDetachableModel Used for large data sets
ResourceModel Used for retrieving messages from
resource bundles
StringResourceModel Adds property expressions and
MessageFormat substitutions
44


JSF 1.2 (JSR 252):
 Shortcomings
 Development
 Deployment
 Components
 Security

45

descriptive exceptions!

46

More Features

• Ajax Debug Window
– Shows the ajax request and response
– Shows exceptions
• Integration with other frameworks
Spring
•
Juice
•
Seam 2.0
•
Acegi Security
•
• Nice and Secure URL’s

47

Sessions

• Strongly Typed Sessions

public class MySession extends WebSession {
   private String myAttribute;
   private ShoppingCart cart;
   private UserDetails userDetails;

   public MySession(WebApplication application) {
      super(application);
   }
   // ... getters and setters
}

48

Localization

String Resource Search Order:
•
Component
•
Panel (parent)
•
Page
•
Application
•

49

Agenda

 Overview


 Features

 Demo

 Q & A

50

Q&A
51

Wicket Deliver Your Webapp On Time

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