Apache Wicket

https://nightlies.apache.org/wicket/guide/10.x/
Admin
Apache Wicket is a Java web application framework that provides a component-based architecture for...
Tokens:74,354
Snippets:908
Trust Score:10
Update:2 months ago
Show doc for...
Tokens:
Raw
### Clone the Wicket tutorial examples repository

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Use this command to download the example code repository to your local machine.

```bash
git clone https://github.com/bitstorm/Wicket-tutorial-examples.git
```

--------------------------------

### Install Wicket feature

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Install the core Wicket feature into the Karaf environment.

```text
karaf@root()> feature:install wicket-core
```

--------------------------------

### XML Resource Bundle Example

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

An example of a properties file formatted as XML, conforming to the standard Java properties DTD.

```xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
	<entry key="greetingMessage">欢迎光临本网站！</entry>
</properties>
```

--------------------------------

### Implement InMethod DataGrid

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Illustrates the setup of a DefaultDataGrid with a ListDataProvider and column definitions.

```html
...
  <div wicket:id="grid">Grid</div>
...
```

```java
final List<Person> personList = //load a list of Persons
final ListDataProvider listDataProvider = new ListDataProvider(personList);
//define grid's columns
List<IGridColumn> cols = (List) Arrays.asList(
	     new PropertyColumn(new Model("First Name"), "firstName"),
	     new PropertyColumn(new Model("Last Name"), "lastName"));

DataGrid grid = new DefaultDataGrid("grid", new DataProviderAdapter(listDataProvider), cols);
add(grid);
```

--------------------------------

### Define Greeting Message Property

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of a default resource bundle properties file entry.

```properties
greetingMessage=Welcome to the site!
```

--------------------------------

### Localized Resource Bundles

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example property files for English, German, and Italian localization of component choices.

```properties
selectColor.null=Select a color
green=Green
red=Red
blue=Blue
yellow=Yellow
```

```properties
selectColor.null=Wählen Sie eine Farbe
green=Grün
red=Rot
blue=Blau
yellow=Gelb
```

```properties
selectColor.null=Scegli un colore
green=Verde
red=Rosso
blue=Blu
yellow=Giallo
```

--------------------------------

### Configure StringResourceModel Bundle

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example key/value pairs for a resource bundle using property expressions for dynamic content.

```properties
orderStatus.0=Your payment submitted on ${orderDate} has been accepted.
orderStatus.1=Your order submitted on ${orderDate} is in progress.
orderStatus.2=Your order submitted on ${orderStatus.2} has been shipped.
orderStatus.3=Your order submitted on ${orderDate} has been delivered.
```

--------------------------------

### Implement a Custom WebApplication Class

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of a custom application class extending WebApplication, overriding getHomePage and init methods.

```java
public class WicketApplication extends WebApplication
{
	@Override
	public Class<? extends WebPage> getHomePage()
	{
		return HomePage.class;
	}

	@Override
	public void init()
	{
		super.init();
		// add your configuration here
	}
}
```

--------------------------------

### Verify Wicket feature installation

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

List available Wicket features to confirm the repository was added correctly.

```text
karaf@root()> feature:list | grep -i wicket
wicket-core    │ _version_ │    │ Uninstalled │ org.apache.wicket.wicket-_version_ │
```

--------------------------------

### Example URL with Indexed Parameters

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

A representation of a URL containing indexed parameters and a query string.

```text
<application path>/foo/bar?1&baz=baz
```

--------------------------------

### Maven Dependencies Configuration

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of the <dependencies> section in pom.xml for managing Wicket modules.

```xml
...
<dependencies>
	<!--  WICKET DEPENDENCIES -->
	<dependency>
		<groupId>org.apache.wicket</groupId>
		<artifactId>wicket-core</artifactId>
		<version>${wicket.version}</version>
	</dependency>
	<dependency>
		<groupId>org.apache.wicket</groupId>
		<artifactId>wicket-ioc</artifactId>
		<version>${wicket.version}</version>
	</dependency>
	<!-- OPTIONAL DEPENDENCY
	<dependency>
		<groupId>org.apache.wicket</groupId>
		<artifactId>wicket-extensions</artifactId>
		<version>${wicket.version}</version>
	</dependency>
	-->
	...
</dependencies>
...
```

--------------------------------

### Queue Components in Hierarchy

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of using queueing to manage nested components within a secure container.

```java
queue(new Label("first"));
queue(new Label("last"));

WebMarkupContainer secure=new WebMarkupContainer("secure") {
    void onConfigure() {
       super.onConfigure();
       setVisible(isViewingOwnProfile());
    }
};

queue(secure);
secure.queue(new Label("creditCardNumber"));
secure.queue(new Label("creditCardExpiry"));
```

--------------------------------

### Java component hierarchy using queueing

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of using the queueing mechanism to automatically resolve component hierarchy.

```java
queue(new Form("customer"));
queue(new TextField("first"));
queue(new TextField("last"));

WebMarkupContainer child=new WebMarkupContainer("child");
queue(child);
child.queue(new TextField("first"));
child.queue(new TextField("last"));
child.queue(new TextField("dob"));
```

--------------------------------

### Implementing a custom IConverter

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example implementation of an IConverter for the java.util.regex.Pattern class.

```java
public class RegExpPatternConverter implements IConverter<Pattern> {
	@Override
	public Pattern convertToObject(String value, Locale locale) {
		return Pattern.compile(value);
	}

	@Override
	public String convertToString(Pattern value, Locale locale) {
		return value.toString();
	}
}
```

--------------------------------

### Implement HomePage with footer container

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of a page class that adds a footer container and renders JavaScript items to be handled by the decorator.

```java
   public HomePage(final PageParameters parameters) {
        super(parameters);

        add(new HeaderResponseContainer("footer-container", "footer-container"));
    }

    @Override
    public void renderHead(IHeaderResponse response) {
        response.render(JavaScriptHeaderItem.forReference(new PackageResourceReference(getClass(),
                "javascriptLibrary.js")));

        response.render(OnEventHeaderItem.forScript("'click-me'", "click", "alert('Clicked me!')"));
    }
```

--------------------------------

### Initialize and Test a Page with WicketTester

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Demonstrates the standard setup of WicketTester in a JUnit 5 test class and basic page rendering verification.

```java
class TestHomePage{
	private WicketTester tester;

	@BeforeEach
	void setUp(){
		tester = new WicketTester(new WicketApplication());
	}
	@Test
	void homepageRendersSuccessfully(){
		//start and render the test page
		tester.startPage(HomePage.class);
		//assert rendered page class
		tester.assertRenderedPage(HomePage.class);
	}
}
```

--------------------------------

### Define HomePage markup for testing

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example HTML markup used as the target for TagTester assertions.

```html
<html xmlns:wicket="http://wicket.apache.org">
	<head>
		<meta charset="utf-8" />
		<title></title>
	</head>
	<body>
		<span class="myClass"></span>
		<div class="myClass"></div>
	</body>
</html>
```

--------------------------------

### Bookmarkable URL Structure

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

An example of the URL format generated by Wicket for a bookmarkable page with parameters.

```text
<app root>/PageParametersExample/wicket/bookmarkable/
		org.wicketTutorial.PageWithParameters?foo=foo&bar=bar
```

--------------------------------

### CSS URL Transformation Examples

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Demonstrates how Wicket modifies CSS URLs for versioning or base64 embedding.

```css
...
body{
    background-image:url('../images/some.png');
}
...
```

```css
...
body{
    background-image:url('../images/some-ver-1425904170000.png');
}
...
```

```css
...
body{
    background-image: url(data:image/png;base64,R0lGODlh1wATAX....);
}
...
```

--------------------------------

### Define a Bookmarkable Page

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of a WebPage class that accepts PageParameters in its constructor to support bookmarkable URLs.

```java
public class PageWithParameters extends WebPage {
	//Override superclass constructor
	public PageWithParameters(PageParameters parameters) {
		super(parameters);
	}
 }
```

--------------------------------

### Markup with external stylesheet

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of a component including a stylesheet directly from the markup, which requires whitelisting or moving to a header contribution.

```xml
<?xml version="1.0" encoding="UTF-8"?>
<html xmlns:wicket="http://wicket.apache.org">
<head>
  <link rel="stylesheet"
    href="https://maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css" />
</head>
<body>...</body>
</html>
```

--------------------------------

### Flat Java Hierarchy Attempt

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

An example of how one might intuitively want to add components without explicit hierarchy, which causes issues with ID uniqueness and state management.

```java
add(new Form<Void>("customer"));
add(new TextField("first"));
add(new TextField("last"));
WebMarkupContainer child=new WebMarkupContainer("child");
add(child);
add(new TextField("first"));
add(new TextField("last"));
add(new TextField("dob"));
```

--------------------------------

### Set Wicket deployment mode via system property

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Pass the wicket.configuration system property during server startup via the command line.

```bash
java -Dwicket.configuration=deployment ...
```

--------------------------------

### Navigate to a Bookmarkable Page with Parameters

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Shows how to instantiate a link that navigates to a target page while passing PageParameters.

```java
add(new Link<Void>("pageWithIndexParam") {

	@Override
	public void onClick() {

		PageParameters pageParameters = new PageParameters();
		pageParameters.add("foo", "foo");
		pageParameters.add("bar", "bar");

		setResponsePage(PageWithParameters.class, pageParameters);
	}

});
```

--------------------------------

### HTML Video Component

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Markup for the video component referenced in the Java NIO example.

```html
<video wicket:id="video"/>
```

--------------------------------

### Nested forms structure

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of nesting multiple form components within each other in Wicket markup.

```html
<form wicket:id="outerForm">
	...
	<form wicket:id="innerForm">
		...
		<form wicket:id="veryInnerForm">
			...
		</form>
	</form>
</form>
```

--------------------------------

### Initialize WebMarkupContainer in Java

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Java code to instantiate and manage the visibility of a WebMarkupContainer.

```java
//Page initialization code
WebMarkupContainer informationBox = new WebMarkupContainer ("informationBox");
informationBox.add(new Label("messagesNumber", messagesNumber));
add(informationBox);

//If there are no new messages, hide informationBox
informationBox.setVisible(false);
```

--------------------------------

### Create a Model using Factory Methods

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Comparison between manual instantiation and using the Model.of factory method.

```java
new Model<String>("Hello WicketWorld!")
```

```java
Model.of("Hello WicketWorld!")
```

--------------------------------

### Initialize ResourceModel

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Create a ResourceModel to retrieve a string resource by key, optionally providing a default value.

```java
//build a ResourceModel for key 'greetingMessage'
new ResourceModel("greetingMessage");
```

```java
//build a ResourceModel with a default value
new ResourceModel("notExistingResource", "Resource not found.");
```

--------------------------------

### Use Parameter Placeholders in Mounted Paths

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Defines dynamic segments in mounted paths using placeholders and demonstrates how to provide parameters for these paths.

```java
mountPage("/pageMount/${foo}/otherSegm", MountedPageWithPlaceholder.class);
```

```java
PageParameters pageParameters = new PageParameters();
pageParameters.add("foo", "foo");

setResponsePage(MountedPageWithPlaceholder.class, pageParameters)
```

```text
<Application path>/pageMount/foo/otherSegm
```

```java
mountPage("/pageMount/#{foo}/otherSegm", MountedPageOptionalPlaceholder.class);
```

```java
PageParameters pageParameters = new PageParameters();
setResponsePage(MountedPageWithPlaceholder.class, pageParameters);
```

```text
<Application path>/pageMount/otherSegm
```

--------------------------------

### Creating a Link with Indexed and Named Parameters

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Shows how to configure a Link component to navigate to a page with both indexed and named parameters.

```java
add(new Link<Void>("pageWithNamedIndexParam") {

	@Override
 	public void onClick() {

		PageParameters pageParameters = new PageParameters();
		pageParameters.set(0, "foo");
		pageParameters.set(1, "bar");
		pageParameters.add("baz", "baz");

		setResponsePage(PageWithParameters.class, pageParameters);
	}

});
```

--------------------------------

### Initialize DropDownChoice in Java

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Basic instantiation using a list of strings and a model.

```java
List<String> fruits = Arrays.asList("apple", "strawberry", "watermelon");
form.add(new DropDownChoice<String>("fruits", new Model(), fruits));
```

--------------------------------

### Initialize DropDownChoice with Updating Behavior

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Setup for a DropDownChoice component that updates its model automatically on change events.

```java
Model<Person> listModel = new Model<Person>();
ChoiceRenderer<Person> personRenderer = new ChoiceRenderer<Person>("fullName");
personsList = new DropDownChoice<Person>("persons", listModel, loadPersons(), personRenderer);
personsList.add(new FormComponentUpdatingBehavior());
```

--------------------------------

### Simulate Link Clicks and Assert Label Content

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Shows how to simulate user interaction with links and verify component state using assertLabel.

```java
//...
@Test
void switchLabelTest(){
	//start and render the test page
	tester.startPage(HomePage.class);
	//assert rendered page class
	tester.assertRenderedPage(HomePage.class);
	//assert rendered label
	tester.assertLabel("label", "First label");
	//simulate a click on "reload" button
	tester.clickLink("reload");
	//assert rendered label
	tester.assertLabel("label", "Second label");
}
//...
```

--------------------------------

### Implementing ApplicationContextAware in MyWebApplication

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example implementation of MyWebApplication using ApplicationContextAware to inject the Spring context into the Wicket application.

```java
@Component
public class MyWebApplication extends WebApplication implements ApplicationContextAware {
    @Override
    protected void init() {
        addComponentInstantiationListener(new SpringComponentInjector(this, ctx, true));
    }

    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.ctx = applicationContext;
    }
}
```

--------------------------------

### Generated Wicket AJAX JavaScript Call

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of the final JavaScript function generated by Wicket for an AJAX request.

```javascript
Wicket.Ajax.ajax({"u":"./?0-1.IBehaviorListener.0-clickCounterLabel", "e":"click",
                  "c":"clickCounterLabel1"});
```

--------------------------------

### Configuring WebApplicationPath for Custom Resource Folders

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Shows how to add a WebApplicationPath to the resource finders list to load resources from a specific folder in the webapp root.

```java
@Override
public void init()
{
	getResourceSettings().getResourceFinders().add(
			new WebApplicationPath(getServletContext(), "markupFolder"));
}
```

--------------------------------

### Implementing Data Paging with PagingNavigator

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Configures a DataView with pagination by setting items per page and attaching a PagingNavigator component.

```html
<table>
  <tr>
    <th>ISO 3166-1</th><th>Name</th><th>Long name</th><th>Capital</th><th>Population</th>
  </tr>
  <tr wicket:id="rows">
    <td wicket:id="dataRow"></td>
  </tr>
</table>
```

```java
public HomePage(final PageParameters parameters) {
  super(parameters);
  //method loadCountriesFromCsv is defined elsewhere in the class.
  //It reads countries data from a csv file and returns each row as an array of Strings.
  List<String[]> countries = loadCountriesFromCsv();
  ListDataProvider<String[]> listDataProvider = new ListDataProvider<String[]>(countries);

  DataView<String[]> dataView = new DataView<String[]>("rows", listDataProvider) {
    @Override
    protected void populateItem(Item<String[]> item) {
      String[] countriesArr = item.getModelObject();
      RepeatingView repeatingView = new RepeatingView("dataRow");

      for (int i = 0; i < countriesArr.length; i++){
         repeatingView.add(new Label(repeatingView.newChildId(), countriesArr[i]));
      }
      item.add(repeatingView);
    }
  };

  dataView.setItemsPerPage(15);

  add(dataView);
  add(new PagingNavigator("pagingNavigator", dataView));
}
```

--------------------------------

### Poorly Encapsulated RegistrationForm

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of a Form that exposes internal component structure, making it difficult for users to manage markup.

```java
// Poor component
public class RegistrationForm extends Form<Registration> {
    public RegistrationForm(String id, IModel<Registration> regModel) {
        super(id, new CompoundPropertyModel<Registration>(regModel))
        // Wrong: RegistrationForm provides its own components
        add(new TextField("username"));
        add(new TextField("firstname"));
        add(new TextField("lastname"));
    }
}
```

--------------------------------

### Avoid Conditional Component Construction

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of anti-pattern code that conditionally adds components to the tree, which should be avoided in favor of visibility management.

```java
// typical for struts
if(MySession.get().isNotLoggedIn()) {
    add(new LoginBoxPanel("login"))
}
else {
    add(new EmptyPanel("login"))
}
```

--------------------------------

### Initialize a Label with a String

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Creates a Label component using a constructor that implicitly wraps the provided string in a model.

```java
add(new Label("helloMessage", "Hello WicketWorld!"));
```

--------------------------------

### Implement IRequestListener in a Link component

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of overriding onRequest to invoke a custom onClick handler within a Wicket Link component.

```java
public abstract class Link<T> extends AbstractLink implements IRequestListener ...
{
	/**
	 * Called when a link is clicked.
	 */
	public abstract void onClick();

	/**
	 * THIS METHOD IS NOT PART OF THE WICKET API. DO NOT ATTEMPT TO OVERRIDE OR CALL IT.
	 *
	 * Called when a link is clicked. The implementation of this method is currently to simply call
	 * onClick(), but this may be augmented in the future.
	 */
	@Override
	public void onRequest()
	{
		// Invoke subclass handler
		onClick();
	}
}
```

--------------------------------

### Implement renderHead for Header Contributions

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Use this method to register JavaScript and CSS resources. It includes logic to skip rendering if the component is disabled and handles dynamic script initialization.

```java
@Override
public void renderHead(IHeaderResponse response) {
	super.renderHead(response);

	//if component is disabled we don't have to load the JQueryUI datepicker
	if(!isEnabledInHierarchy())
		return;
	//add bundled JQuery
	JavaScriptLibrarySettings javaScriptSettings =
                      getApplication().getJavaScriptLibrarySettings();
	response.render(JavaScriptHeaderItem.
			forReference(javaScriptSettings.getJQueryReference()));
	//add package resources
	response.render(JavaScriptHeaderItem.
	      forReference(new PackageResourceReference(getClass(), "jquery-ui.min.js")));
	response.render(JavaScriptHeaderItem.
	      forReference(new PackageResourceReference(getClass(), "jquery-ui-i18n.min.js")));
	response.render(CssHeaderItem.
	      forReference(new PackageResourceReference(getClass(), "jquery-ui.css")));
	//add custom file JQDatePicker.js. Reference JQDatePickerRef is a static field
	response.render(JavaScriptHeaderItem.forReference(JQDatePickerRef));

	//add the init script for datepicker
	String jqueryDateFormat = datePattern.replace("yyyy", "yy").toLowerCase();
	String initScript = ";initJQDatepicker('" + getMarkupId() + "', '" + countryIsoCode +
                            "', '" + jqueryDateFormat + "', " + "'" + urlForIcon +"');";
	response.render(OnLoadHeaderItem.forScript(initScript));
}
```

--------------------------------

### SignInPage Implementation

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Handles user credentials via a StatelessForm and redirects to the original destination upon successful authentication.

```java
public class SignInPage extends WebPage {
   private String username;
   private String password;

   @Override
   protected void onInitialize() {
      super.onInitialize();

      StatelessForm<Void> form = new StatelessForm<Void>("form") {
         @Override
         protected void onSubmit() {
            if(Strings.isEmpty(username))
               return;

            boolean authResult = AuthenticatedWebSession.get().signIn(username, password);
            //if authentication succeeds redirect user to the requested page
            if(authResult)
               continueToOriginalDestination();
         }
      };

      form.setModel(new CompoundPropertyModel(this));

      form.add(new TextField("username"));
      form.add(new PasswordTextField("password"));

      add(form);
   }
}
```

--------------------------------

### Apply HTTPS via Inheritance or Marker Interfaces

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Demonstrates securing multiple pages by annotating a base class or a marker interface.

```java
// Marker interface:
@RequireHttps
public interface IMarker {
}

// Base class:
@RequireHttps
public class BaseClass extends WebPage {
//Page code...
}

// Secure page inheriting from BaseClass:
public class HttpsPage extends BaseClass {
//Page code...
}

// Secure page implementing IMarker:
public class HttpsPage extends WebPage implements IMarker {
//Page code...
}
```

--------------------------------

### Set and Get Session Style

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Use these methods on the Session object to define or retrieve the style parameter for resource bundle lookup.

```java
Session.get().setStyle("myStyle");
Session.get().getStyle();
```

--------------------------------

### Add CSS resource to component header

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of a custom component loading a CSS file as a package resource and adding it to the page header.

```java
public class MyComponent extends Component{

  @Override
  public void renderHead(IHeaderResponse response) {
      PackageResourceReference cssFile =
                            new PackageResourceReference(this.getClass(), "style.css");
    CssHeaderItem cssItem = CssHeaderItem.forReference(cssFile);

    response.render(cssItem);
  }
}
```

--------------------------------

### Implement a StatelessLink

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Demonstrates a StatelessLink component within a stateless WebPage. Note that onClick() logic cannot rely on instance variables as a new page instance is created for each request.

```java
public class StatelessPage extends WebPage {
	private int index = 0;

	public StatelessPage(PageParameters parameters) {
		super(parameters);
	}

	@Override
	protected void onInitialize() {
		super.onInitialize();
		setStatelessHint(true);

		add(new StatelessLink("statelessLink") {

			@Override
			public void onClick() {
				//It will always print zero
				System.out.println(index++);
			}

		});
	}
}
```

--------------------------------

### Bundle Naming Convention Patterns

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

These patterns illustrate how style and variation parameters are incorporated into the resource bundle file naming structure.

```text
<base name>[_style][_<language code>[_<COUNTRY_CODE>[_<variant code>]]]
```

```text
<base name>[_variation][_style][_<language code>[_<COUNTRY_CODE>[_<variant code>]]]
```

--------------------------------

### Main template page with wicket:child

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

A layout example replacing a standard div with the wicket:child tag for dynamic content injection.

```html
<html>
<head>
	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<div id="header" wicket:id="headerPanel">header</div>
<div id="body">
	<div id="menu" wicket:id="menuPanel">menu</div>
	<wicket:child/>
</div>
<div id="footer" wicket:id="footerPanel">footer</div>
</body>
</html>
```

--------------------------------

### Configure Wicket deployment mode as context parameter

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Define the configuration parameter as a context-param in the deployment descriptor.

```xml
<context-param>
    <param-name>configuration</param-name>
    <param-value>deployment</param-value>
</context-param>
```

--------------------------------

### Implementing a Stateful HomePage

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Example of a stateful page that modifies its component hierarchy within a Link's onClick method to trigger a new page version.

```java
public class HomePage extends WebPage
{
	private static final long serialVersionUID = 1L;
	private Label firstLabel;
	private Label secondLabel;

	public HomePage(){
		firstLabel = new Label("label", "First label");
		secondLabel = new Label("label", "Second label");

		add(firstLabel);

		add(new Link<Void>("reload"){
			@Override
			public void onClick() {
				if(getPage().contains(firstLabel, true))
					getPage().replace(secondLabel);
				else
					getPage().replace(firstLabel);
			}
		});

	}
}
```

--------------------------------

### Using ContextImage for pictures

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Creating a component for image tags using a context path.

```java
//build the component specifying its id and picture's context path
ContextImage image = new ContextImage("myPicture", "/misc/imgs/mypic.png");
```

--------------------------------

### Implement ModalDialog in Java

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Initializes a ModalDialog, sets its content, and triggers it via an AjaxLink.

```java
public HomePage(final PageParameters parameters) {
   	super(parameters);
    	final ModalDialog modal = new ModalDialog("modal");
    	modal.add(new DefaultTheme());
    	modal.closeOnClick();
    	Label label = new Label(ModalDialog.CONTENT_ID, "I'm a modal dialog!");

    	modal.setContent(label);

    	add(modal);
    	add(new AjaxLink<Void>("open") {
		@Override
		public void onClick(AjaxRequestTarget target) {
			modal.open(target);
		}
	});
}
```

--------------------------------

### Implement a JPA-based LoadableDetachableModel

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

A custom model implementation that uses JPA to load and detach entities. Note that this example lacks production-ready features like transaction management.

```java
public class JpaLoadableModel<T> extends LoadableDetachableModel<T> {

    private EntityManagerFactory entityManagerFactory;
    private Class<T> entityClass;
    private Serializable identifier;
    private List<Object> constructorParams;

    public JpaLoadableModel(EntityManagerFactory entityManagerFactory, T entity) {

        super();

        PersistenceUnitUtil util = entityManagerFactory.getPersistenceUnitUtil();

        this.entityManagerFactory = entityManagerFactory;
        this.entityClass = (Class<T>) entity.getClass();
        this.identifier = (Serializable) util.getIdentifier(entity);

        setObject(entity);
    }

    @Override
    protected T load() {
        T entity = null;

        if(identifier != null) {
            EntityManager entityManager = entityManagerFactory.createEntityManager();
            entity = entityManager.find(entityClass, identifier);
        }
        return entity;
    }

    @Override
    protected void onDetach() {
        super.onDetach();

        T entity = getObject();
        PersistenceUnitUtil persistenceUtil = entityManagerFactory.getPersistenceUnitUtil();

        if(entity == null) return;

        identifier = (Serializable) persistenceUtil.getIdentifier(entity);
    }
}
```

--------------------------------

### Implement Jetty9PushBuilder

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Create a server-specific implementation of the PushBuilder interface for Jetty.

```java
public class Jetty9PushBuilder implements PushBuilder
{
	@Override
	public void push(HttpServletRequest httpServletRequest, String... paths)
	{
		Request request = RequestCycle.get().getRequest();
		HttpServletRequest httpRequest = (HttpServletRequest) request.getContainerRequest();
		org.eclipse.jetty.server.PushBuilder pushBuilder =
		      org.eclipse.jetty.server.Request.getBaseRequest(httpRequest).getPushBuilder();
		for (String path : paths)
		{
			pushBuilder.path(path);
		}
		pushBuilder.push();
	}
}
```

--------------------------------

### Configure GraphiteReporter in Application init

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Initialize the GraphiteReporter within the Wicket Application's init method to start collecting metrics. Stop the reporter in the onDestroy method to ensure clean shutdown.

```java
	private GraphiteReporter reporter;

	@Override
	protected void init()
	{
		MetricRegistry metricRegistry = WicketMetrics.getMetricRegistry();
		final Graphite graphite = new Graphite(new InetSocketAddress("127.0.0.1", 2003));
		reporter = GraphiteReporter.forRegistry(metricRegistry).prefixedWith("WebApplications")
			.convertRatesTo(TimeUnit.SECONDS).convertDurationsTo(TimeUnit.MILLISECONDS)
			.filter(MetricFilter.ALL).build(graphite);

		// Collects data every 5 seconds
		reporter.start(5, TimeUnit.SECONDS);
	}

	@Override
	protected void onDestroy()
	{
		super.onDestroy();
		reporter.stop();
	}
```

--------------------------------

### Configure Responsive Image Component

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Uses the Image component with multiple ResourceReferences and size attributes to enable browser-side image selection.

```HTML
...
	Package resource image: <img wicket:id="packageResPicture"/>
...
```

```Java
...
		Image image = new Image("packageResPicture",
			new PackageResourceReference(getClass(),"small.jpg"),
			new PackageResourceReference(getClass(), "large.jpg"),
			new PackageResourceReference(getClass(), "medium.jpg"),
			new PackageResourceReference(getClass(), "small.jpg"));
		image.setXValues("1024w", "640w", "320w");
		image.setSizes("(min-width: 36em) 33.3vw", "100vw");

		this.add(image);
...
```

--------------------------------

### Implement PersonListDetails Page

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Full implementation of a WebPage using a CompoundPropertyModel chained to a DropDownChoice model.

```java
public class PersonListDetails extends WebPage {
  private Form<Void> form;
  private DropDownChoice<Person> personsList;

  public PersonListDetails(){
    Model<Person> listModel = new Model<Person>();
    ChoiceRenderer<Person> personRender = new ChoiceRenderer<Person>("fullName");

    personsList = new DropDownChoice<Person>("persons", listModel, loadPersons(), personRender);
    personsList.add(new FormComponentUpdatingBehavior());

    add(personsList);

    form = new Form<>("form", new CompoundPropertyModel<Person>(listModel));
    form.add(new TextField("name"));
    form.add(new TextField("surname"));
    form.add(new TextField("address"));
    form.add(new TextField("email"));

    add(form);
  }

   //loadPersons()
   //...
```

--------------------------------

### Redirect to Another Page by Instance

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Uses setResponsePage with a specific page instance to navigate.

```java
@Override
public void onClick() {
	//we redirect browser to another page.
	AnotherPage anotherPage = new AnotherPage();
	setResponsePage(anotherPage);
}
```

--------------------------------

### Implement Picture Component with Sources

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Uses the Picture component to manage multiple Source components and a fallback Image for granular control over media presentation.

```HTML
...
	<picture wicket:id="picture">
  		<source wicket:id="big" />
  		<source wicket:id="small" />
  		<img wicket:id="fallback" />
	</picture>
...
```

```Java
...
		Picture picture = new Picture("picture");

		Source big = new Source("big", new PackageResourceReference(getClass(), "big.jpg"), new PackageResourceReference(getClass(), "big-hd.jpg"));
		big.setXValues("1x","2x");
		big.setMedia("(min-width: 40em)");
		picture.add(big);

		Source small = new Source("small", new PackageResourceReference(getClass(), "small.jpg"), new PackageResourceReference(getClass(), "small-hd.jpg"));
		small.setXValues("1x","2x");
		picture.add(small);

		Image image = new Image("fallback", new PackageResourceReference(getClass(), "fallback.jpg"));
		picture.add(image);

		this.add(picture);
...
```

--------------------------------

### Implement a basic LoginForm

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

A standard form implementation using TextField, PasswordTextField, and Label components with explicit models.

```java
public class LoginForm extends Form {

	private TextField usernameField;
	private PasswordTextField passwordField;
	private Label loginStatus;

	public LoginForm(String id) {
		super(id);

		usernameField = new TextField("username", Model.of(""));
		passwordField = new PasswordTextField("password", Model.of(""));
		loginStatus = new Label("loginStatus", Model.of(""));

		add(usernameField);
		add(passwordField);
		add(loginStatus);
	}

	public final void onSubmit() {
		String username = (String)usernameField.getDefaultModelObject();
		String password = (String)passwordField.getDefaultModelObject();

		if(username.equals("test") && password.equals("test"))
			loginStatus.setDefaultModelObject("Congratulations!");
		else
			loginStatus.setDefaultModelObject("Wrong username or password!");
	}
}
```

--------------------------------

### Configure Media Tags with Range Support

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Uses the Video component with readBuffered(false) to stream media directly without loading the entire resource into memory.

```HTML
...
     <video wicket:id="video" />
...
```

```Java
...
    Video video = new Video("video", new PackageResourceReference(getClass(),"video.mp4").readBuffered(false));
...
```

--------------------------------

### Define and set metadata in a Wicket Application

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Demonstrates defining a static MetaDataKey and setting a value within the init method of a WebApplication.

```java
public class MetaDataApp extends WebApplication{
	//Do some stuff...
	/**
	* Metadata key definition
	*/
	public static MetaDataKey<Connection> connectionKey = new MetaDataKey<> (){};

	/**
	 * Application's initialization
	 */
	@Override
	public void init(){

		super.init();
		Connection connection;
		//connection initialization...
		setMetaData(connectionKey, connection);
		//Do some other stuff..

	}
}
```

--------------------------------

### Use wicket:link for Package Resources

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Automatically resolves URLs for package resources like images, CSS, or scripts directly within the markup.

```HTML
<wicket:link>
   <img src="icon.png"/>
</wicket:link>
```

--------------------------------

### Configure Wicket with Spring Integration

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Deployment descriptor configuration using SpringWebApplicationFactory and ContextLoaderListener.

```xml
<web-app>
    <filter>
        <filter-name>wicketfilter</filter-name>
        <filter-class>org.apache.wicket.protocol.http.WicketFilter</filter-class>
        <init-param>
            <param-name>applicationFactoryClassName</param-name>
            <param-value>org.apache.wicket.spring.SpringWebApplicationFactory</param-value>
        </init-param>
    </filter>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml</param-value>
    </context-param>
</web-app>
```

--------------------------------

### Initialize form components with models

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Snippet showing the assignment of empty string models to form components.

```java
usernameField = new TextField("username", Model.of(""));
passwordField = new PasswordTextField("password", Model.of(""));
loginStatus = new Label("loginStatus", Model.of(""));
```

--------------------------------

### Implement IMarkupResourceStreamProvider for Dynamic Markup

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Create a custom panel that generates its own HTML markup by implementing the IMarkupResourceStreamProvider interface.

```java
public class AutoMarkupGenPanel extends Panel implements IMarkupResourceStreamProvider {
	public AutoMarkupGenPanel(String id, IModel<?> model) {
		super(id, model);
	}

	@Override
	public IResourceStream getMarkupResourceStream(MarkupContainer container,
			Class<?> containerClass) {
		String markup = "<wicket:panel><div>Panel markup</div></wicket:panel>";
		StringResourceStream resourceStream = new StringResourceStream(markup);

		return resourceStream;
	}
}
```

--------------------------------

### Create AJAX Components with Lambdas

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Use ComponentFactory to build AJAX links and submit links with lambda expressions.

```java
//create an AJAX link component
add(ComponentFactory.ajaxLink("id", (ajaxLink, ajaxTarget) -> {/*do stuff*/});

//create a submit link with error handler
add(ComponentFactory.ajaxSubmitLink("id", (ajaxLink, ajaxTarget) -> {/*do submit stuff*/},
                                   (ajaxLink, ajaxTarget) -> {/*do error stuff*/});
```

--------------------------------

### Mount a Page to a Path

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Configures page mounting within the application's init method and retrieves the generated URL for a mounted page class.

```java
@Override
public void init()
{
	super.init();
	mountPage("/pageMount", MountedPage.class);
	//Other initialization code...
}
```

```java
//it will return "/pageMount"
RequestCycle.get().urlFor(MountedPage.class);
```

```java
public final <T extends Page> void mountPage(final String path,final Class<T> pageClass) {
	mount(new MountedMapper(path, pageClass));
}
```

--------------------------------

### Usage of Well Encapsulated RegistrationInputPanel

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Demonstrates the clean usage of the encapsulated panel within a page.

```java
public class RegistrationPage extends Page {
    public RegistrationPage(IModel<Registration> regModel) {
        Form<?> form = new Form("form");
        form.add(new RegistrationInputPanel("registration", regModel));
        form.add(new SubmitButton("register") {
            public void onSubmit() {
              // do something
            }
        });
        add(form);
    }
}
```

```html
<html>
<body>
    <form wicket:id="form">
        <div wicket:id="registration">
           Display the RegistrationInputPanel
        </div>
        <input type="submit" wicket:id="register" value="Register"/>
    </form>
</body>
</html>
```

--------------------------------

### Adding a Panel to a Container

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Instantiate a custom panel and add it to the current container.

```java
MyPanel myPanel = new MyPanel ("innerContainer");
add(myPanel);
```

--------------------------------

### Register and Use WebSocketResource

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Register a WebSocketResource in the application init method and connect it to a page using BaseWebSocketBehavior.

```java
getSharedResources().add("someName", new MyWebSocketResource());
```

```java
page.add(new BaseWebSocketBehavior("someName"));
```

--------------------------------

### Mount a Resource using a Lambda Supplier

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Mount a resource by providing a supplier to the ResourceReference.of factory method.

```java
@Override
public void init() {
  super.init();

  IResource helloWorldRes = (attributes) ->
     attributes.getResponse().write("Hello world!");

  ResourceReference resRef = ResourceReference.of("helloworld", () -> helloWorldRes);

  mountResource("/helloworld", resRef);
}
```

--------------------------------

### Implement IInitializer

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Create a class implementing IInitializer to define custom logic during application bootstrap and termination.

```java
public class MyInitializer implements IInitializer{

	public void init(Application application) {
		//initialization code
	}

	public void destroy(Application application) {
		//code to execute when application is terminated
	}
}
```

--------------------------------

### Form with Button components

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Demonstrates a Wicket form using Button components with string models for labels and a default button configuration.

```html
<body>
	<form wicket:id="form">
		Username: <input type="text" wicket:id="username"/>
		<br/>
		<input type="submit" wicket:id="submit1"/>
		<input type="submit" wicket:id="submit2"/>
	</form>
</body>
```

```java
public class HomePage extends WebPage {

	public HomePage(final PageParameters parameters) {
		Form<Void> form = new Form<>("form");

	    form.add(new TextField("username", Model.of("")));
	    form.add(new Button("submit1", Model.of("First submitter")));
		Button secondSubmitter;
		form.add(secondSubmitter = new Button("submit2", Model.of("Second submitter")));

	    form.setDefaultButton(secondSubmitter);
		add(form);
	}
}
```

```html
<form wicket:id="form" id="form1" method="post" action="?0-1.IFormSubmitListener-form">
   <div>
      ...
      <!-- Code generated by Wicket to handle the default button -->
      ...
   </div>
   Username: <input type="text" wicket:id="username" value="" name="username"/>
   <br/>
   <input type="submit" wicket:id="submit1" name="submit1" id="submit13" value="First submitter"/>
   <input type="submit" wicket:id="submit2" name="submit2" id="submit22" value="Second submitter"/>
</form>
```

--------------------------------

### Accessing and Setting the Resource Locator

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Demonstrates how to retrieve or replace the default IResourceStreamLocator within the application's init method.

```java
  //init application's method
  @Override
  public void init(){
    //get the resource locator
    getResourceSettings().getResourceStreamLocator();
    //set the resource locator
    getResourceSettings().setResourceStreamLocator(myLocator);
  }
```

--------------------------------

### Clone the Apache Wicket repository

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Use this command to clone your forked Apache Wicket repository to your local machine.

```bash
git clone https://github.com/<<your github username>>/wicket.git
```

--------------------------------

### Aggregate resources into bundles

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Use getResourceBundles() during application initialization to merge multiple JavaScript or CSS files into a single request.

```java
@Override
public void init() {
  super.init();

  getResourceBundles().addJavaScriptBundle(WicketApplication.class,
                "jqueryUiJs",
                jqueryJsReference,
                jqueryUiJsReference);

  getResourceBundles().addCssBundle(WicketApplication.class,
                 "jqueryUiCss",
                jqueryCssReference,
                jqueryUiCssReference);

}
```

--------------------------------

### Test Components in Isolation

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Uses startComponentInPage to render a component independently for unit testing.

```java
//...
@Test
void testCustomPanelContainsLabel(){
	TemperatureDegreeField field = new TemperatureDegreeField("field", Model.of(0.00));
	//Use standard JUnit class Assertions
	Assertions.assertNull(field.get("measurementUnit"));
	tester.startComponentInPage(field);
	Assertions.assertNotNull(field.get("measurementUnit"));
}
//...
```

--------------------------------

### Using wicket:link for Bookmarkable Pages

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Wraps anchors in a wicket:link tag to automatically resolve bookmarkable links based on package-relative paths.

```html
<!DOCTYPE html>
<html xmlns:wicket="http://wicket.apache.org">
	<head>
		<meta charset="utf-8" />
		<title>Apache Wicket Quickstart</title>
	</head>
	<body>
	   <div id="bd">
	      <wicket:link>
			<a href="HomePage.html">HomePage</a><br/>
			<a href="anotherPackage/SubPackagePage.html">SubPackagePage</a>
	      </wicket:link>
	   </div>
	</body>
</html>
```

```html
<a href="/org/wicketTutorial/anotherPackage/SubPackagePage.html"> SubPackagePage</a>
```

```html
<!DOCTYPE html>
<html xmlns:wicket="http://wicket.apache.org">
	<head>
		<meta charset="utf-8" />
		<title>Apache Wicket Quickstart</title>
	</head>
	<body>
		<div id="bd">
			<wicket:link>
				<a href="../HomePage.html">HomePage</a><br/>
				<a href="SubPackagePage.html">SubPackagePage</a>
			</wicket:link>
		</div>
	</body>
</html>
```

```html
<a disabled="disabled">HomePage</a>
```

--------------------------------

### Implement Component Visibility via onConfigure

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Use the Hollywood principle by overriding onConfigure() to allow components to manage their own visibility state autonomously.

```java
// Poor implementation
LoginBoxPanel loginBox = new LoginBoxPanel("login");
loginBox.setVisible(MySession.get().isNotLoggedIn());
add(loginBox);
```

```java
public class LoginBoxPanel {
    // constructor etc.
    @Override
    public void onConfigure() {
        setVisible(MySession.get().isNotLoggedIn());
    }
}
```

--------------------------------

### Chain Multiple Initializers

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Use a main initializer to execute multiple initialization tasks when only one initializer is allowed per properties file.

```java
public class MainInitializer implements IInitializer{

	public void init(Application application) {
		new AnotherInitializer().init(application);
		new YetAnotherInitializer().init(application);
		//...
	}
	//destroy...
}
```

--------------------------------

### Mounting resources to URL paths

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Register resources at the application level using mountResource, supporting both static paths and path parameters.

```java
@Override
public void init() {
  super.init();
  //resource mounted to path /foo/bar
  ResourceReference resourceReference = new ResourceReference("rssProducer"){
     RSSReaderResource rssResource = new RSSReaderResource();
     @Override
     public IResource getResource() {
	return rssResource;
  }};
  mountResource("/foo/bar", resourceReference);
}
```

```java
@Override
public void init() {
  super.init();
  //resource mounted to path /foo with a required indexed parameter
  ResourceReference resourceReference = new ResourceReference("rssProducer"){
     RSSReaderResource rssResource = new RSSReaderResource();
     @Override
     public IResource getResource() {
	return rssResource;
  }};
  mountResource("/bar/${baz}", resourceReference);
}
```

--------------------------------

### Implement Model-Bound Visibility

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Configure component visibility dynamically based on the current model object state within onConfigure().

```java
new Label("headline", headlineModel) {
    @Override
    public void onConfigure() {
        // Headline visible only if text starts with "Berlusconi"
        String headline = getModelObject();
        setVisible(headline.startsWith("Berlusconi"));
    }
}
```

--------------------------------

### Managing Indexed Parameters with PageParameters

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Demonstrates adding and retrieving indexed parameters using the PageParameters class.

```java
PageParameters pageParameters = new PageParameters();
//add a couple of parameters
pageParameters.set(0, "foo");
pageParameters.set(1, "bar");
//retrieve the value of the second parameter ("bar")
pageParameters.get(1);
```

--------------------------------

### Configure CSS Compressor in WebApplication

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Register a CSS compressor or URL replacer within the init method of your WebApplication class.

```java
...
    public class WicketApplication extends WebApplication
    {
        @Override
        public Class<? extends WebPage> getHomePage()
        {
            return HomePage.class;
        }

        @Override
        public void init()
        {
           super.init();
            getResourceSettings().setCssCompressor(new CssUrlReplacer());
        }
    }
...
```

--------------------------------

### Initialize Border and Add Children

Source: https://nightlies.apache.org/wicket/guide/10.x/single.html

Use addToBorder for components inside the border markup and add for components inside the tag body.

```java
MyBorder myBorder = new MyBorder("myBorder");

myBorder.addToBorder(new Label("childMarkup", "Child inside markup."));
myBorder.add(new Label("childTag", "Child inside tag."));

add(myBorder);
```
Tokens:
Raw