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The HTML documents that Wicket uses as templates can contain several special attributes and tags

Using Wicket Tags

To make most HTML editors not complain about using wicket tags and attributes, you need to declare the namespace:

    <html xmlns:wicket="http://wicket.sourceforge.net/">

By the way. This is as well how you may change the namespace Wicket will apply for this file. E.g. xmlns:wcn="http://wicket.sourceforge.net" will change it to "wcn" for this markup file only. Without any xmlns declaration the default is "wicket". xmlns:wicket and xmlns:wcn will work as well, as long as you don't have any additional namespace declarations.
What you can not do (but is possible with XHTML) that you change the namespace within the very same markup file per tag. Wicket does allow it only with the html tag.

Wicket Attributes

  • wicket:id="ID_HERE" - Used on any tag that we want Wicket to replace.

    Example:
    <span wicket:id="hellotext">Hello World</span>

Wicket Tags

  • <wicket:link> - Support for wicket autolink functionality. Normally, you need to add a model (for example, a BookmarkablePageLink) for each link that Wicket manages. Using the wicket:link tag will automatically do this in the background for you.

Example:
<wicket:link><a href="Index.html">Link to wicket document Index.html</a></wicket:link>

  • <wicket:panel> - The wicket:panel tag surrounds a component. This lets you wrap the component with HTML and BODY tags (so it can be displyed in a browser) but, when you include it, only the content inside the wicket:panel tag is actually included.
    Example:
    <html xmlns:wicket="http://wicket.sourceforge.net/">
      <body>
        <wicket:panel>
          PANEL CONTENT HERE
        </wicket:panel>
      </body>
    </html>
  • <wicket:border> and <wicket:body> - (I think this is the same as wicket:panel, except a border is drawn by default; verify).
  • <wicket:extend> - Extend the markup of the superclass with this content.
  • <wicket:child> - Wicket will remove this content with the markup of the derived component (see <wicket:extend>)
  • <wicket:remove> - Wicket will remove this content in the final markup. This is useful for when you want your web designer to be able to show repeated content when they're working on it, but you want to generate at content using a ListView (or other loop).
  • <wicket:head> - Used for header contributions. Using this, panels can add header sections to the pages they are place on. For instance:
    <wicket:head>
      <script type="text/javascript">
      function foo() {
         alert("Hello, World!");
      }
    </script>
    </wicket:head>
    <wicket:panel>
      <a href="#" onclick="foo();">Click me!</a>
    </wicket:panel>
  • <wicket:component> - Creates a Wicket component on the fly. Needs a class attribute. Though this has been in wicket for a long time, it is still kind of an unsupported feature, as most of the core developers believe that this may lead to misuse of the framework. Before heavily relying on this feature, you might want to contact the user list to discuss alternative strategies.
  • <wicket:message> - Wicket will replace this with a string that is retrieved from a resource bundle. TODO: more information please...
  • <wicket:enclosure> - (since 1.3) This tag is useful for filtering markup that surrounds a component but has its visibility dependent on the visibility of that component. Lets take a simple example of where you want to show a table row, but only if a Label is visible. 
    <tr><td class="label">Phone:</td><td><span wicket:id="phone">phone number</span></td></tr>
<wicket:enclosure>
<tr><td class="label">Fax:</td><td><span wicket:id="fax">fax number</span></td></tr>
</wicket:enclosure>

new Label(this, "fax") { public boolean isVisible() { return getModelObjectAsString()!=null; }}

If the label is not visible then neither is the contents of the enclosure. Without the enclosure you would have to add an extra WebMarkupContainer to your code and attach it to the tr tag then link its visibility to that of the label, with wicket:enclosure it is much simpler.

If there are more then one wicket components directly underneath the enclosure you have to specify which one controls the visibility by providing its id to the enclosure tag:

<wicket:enclosure id="address.street">
<tr>
  <td class="label">Address:</td>
  <td><span wicket:id="address.street"></span><span wicket:id="address.city"></span></td>
</tr>
</wicket:enclosure>

To use this feature you need to register EnclosureResolver and EnclosureHandler. To do this, add
the following lines to you Application class init method:

		getPageSettings().addComponentResolver(new EnclosureResolver());
		getMarkupSettings().setMarkupParserFactory(new MarkupParserFactory() {
			@Override
			public MarkupParser newMarkupParser(MarkupResourceStream resource) {
				MarkupParser parser = super.newMarkupParser(resource);
				parser.registerMarkupFilter(new EnclosureHandler());
				return parser;
			}
		});
  • <wicket:container> - Sometimes adding components in certain ways may lead to output of invalid markup. For example, lets pretend we output table rows two at a time using a repeater. The markup would look something like this: 
    
 	<table>
 		<span wicket:id="repeater">
 			<tr><td>...</td></tr>
 			<tr><td>...</td></tr>
 		</span>
 	</table>

Notice that we had to attach the repeater to a component tag - in this case a span, but a span is not a legal tag to nest under table. So we can rewrite the example as following:

 	<table>
 		<wicket:container wicket:id="repeater">
			<tr><td>...</td></tr>
 			<tr><td>...</td></tr>
 		</wicket:container>
 	</table>

The above is valid markup because wicket namespaced tags are allowed anywhere.

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