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. The namespace is different per Wicket version:
Wicket 1.4: http://wicket.apache.org/dtds.data/wicket-xhtml1.4-strict.dtd Wicket 1.3: http://wicket.apache.org/dtds.data/wicket-xhtml1.3-strict.dtd Wicket 1.2 and earlier: http://wicket.sourceforge.net/
For example the first lines of a markup file could be:
<?xml version="1.0" encoding="UTF-8"?> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:wicket="http://wicket.apache.org/dtds.data/wicket-xhtml1.4-strict.dtd" xml:lang="da" lang="da">
or
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:wicket="http://wicket.apache.org/dtds.data/wicket-xhtml1.3-strict.dtd"
xml:lang="en"
lang="en">
This will setup the "wicket" namespace for Wicket tags. You can change the namespace used, for example xmlns:wcn="DTD here" will change it to "wcn" for this markup file only. Without any xmlns declaration the default is "wicket". Just using xmlns:wicket and xmlns:wcn on their own 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) is change the namespace within the very same markup file per tag. Wicket does allow it only with the html tag.
If your IDE needs a DTD, for Wicket 1.3 and later the namespace is also the URL where the DTD can be retrieved.
Wicket Attributes
Attribute wicket:id
wicket:id="ID_HERE" - Used on any element to which you want to add a component.
<span wicket:id="hellotext">Hello</span>
The value of the attribute is duplicated in the java code:
add(new Label("hellotext", "Hello World"));
Attribute wicket:message
wicket:message="attribute:resource_identifier" - Used on any tag that we want Wicket to provide an attribute with a value that's the result of a resource lookup.
e.g. <input type="submit" wicket:message="value:page.search"/> => <input type="submit" value="Search Page""/>
Use comma separator if you have more than one attribute for internationalization:
e.g. <img src="some.gif" wicket:message="alt:page.image.alt,title:page.image.title"/> => <img src="some.gif" alt="The Alt" title="The title"/>
Wicket Tags
Element wicket:link
<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>
Now if you request Index.html it gets transformed to:
<span><em>Link to wicket document Index.html</em></span>
If you want to change the markup to something else you can configure your wicket webapp in the init() method like
getMarkupSettings().setDefaultBeforeDisabledLink("<bold>");
getMarkupSettings().setDefaultAfterDisabledLink("</bold>");
Which will result into to following:
<span><bold>Link to wicket document Index.html</bold></span>
Element wicket:panel
<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>
Elements wicket:border and wicket:body
<wicket:border> and <wicket:body> - (I think this is the same as wicket:panel, except a border is drawn by default; verify).
Element wicket:extend
<wicket:extend> - Extend the markup of the superclass with this content.
Element wicket:child
<wicket:child> - Wicket will remove this content with the markup of the derived component (see <wicket:extend>)
Element wicket:message
<wicket:message> - Wicket will replace this with a string that is retrieved from a resource bundle. e.g.
<wicket:message key="page.label">Default label</wicket:message>
Starting from Wicket 1.4 you can nest components within a wicket:message element. For example:
<wicket:message key="myKey">
This text will be replaced with text from the properties file.
<span wicket:id="amount">[amount]</span>.
<a wicket:id="link">
<wicket:message key="linkText"/>
</a>
</wicket:message>
myKey=Your balance is ${amount}. Click ${link} to view the details.
linkText=here
and
add(new Label("amount",new Model("$5.00")));
add(new BookmarkablePageLink("link",DetailsPage.class));
Results in:
Your balance is $5.00. Click <a href="...">here</a> to view the details.
Element wicket:remove
<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 that content using a ListView (or other loop).
Element wicket:head
<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>
Element wicket:component
<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. (THIS TAG IS NOT SUPPORTED BY THE CORE TEAM)
Element wicket:enclosure
<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>
add(new Label("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 in the enclosure's child attribute:
<wicket:enclosure child="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>
For nested children, specify the full path, separating them with ":", i.e.
<wicket:enclosure child="users:fax"> <table wicket:id="users"> <tr><td class="label">Fax:</td><td><span wicket:id="fax">fax number</span></td></tr> </table> </wicket:enclosure>
Note: Changing the visibility of a child component in Ajax callback method will not affect the entire enclosure but just the child component itself. This is because only the child component is added
to the AjaxRequestTarget.
Element wicket:container
<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.
Note that you cannot use HTML markup IDs on <wicket:container> elements. E. g. you cannot replace such an element via AJAX.