From Documentation
You have two ways to import java methods to EL. Through xel-method, or taglib.
Through xel-method
you can use a processing instruction called the xel-method as follows.
<?xel-method prefix="c" name="forName"
class="java.lang.Class"
signature="java.lang.Class forName(java.lang.String)"?>
<textbox value="${c:forName('java.util.List')}"/>
In example above, Class.forName("java.util.List") is called.
Through taglib
To import EL functions from TLD(TagLib Definition)[1] files, you could use a processing instruction called taglib as follows.[2]
<?taglib uri="http://www.zkoss.org/dsp/web/core" prefix="c" ?>
In the following example, we use function l to get the property app.title defined in resource file.[3]
<window title="${c:l('app.title')}">
Inside core.dsp.tld, you can find the definition of function l.
<function> <name>l</name> <function-class>org.zkoss.xel.fn.CommonFns</function-class> <function-signature>java.lang.String getLabel(java.lang.String)</function-signature> <description> Returns the label of the specified key. </description> </function>
Notes
- The Developer's Reference provides more details on EL expressions. Or, you might refer to JSP 2.0 tutorials or guides for more information about EL expressions.
- ↑ http://java.sun.com/products/jsp/tutorial/TagLibraries17.html
- ↑ http://www.zkoss.org/dsp/web/core is not really an URL. It's a key to tell ZK loader to find the tld file inside ZK jar files.
- ↑ It's a way to retrieve resources for different locale. Please refer to Chapter. Internationalization