Syntax:

`   `a_class `   `a_version `   `a_version

[Optional]

It specifies the version of this configuration. It also controls whether to ignore this configuration.

First, ZK checks if the specified class (<version-calss>) matches the version (<version-uuid>). Second, it checks if ZK’s version is the same or larger than the version specified in <zk-version>.

The specified class, if any, must have a static field called UID. ZK will compare its value with the version specified in <version-uuid>. For example,

package foo;
public class MyAddon {
    public static public static final String UID = "1.0.3";
}

Then, you could specify it as follows.

<version>
    <version-class>foo.MyAddon</version-class>
    <version-uid>1.0.3</version-uid>
    <zk-version>5.0.0</zk-version>
</version>

which means foo.MyAddon.UID must be 1.0.3, and

org.zkoss.zk.ui.WebApp

must be 5.0.0 or later.