Question

I am trying to extend tree component in Vaadin. So I created client side class as:

import com.vaadin.terminal.gwt.client.ui.VTree;
public class CustomVtree extends VTree {
}

Server side class :

import com.vaadin.ui.ClientWidget;
import com.vaadin.ui.Tree;
@ClientWidget(CustomVtree.class)
public class MyTree extends Tree {
    public MyTree() {
        super();
    }
}

And I got
[WARN] Widget class com.vaadin.sample.gwt.client.ui.CustomVtree was not found. The component com.vaadin.sample.gwt.client.ui.MyTree will not be included in the widgetset.
What did I forget to do or what I am doing wrong? Will be glad for any help. Thanks

Answer 1

Your classes look correct but one thing is missing: a GWT module descriptor file. Add that file to the com.vaadin.sample.gwt package and here I call it MyWidgetset.gwt.xml. The content of the file should look like the following if you don’t have any add-ons in your project:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC "-//Google Inc.//DTD Google Web Toolkit 1.7.0//EN" "http://google-web-toolkit.googlecode.com/svn/tags/1.7.0/distro-source/core/src/gwt-module.dtd">
<module>
    <inherits name="com.vaadin.terminal.gwt.DefaultWidgetSet" />
</module>

And then you have to define in web.xml that you want to use this widgetset:

<init-param>
    <description>Application widgetset</description>
    <param-name>widgetset</param-name>
    <param-value>com.vaadin.sample.gwt.MyWidgetset</param-value>
</init-param>

After these steps the GWT compilation should work.