Vaadin 7 Refresher插件不起作用

Question

I'm migrating from Vaadin 6 to Vaadin 7.
After changing Refresher for Vaadin 6 to Refresher for Vaadin 7, It seems that I should just change addComponent(refresher) to addExtension(refresher). But unfortunatelly when I did it I recieved an empty page instead of my component. Can anybody help? I don't fully understand what I should do..

Answer 1

Here's an example code of I used:

public class RefresherDemo extends UI  {
    Refresher refresher;
    Label timeLabel;    

    protected void init(VaadinRequest request) {
        final VerticalLayout layout = new VerticalLayout();
        layout.setMargin(true);
        setContent(layout);

        timeLabel = new Label(getTime());

        refresher = new Refresher();
        refresher.setRefreshInterval(500);
        refresher.addListener(new RefreshListener(){
            @Override
            public void refresh(Refresher source) {
                timeLabel.setValue(getTime());
            }
        });
        addExtension(refresher);        

        layout.addComponent(timeLabel);

    }

    public String getTime(){
        DateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
        Date date = new Date();
        String d = dateFormat.format(date);
        return d;
    }

}

Answer 2

I Had the same exact problem and I found out how to solve it. I didn't know about the custom widgetset. It's necessary to add a reference to web.xml like this:

<init-param>
    <param-name>widgetset</param-name>
    <param-value>com.mypackage.AppWidgetSet</param-value>
</init-param>

Hope helps somebody