Wicket AjaxCheckBox

Question : how to Ajax-ify a CheckBox in Wickets ?

Answer : need to specialize the AlaxCheckBox class.


Details :

Step #1 : consider these Wicket class attributes :

private static Boolean isAuto = false;
private static final String WICKET_CB = "autoCheck";
private IModel<Boolean> autoCheckModel = new Model<Boolean>(isAuto);
private AutoRefreshCheckBox autoCheck = new AutoRefreshCheckBox(WICKET_CB, autoCheckModel);

Step #2 : the customized AjaxCheckBox is added within the constructor of this same Wicket class :

add(autoCheck);

Step #3 : specialized AjaxCheckBox class body

private class AutoRefreshCheckBox extends AjaxCheckBox
{
    public AutoRefreshCheckBox(final String id, IModel<Boolean> model)
    {
        super(id, model);
    }
    
    /**
    * Says whether or not the "AutoRefresh" mode is enabled
    */
    public Boolean isChecked()
    {
        final String value = getValue();
        if (value != null)
        {
            try
            {
                return Strings.isTrue(value);
            }
            catch (StringValueConversionException e)
            {
                return false;
            }
        }

        return false;
    }
    
    @Override
    protected synchronized void onUpdate(AjaxRequestTarget target)
    {
        long period = 0L;
        
        isAuto = isChecked();
        autoCheckModel.setObject(isAuto);
        target.addComponent(refreshBtn);
        if (isAuto)
        {
            period = Long.valueOf(periodField.getValue()) * TO_MS;
            // might be completed (e.g.: overall page refresh)
        }
        else
        {
            // might be completed (e.g.: period = PERIOD_MONITOR_OFF;)
        }
  
        // might be completed (e.g.: other components update)
    }
}