How to limit the available Date ranges with the com.google.gwt.user.datepicker.client.DateBox

Question

I need to limit what Dates a user can pick from the com.google.gwt.user.datepicker.client.DateBox.

I can't seem to figure out how to limit the min Date so they can't pick past dates.

If I can't do this with com.google.gwt.user.datepicker.client.DateBox is there an alternative DateBox widget that will allow me this kind of flexibility?

Natelson

Answer 1

Based on the suggestions I received, here is what I came up with that works on limiting the selectable dates to only the current day and after. This works on GWT 2.1.1

final DateBox dateBox = new DateBox();
dateBox.addValueChangeHandler(new ValueChangeHandler<Date>()
{
    @Override
    public void onValueChange(final ValueChangeEvent<Date> dateValueChangeEvent)
    {
        if (dateValueChangeEvent.getValue().before(today()))
        {
            dateBox.setValue(today(), false);
        }
    }
});
dateBox.getDatePicker().addShowRangeHandler(new ShowRangeHandler<Date>()
{
    @Override
    public void onShowRange(final ShowRangeEvent<Date> dateShowRangeEvent)
    {
        final Date today = today();
        Date d = zeroTime(dateShowRangeEvent.getStart());
        while (d.before(today))
        {
            dateBox.getDatePicker().setTransientEnabledOnDates(false, d);
            d = nextDay(d);
        }
    }
});

And for completeness here are the static helper methods for manipulating the dates:

private static Date today()
{
    return zeroTime(new Date());
}

/** this is important to get rid of the time portion, including ms */
private static Date zeroTime(final Date date)
{
    return DateTimeFormat.getFormat("yyyyMMdd").parse(DateTimeFormat.getFormat("yyyyMMdd").format(date));
}

private static Date nextDay(final Date date)
{
    return zeroTime(new Date(date.getTime() + 24 * 60 * 60 * 1000));
}

Natelson

Great answer, but I'd like to address a small bug in the onShowRangeHandler method. The loop should also be bounded to the end range (otherwise throws silent dev-environment assertion exceptions) ` final long endTime = event.getEnd().getTime(); while (d.before(today) && d.getTime() <= endTime) { dateBox.getDatePicker().setTransientEnabledOnDates(false, d); d = nextDay(d); } ` – Fusain

Also, during a transition from Daylight Time to Standard Time, this code will enter into an infinite loop – Replication

Please use com.google.gwt.user.datepicker.client.CalendarUtil in order to add one day to the current date: CalendarUtil.addDaysToDate (d, 1);. This will also work for changes from daylight saving to standard time and vice versa. And you do not have to cope with the time parts! – Stipendiary

Answer 2

I am guessing here but you may need to use the addValueChangeHandler. An example:

datebox.addValueChangeHandler(new ValueChangeHandler<Date>() {
    public void onValueChange(ValueChangeEvent<Date> event) {
        Date date = event.getValue();
        if (date.before(new Date())) {
         fromDatePicker.setValue(new Date());
        }
    }
});

Here when a user somehow selects a date that is in the past, it will auto set it to current date (or whatever fits your needs).

Polynesia

I would rather just disable any dates in the past and avoid the possibility of them picking one at all. Is there a way to disable the actual clickable dates in the calendar widget? – Natelson

this is on the right track, but it is inherently flawed. Since new Date() has time associated with it, the date.before(new Date()) will always fail. I had to strip off the time to get this approach to work. Now I can reset the date to today, but am still looking for a way to disable the past dates completely. – Natelson