But Jason is exactly right, to be precise in a time-zone-spanning app, you have to say come to my home at 4pm PST. GWT isn't doing anything magic or secret here in conversion, a Date is really a 64 bit number representing the milliseconds since 1970, in GMT. Your local machine then converts supplies the proper locale offset to the Date class, which gives you the local time corresponding to that number. The number itself is never changed.
Perhaps a better solution that would better represent what you seem to want, would be to keep the intended time zone offset along with the actual date - maybe extend Date to do this. So Joe in Oregon says meet me on Monday at 4pm, use date.getTimezoneOffset() to see what time zone this appointment is intended to be in. Store it in the database and everything. When Jane in NYC retrieves it, you can show it in her time (7pm), or in "Oregon local" time by simply adding the difference in offsets. This gives you the benefit of storing the date in a Timezone neutral fashion as is natural and correct to do, but still be able to display it as the time in the original locale. jk On Oct 17, 3:44 pm, sim123 <[EMAIL PROTECTED]> wrote: > Thanks for response Jason but what about dates, I am setting my > birhtday as today's date and somebody who is in different timezone, > GWT does conversion of birthdate (one day ahead or one day late), for > example if you set any date to be 10-15-2008 you will see same date as > either 10-14-2008 or 10-13-2008 respective to the server's time zone, > is it expected!! > > Another case is I sent an invite saying come to my home this monday at > 4:00 pm, if you are in different time zone you will see same thing as > come to my home on this Monday at 7:00 pm (as GWT did Time > conversion), is it expected too!! > > I think this is the data which is being converted and any program > should not play with user's data, GWT is doing this conversion then to > without any documentation, even if it is expected behavior, it should > be documented and there should be some way to disable this auto > conversion. I don't think passing Strings back and forth would be a > good idea, if I have Date object inside a map/list i need to traverse > through that list/map convert this date into String and return it to > client where client does same thing again, I can not construct a > String right from the beginning as database is returning me Date and > there could be so many different problems with different approaches, I > would prefer to write my own custom serializers in this case, can you > or anyone please tell me what is the problem with the serializer I > mentioned in my previous post? > > Thanks > > On Oct 18, 9:08 am, Jason Essington <[EMAIL PROTECTED]> wrote: > > > Of course this is expected behavior! When you are talking about time, > > that time is relative to your location. Just because it is noon where > > you are, doesn't mean it is noon where I am. > > > If you are in New York, and post a schedule to your server that > > indicates that you will be having a conference call at 4pm, when your > > associate in LA pulls up the schedule, you don't want it to say 4pm, > > you want it to say Noon, otherwise you'll miss each other by 4 hours. > > And what about your partners in India? you don't want them to have to > > guess at what time zone you set that schedule in, then try to figure > > the offset on their own. > > > If you don't want to take into account timezones when passing date/ > > time back and forth between the server, simply serialize the data > > yourself to something that doesn't include time zones ... like a > > string "Jan 28, 2008 1:45pm" > > > -jason > > > On Oct 17, 2008, at 12:56 PM, sim123 wrote: > > > > Oh!! so no one knows is it the expected behavior? Or it could be > > > changed? Can any one please suggest that creating custom serializers > > > for java classes is a good idea or not and what could be the pros and > > > cons of this approach? > > > > Thanks. > > > > On Oct 18, 5:46 am, "Manuel Carrasco" <[EMAIL PROTECTED]> > > > wrote: > > >> I had the same problem passing java.util.Date from client to > > >> server. When > > >> they use different TZ, dates differ. Eventually I use String > > >> representation > > >> of the dates for client/server dialog, and use DateTimeFormat for > > >> transformations. > > > >> On Fri, Oct 17, 2008 at 6:36 PM, Tahir Akhtar > > >> <[EMAIL PROTECTED]>wrote: > > > >>> There is another issue related to serialization of dates that can > > >>> occur due to emulation of long with double in generated JavaScript. > > > >>> See: > > > >>>http://groups.google.com/group/Google-Web-Toolkit/browse_thread/threa > > >>> ... > > > >>> On Oct 17, 2:57 am, sim123 <[EMAIL PROTECTED]> wrote: > > >>>> Can some one please reply to my post, please!!! > > >>>> I just want to know if it is expected behavior, and if it is can I > > >>>> create custom serializer for not doing this conversion for > > >>>> example I > > >>>> tried changing Date_CustomFieldSerializer .java's code in to GWT > > >>>> source to be > > > >>>> public static void deserialize(SerializationStreamReader > > >>>> streamReader, > > >>>> Date instance) { > > >>>> // No fields > > >>>> } > > > >>>> public static Date instantiate(SerializationStreamReader > > >>>> streamReader) > > >>>> throws SerializationException { > > >>>> Date d = Date.valueOf(streamReader.readString()); > > >>>> return d; > > >>>> } > > > >>>> public static void serialize(SerializationStreamWriter > > >>>> streamWriter, > > >>>> Date instance) throws SerializationException { > > >>>> streamWriter.writeString(instance.toString()); > > >>>> } > > > >>>> and it worked, it is not doing any conversion for Date, however I > > >>>> don't want to play with real GWT's code so just wondering if I > > >>>> could > > >>>> write custom serializer for java fields? > > > >>>> I would really appreciate any help. Thanks > > > >>>> On Oct 16, 8:28 pm, sim123 <[EMAIL PROTECTED]> wrote: > > > >>>>> I looked into serialization code for Date/Time and Timestamp in > > >>>>> com.google.gwt.user.client.rpc.core.java.sql package, it seems > > >>>>> that > > >>>>> these classes are cause of time zone conversion, is that so and > > >>>>> is it > > >>>>> expected behavior?? Some one please help me. > > > >>>>> Thanks. > > > >>>>> On Oct 16, 6:21 pm, sim123 <[EMAIL PROTECTED]> wrote: > > > >>>>>> Hello, > > > >>>>>> I noticed strange behavior of GWT serialization when handling > > >>>>>> Date/ > > >>>>>> Time/Timestamp values. When client and servers are in different > > >>>>>> time > > >>>>>> zones like server is in GMT and client is running in PST time > > >>>>>> zone, > > >>>>>> RPC does timezone conversion for Date/Time and Timestamp, I am > > >>>>>> not > > >>>>>> sure if this is acceptable behavior and if it is then is there > > >>>>>> a way > > >>> I > > >>>>>> could disable this conversion. Here is the example > > >>>>>> public class DateTest implements EntryPoint { > > > >>>>>> public void onModuleLoad() { > > > >>>>>> Button b = new Button(); > > > >>>>>> b.addClickListener(new ClickListener() { > > > >>>>>> public void onClick(Widget sender) { > > >>>>>> DateServiceAsync dateService = > > >>> DateService.Util.getInstance(); > > >>>>>> dateService.getTimestamp(new > > >>> AsyncCallback<Timestamp>(){ > > > >>>>>> public void > > >>> onFailure(Throwable caught) { > > >>>>>> // TODO > > >>> Auto-generated method stub > > > >>>>>> } > > > >>>>>> public void > > >>> onSuccess(Timestamp result) { > > >>>>>> TextBox tBox = > > >>>>>> new > > >>> TextBox(); > > > >>> tBox.setText(result.toString()); > > > >>> RootPanel.get().add(tBox); > > >>>>>> } > > > >>>>>> }); > > >>>>>> } > > > >>>>>> }); > > >>>>>> RootPanel.get().add(b); > > > >>>>>> } > > > >>>>>> Service Implementation > > > >>>>>> public class DateServiceImpl extends RemoteServiceServlet > > >>>>>> implements > > >>>>>> DateService { > > > >>>>>> public Timestamp getTimestamp() { > > >>>>>> Timestamp t = new > > >>> Timestamp(System.currentTimeMillis()); > > >>>>>> System.out.println("timestamp at server" + t); > > >>>>>> return t; > > >>>>>> } > > > >>>>>> If server is running on GMT Time and client browser is in > > >>>>>> different > > >>>>>> timezone GWT does conversion (even for Date and Time types). > > >>>>>> Please suggest. Thansk for all the help and support. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/Google-Web-Toolkit?hl=en -~----------~----~----~----~------~----~------~--~---
