[Gambas-user] Strange problem with Date Time and ValueBox

[Richard]

On Wednesday 12 March 2008 00:31:05 Richard wrote:
> On Tuesday 11 March 2008 21:55:51 Richard wrote:
> > On Tuesday 11 March 2008 12:42:44 Benoit Minisini wrote:
> > > On samedi 8 mars 2008, Richard wrote:
> > > > I have a little program which I wrote for the last winter Ashes tour.
> > > > It provides a way to do timer controlled recordings from radio
> > > > programmes streamed by the BBC and played by Helixplayer.
> > > >
> > > > I have tinkered with it from time to time to bloat its feature set
> > > > and keep it up to date with various key changes to the Gambas2
> > > > environment. The current working version is in use recording each
> > > > day's play in the 3 test series under way in New Zealand. It runs on
> > > > Gambas2 v2.0 with a backported bug-fix for the date chooser control
> > > > which Benoit kindly provided.
> > > >
> > > > I have always found plenty to confuse me when handling dates and
> > > > times in Gambas but having converted from my own customised versions
> > > > of the DateBox and TimeBox controls to the new ValueBox control I had
> > > > reviewed the date and time handling code to make sure I am not doing
> > > > any redundant conversions.
> > > >
> > > > Something I changed recently introduced a bug to the
> > > > store-recall-timer-settings process. A date and time entered as
> > > > {02/03/2008 15:45:11} is changed, when it is recalled from a storage
> > > > array, to {02/03/2008 00:41:26}.
> > > >
> > > > A lot of time spent tracing through my over-complex logic eventually
> > > > located the probable "cause" in part of the code which restores a
> > > > previously stored collection of settings.  The relevant code snippet
> > > > is:
> > > >
> > > >         'Timer tab controls
> > > >         LineRecord.StartDateChooser.Value =
> > > > Date(records[ix].Start_Time) LineRecord.StartDateBox.Value =
> > > > Date(records[ix].Start_Time) 'Do not trigger selected Change events
> > > >         LineRecord.INC_autoset
> > > >         LineRecord.HourTimeSet.Value = Hour(records[ix].Start_Time)
> > > >         LineRecord.MinuteTimeset.Value =
> > > > Minute(records[ix].Start_Time) LineRecord.SecondTimeSet.Value =
> > > > Second(records[ix].Start_Time) 'Re-enable selected Change events
> > > >         LineRecord.DEC_autoset
> > > >         'LineRecord.StartTimeBox.Value = Time(records[ix].Start_Time)
> > > >         LineRecord.StartTimeBox.Value = (records[ix].Start_Time)
> > > >
> > > > In the last two lines the version commented out is the line which
> > > > introduces the incorrect time. The line below works just fine. The
> > > > records array is an array of objects of Class Recording. The
> > > > Recording.Start_Time property is a Date value with both date and time
> > > > parts.
> > > >
> > > > Until this week the first two lines, and the penultimate, simply
> > > > assigned the whole date/time value to the DateChooser, StartDateBox
> > > > and the StartTimeBox. I decided to make it more "correct" after
> > > > reading about the Date and Time conversion functions. Only the
> > > > Time(date_variable) line is "wrong". Reverting to the old sloppy way
> > > > fixes the problem.
> > > >
> > > > Here's the question: Has anyone come across a similar problem in
> > > > date/time handling? I have tried replicating the problem in
> > > > independent code with no success.
> > > >
> > > >
> > > > Richard
> > >
> > > Can you provide the full source code?
> >
> > Yes, can do, but it isn't pretty. The source archive is currently 640k,
> > but that includes a lot of clutter in the project img folder.
> >
> > > And can you use DEBUG or PRINT
> > > instruction to the prints the value of records[ix].Start_Time before
> > > assigning it?
> >
> > I found the rogue value while stepping through the code using the
> > debugger and the Watch pane.
> >
> > > Regards,
> >
> > I have also tried to replicate the problem in stand-alone code (a test
> > project) which simply does the same logical things with date and time
> > values, but that worked perfectly; just the way you would expect. My
> > guess at this stage is that I have managed to create an inconsistency
> > somewhere. The observation that nobody else has come across the same snag
> > would seem to confirm that the bug is mine all mine!
> >
> > I'll do some more searching now that the latest modifications to the
> > application are working and I'll get back to you if I need more help.
> >
> > Richard
> >
> >
> >
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>
> OK, I have found another code sequence which works.
>
> I had scattered a few DEBUG statements around sections of code which read
> and write the start date/time value and noticed that where the problem
> value appears, my procedure reads the Recording.Start_Time property lots of
> times.
>
> Apart from any other consideration, this seemed a bit wasteful of processor
> power so I changed the procedure to read the property value once into a
> local variable and then use the local value for extracting Date, Hour,
> Minute, Second and Time values.
>
> This has had the interesting side effect of avoiding the bug. See the code
> snippet below (compared to the same sequence copied in my first message):
>
>         'Timer tab controls
>         'DEBUG ix; ">=";; records[ix].Start_Time;;
> Date(records[ix].Start_Time);; Time(records[ix].Start_Time)
>         'DEBUG CFloat(records[ix].Start_Time);;
> CFloat(Date(records[ix].Start_Time));; CFloat(Time(records[ix].Start_Time))
>         StartTime = records[ix].Start_Time
>         LineRecord.StartDateChooser.Value = Date(StartTime)
>         LineRecord.StartDateBox.Value = Date(StartTime)
>         'Do not trigger selected Change events
>         LineRecord.INC_autoset
>         LineRecord.HourTimeSet.Value = Hour(StartTime)
>         LineRecord.MinuteTimeset.Value = Minute(StartTime)
>         LineRecord.SecondTimeSet.value = Second(StartTime)
>         'Re-enable selected Change events
>         LineRecord.DEC_autoset
>         LineRecord.StartTimeBox.Value = Time(StartTime)
>         'LineRecord.StartTimeBox.Value = (records[ix].Start_Time)
>
> This just gets more and more interesting, but it is late now. I'll explore
> further tomorrow.
>
> Richard
>
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It has happened again in the same code sequence but with a different 
date/time. The time should have been 21:00:00, but the Time() function reads 
it as 00:41:26, the same wrong value. 

I still think it must be something not quite right with my program rather than 
a problem with the Time() function. I have a trimmed down version of the 
project - all the original code is present, just some xcf files deleted from 
the img folder - which has some tell-tale DEBUG statements in the right place 
to show what works and what doesn't.  Nevertheless it is still about 
230kbytes. Is that too big to post here?

Richard