[Gambas-user] gb3: sending variable of date datatype over UDP

[Benoît Minisini]

> Any reason this code wouldn't work?
> 
> ' Server-side:
> 
> UDP_Write_56(pip[p], pport[p], tsid[p], Date)
> 
> Public Sub UDP_Write_56(ip As String, port As Integer, id As Byte,
> serverdate As Date)
> 
>    ' Send "date update" transaction to specified IP address and port
> over UDP.
> 
>    ' Define target's IP address and port.
>    udp.TargetHost = ip
>    udp.TargetPort = port
> 
>    ' Send the transaction.
>    udp.Begin
>      Write #udp, id As Byte
>      Write #udp, 56 As Byte
>      Write #udp, serverdate As Date
>    udp.Send
> 
> End
> 
> ' Client-side:
> 
> ' tsdata = 8-byte date string from received UDP packet
> worlddate = Date@(Convert.Reverse(tsdata))
> 
> Public Function Reverse(data As String) As String
> 
>    ' Reverse the order of the passed bytes.
> 
>    ' General declarations.
>    Dim counter As Byte     ' Generic counter.
>    Dim length As Byte      ' Length of the passed string.
>    Dim reversed As String  ' The reversed string.
> 
>    ' Reverse the string
>    length = Len(data)
>    For counter = length To 1 Step -1
>      reversed = reversed & Mid$(data, counter, 1)
>    Next
> 
>    ' Return the reversed value.
>    Return reversed
> 
> End
> 
> If I send and receive it as a float it works, but doesn't give me the
> time (date only). If I send/receive it as a date it gives me a totally
> wrong value, such as "10883/26232/-22744 285:08:28". Combinations of the
> two give me different incorrect values.
> 
> This technique of reversing bytes received as UDP packets into different
> datatypes has worked for everything but the date datatype. Any ideas why
> this is? I need the clients to know what time it is on the server so
> they can render day/night cycles appropriately.

Date are sent as two 32-bits integers. So you must not reverse the all string, 
but each four bytes part indepently.

Regards,

-- 
Benoît Minisini