Re: [Dynapi-Help] Simple communication questions...

[Leif W <war...@us...>]

I was thinking of how to approach this problem a while back (for the case=
 of
a simple online cardgame) but never came to anything concrete.  However, =
I
did remember playing with some script (it was in Perl but you could use a=
ny
language) which acts as a server-push, but it only works for Mozilla, not
IE, and not tested in Opera or Safari.  So, if you want a true client-ser=
ver
model with bidirectional communication I guess you're best off coding a J=
ava
applet for the browser, and whatever language specialized server with you=
r
own protocol.

Anyways here's the example code I was using.  Also, I was testing on an
Apache server and the script would not work unless the filename began wit=
h
"nph-" which stands for non-parsed headers.

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
BEGIN - Perl script
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
#! /usr/bin/perl -w
use strict;

use CGI qw/:standard :push/;
use CGI::Carp 'fatalsToBrowser';

$CGI::POST_MAX =3D 1024 * 1024; # max 1M posts
$CGI::DISABLE_UPLOADS =3D 1;  # no uploads
$| =3D 1;

print multipart_init(-boundary=3D>'----here we go!');

foreach (0 .. 4) {
    print multipart_start(-type=3D>'text/plain'),
          "The current time is ",scalar(localtime),"\n";
    if ($_ < 4) {
            print multipart_end;
    } else {
            print multipart_final;
    }
    sleep 1;
}

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
END - Perl script
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D

As you can see, most of the actual server-push code is handled by the CGI
Perl Module.  So just taking a quick peek inside to show the relevent bit=
s
of raw HTTP and HTML tricks used, or just using telnet or wget to fetch f=
rom
the server.

Headers: (first three added by Apache, last one added by the script)

HTTP/1.0 200 OK
Server: Apache/2.0.47 (Unix) mod_ssl/2.0.47 OpenSSL/0.9.7c DAV/2
PHP/4.3.4RC1
Date: Tue, 14 Oct 2003 13:39:48 GMT
Content-Type: multipart/x-mixed-replace;boundary=3D"----here we go!"

Content:

WARNING: YOUR BROWSER DOESN'T SUPPORT THIS SERVER-PUSH TECHNOLOGY.
------here we go!
Content-Type: text/plain

The current time is Tue Oct 14 09:39:48 2003

------here we go!
Content-Type: text/plain

The current time is Tue Oct 14 09:39:49 2003

------here we go!
Content-Type: text/plain

The current time is Tue Oct 14 09:39:50 2003

------here we go!
Content-Type: text/plain

The current time is Tue Oct 14 09:39:51 2003

------here we go!
Content-Type: text/plain

The current time is Tue Oct 14 09:39:52 2003

------here we go!--
WARNING: YOUR BROWSER DOESN'T SUPPORT THIS SERVER-PUSH TECHNOLOGY.



----- Original Message -----=20
From: "Raymond Irving" <xw...@ya...>
To: <dyn...@li...>
Sent: Monday, October 13, 2003 10:27 AM
Subject: Re: [Dynapi-Help] Simple communication questions...


>
> See below:
>
> --- Clemens Eisserer <Lin...@we...> wrote:
> > Hi again!
> >
> > I=B4m currently thinking about writing a simple
> > JS-Chat, so that the chat doent need to reload
> > always when
> > new messages recieve.
> > The problem is, that the server should connect to
> > the client, which is not possible as far as I know,
> > this
> > means the client has to use possling and aks all x
> > seconds the server for new messages.
> >
> > 1.) Is there no other was to do this than polling?
>
> Not that I know of
>
> > 2.) These are the only polling-ideas I had:
> > * Blocking soda-rpc function. Blocks till messages
> > are on server. (Problem with blocking - no events
> > etc?)
> > * Non-Blocking soda-rpc function. Returns -1 if
> > nothing is there...
> >
> > Is the blocking version possible, or will it cause
> > the application to hand in the poll-loop. This is a
> > problem
> > in my eyes since JS hasnt support f=FCr Multithreading
> > :(
>
> Using synchronous GET or post will cause the app to
> wait until the server returns a response.
>
>
> > Does anybody have better ideas, I=B4m not really happy
> > with my stuff..
>
> In the future there might be an easier method
>
> --
> Raymond Irving
>
> > lg Clemens
> >
> > PS1: How hard would it be to adopt dynapi to
> > knoqueror? (only because it interrests me why so
> > many
> > examples dont work..)
> > PS2: Dynapi is great!
> >
> >
>
_________________________________________________________________________=
___
__
> > Zwei Mal Platz 1 mit dem jeweils besten
> > Testergebnis! WEB.DE FreeMail
> > und WEB.DE Club bei Stiftung Warentest!
> > http://f.web.de/?mc=3D021183
> >
> >
> >
> >
> -------------------------------------------------------
> > This SF.net email is sponsored by: SF.net Giveback
> > Program.
> > SourceForge.net hosts over 70,000 Open Source
> > Projects.
> > See the people who have HELPED US provide better
> > services:
> > Click here: http://sourceforge.net/supporters.php
> > _______________________________________________
> > Dynapi-Help mailing list
> > Dyn...@li...
> >
> https://lists.sourceforge.net/lists/listinfo/dynapi-help
>
>
> __________________________________
> Do you Yahoo!?
> The New Yahoo! Shopping - with improved product search
> http://shopping.yahoo.com
>
>
> -------------------------------------------------------
> This SF.net email is sponsored by: SF.net Giveback Program.
> SourceForge.net hosts over 70,000 Open Source Projects.
> See the people who have HELPED US provide better services:
> Click here: http://sourceforge.net/supporters.php
> _______________________________________________
> Dynapi-Help mailing list
> Dyn...@li...
> https://lists.sourceforge.net/lists/listinfo/dynapi-help
>
>