README for Jabber functionality in Aubit 4gl
	--------------------------------------------

This is basic IM (Instant Messaging), middleware and XML
parsing/generating functionality as part of Aubit 4lg compiler,
implemented using IksEmEl library. You can send and receive messages
to/from other Jabber clients (and ICQ, AIM, MS Messenger, SMS, email ...
anything supported in your Jabber server and his gateways, of course
including other Aubit programs), to humans using Jabber clients, or other
programs, including other Aubit 4gl programs.

What is it good for:
--------------------

We already have RCP in Aubit, but this RCP implementation is usable only
for talking between Aubit programs; and on LAN, it's just not good for
Internet. No talking to humans, no XML, and program you are "talking" to
must be running.

With JAM (Jabber as Middleware), you can do things like notify the user
when some condition arises (like, report is finished, expense report is
waiting for your approval) without the need to have program running on
your screen. OK, you can send email to do that, but with Jabber, you can
_reply_ too. For instance, you can click on predefined choices in Jabber
message, and send waiting report to printer, or to someone else.

Using IksEmEl, you can also create and send XML files, meaning you can
send fully formatted data, exchange arrays between programs, send HTML XML
formatted pages, output XML formatted files from 4gl programs...

And Jabber takes care of queuing (if other party is not on-line)
encryption, firewalls, routing etc. All you need to know is Jabber ID if
your correspondent, just like with email.

To me, Jabber is more then XML-RPC, since it can talk to humans, and many
more clients then RPC-XML can.  It can perform more/most tasks XML-RPC
can. But it is not SOAP.

Where are we:
-------------

Code is in tools/jabber.

There are currently no language bindings, just function calls.

This very early stage, only send and receive is working, with not much
error checking, in one word, early Alpha code, or maybe more like proof of
concept code. I tried to do much more, based on JabberX client
(http://sourceforge.net/projects/jabber-x), but failed miserably because
of sometimes strange (to me anyway) inner workings of Jabber protocol,
abandoned a lot of code, and started from scratch directly on top of
IksEmEl libraries. I consider this more my fault, then the fault of Jabber
protocol or IksEmEl libraries - For Jabber, natural state is to have only
one thread. For 4GL app, this is not too friendly approach.

Now what we have is very basic handling of Jabber functionality
(lib4glim.c) and a little 4gl test program (test_im.4gl) in /tools/jabber.

To work, this require IksEmEl library installed on your system:

http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/jabber-x/iksemel/

You will have to get it from CVS, since I did not find binaries anywhere.

To try it:
-----------

	cd to $AUBITDIR/tools/jabber,
	CHANGE LINES 23-28 IN test_im.4gl !!!!!!!

		let IM_USER 	= "andrejipaq3@jabber.org"
		let IM_PASS 	= "mysecretpassword"
		call chat("andrej@jabber.org")

	You don't want to send all your messages to me!
	(You will need 2 Jabber accounts: one to use for 4gl program, and
	another to talk to.)

	type "make",
	and then "test_in.4ae"

More information about Jabber:
------------------------------

www.jabber.org
www.jabbercentral.org

Questions:
----------

* Do you guys like/need this kind of functionality? Better ways? Ideas?

* I need a 4gl language bindings for this; I was looking at syntax used
for RCP in Aubit, but I don't thing this is a good fit. How about:

	SEND "my message" TO "andrej@jabber.org" USING "somebody@jabber.com"
	WITH "mypassword"
	RECEIVE INTO my_charvar [charvar_from,] [charvar_when] [ FROM
	"somebody@jabber.com" ]

There will be some more needed later, like:

	SEND PRESENCE ...
	SUBSCRIBE PRESENCE ...
	GET ROOSTER
	... and more ...

Suggestions?

Credits:
---------

Some of examples for writing this code was contributed by Bernhard R. Link
(brl@pcpool00.mathematik.uni-freiburg.de). Here is what he say:

> Please note, that this is not that simple, as it interferes a littel bit
> with the way the jabber-protocoll is build. An message may result in
> some results, like status codes or the like, but it is hard to say which
> time you are finished.
>
> I have some time ago started to write a program for iksemel
> for it bases on jabber, I will attach it. Please change the
> accountsnames, that are partly still added to it and be warned, that
> it is far from complete...
>
> Hochachtungsvoll,
> 	Bernhard R. Link

Yours, Andrej Falout, http://www.falout.com/disclaimer.html