Abhi's Weblog » XMPP

JAXL library – List of available hooks for various XMPP events

Abhinav Singh — Wed, 06 Apr 2011 22:16:57 +0000

Jaxl 2.x provides an event mechanism using which developers can register callbacks for various xmpp events inside their application code. This blog post will demonstrate how to register callbacks for required xmpp events and go through a list of all available hooks. Finally, we will discuss parameters that are passed to called back methods by Jaxl core.

Registering callback on XMPP events
Applications can register callback for various XMPP events. Jaxl core will then callback application methods (with 2 parameters) every time associated XMPP event occurs. Shown below are some sample examples for registering callbacks.

When application callback’d method is a function:

function postAuth($payload, $jaxl) {

}
$jaxl->addPlugin('jaxl_post_auth', 'postAuth');

When application callback’d method is a public static method of a class:

class MyXMPPApp {
    public static function postAuth($payload, $jaxl) {

    }
}
$jaxl->addPlugin('jaxl_post_auth', array('MyXMPPApp', 'postAuth'));

When application callback’d method is a public method inside a class:

class MyXMPPApp {
    function postAuth($payload, $jaxl) {

    }
}
$MyXMPPApp = new MyXMPPApp();
$jaxl->addPlugin('jaxl_post_auth', array($MyXMPPApp, 'postAuth'));

In all the above examples jaxl_post_auth is one of the available hook for registering callbacks.

List of available hooks
Below is a complete list of available hooks in order of their occurrence within a Jaxl instance life cycle:

Hooks for events related to instance connection and authentication steps in various modes:

jaxl_post_connect
jaxl_get_auth_mech
jaxl_get_facebook_key
jaxl_post_auth_failure
jaxl_post_auth
jaxl_post_handshake
jaxl_pre_shutdown
jaxl_post_disconnect
jaxl_get_empty_body

Hooks for events related to XMPP stream and stanza’s:

jaxl_get_stream_error
jaxl_get_presence
jaxl_get_message
jaxl_get_iq_get
jaxl_get_iq_set
jaxl_get_iq_error
jaxl_send_message
jaxl_send_presence

Hooks for events related to reading/writing of XMPP packets and internal packet routing:

jaxl_get_xml
jaxl_send_xml
jaxl_send_body
jaxl_pre_handler
jaxl_post_handler

TO-DO: Update when every hook is called inside your application life cycle and list of parameters passed for each callback. As of now you can var_dump($payload); inside your callback method.

PHP Code, Setup and Demo of Jaxl boshchat application

Abhinav Singh — Tue, 17 Aug 2010 10:13:42 +0000

Jaxl 2.0 bosh support allow web developers to write real time web applications within minutes, without having any pre-requisite knowledge about the XMPP protocol itself. In this blog post, I will walk you through setup and demo of an XMPP based web chat application using Jaxl library.

Get the code
Follow the following steps to download and install this sample web application on your systems:

Clone the development branch of Jaxl library
```
root@ubuntu:~/git# git clone git@github.com:abhinavsingh/JAXL.git
root@ubuntu:~/git# cd JAXL/
root@ubuntu:~/git/JAXL#
```
If you are not familiar with git, simply visit JAXL@github, click Download Source and extract under ~/git/JAXL directory on your system
Once inside Jaxl source directory, build the latest development package
```
root@ubuntu:~/git/JAXL# ./build.sh
building...
```

Install Jaxl library (view installation detail and options)

root@ubuntu:~/git/JAXL# ./build.sh install
uninstalling old package...
installing...

Setup web chat application
Jaxl library is default installed under /usr/share/php/jaxl folder. Application code for our web chat application can be found under /usr/share/php/jaxl/app/boshchat folder.

Follow these steps to setup web chat application on your system:

I assume you have http://localhost/ configured on your local web server and it runs out of /var/www folder. Create following symlinks:

root@ubuntu:~/git/JAXL# cd /var/www
root@ubuntu:/var/www# ln -s /usr/share/php/jaxl/app/boshchat/boshchat.php index.php
root@ubuntu:/var/www# ln -s /usr/share/php/jaxl/app/boshchat/jaxl.ini jaxl.ini
root@ubuntu:/var/www# ln -s /usr/share/php/jaxl/env/jaxl.js jaxl.js
root@ubuntu:/var/www# ln -s /usr/bin/jaxl jaxl.php

Edit/Remove #!/usr/bin/env php inside jaxl.php if it causes any problem on your system.

Open and edit jaxl.ini

define('JAXL_BOSH_COOKIE_DOMAIN', false);

I assume you have access to XMPP over Bosh enabled jabber server. Ejabberd users can verify this by hitting http://localhost:5280/http-bind in the browser
Open and edit index.php
```
define('BOSHCHAT_ADMIN_JID', 'admin@localhost');
```
All messages sent using this web chat application will be routed to BOSHCHAT_ADMIN_JID

Ready for the demo
To run this example web chat application, visit http://localhost in your browser window. Enter a username/password already registered on your jabber server and press connect.

Login as BOSHCHAT_ADMIN_JID using a desktop client, so that you can receive messages sent from the browser on your desktop client.

Below is a screenshot when I logged in as “abhinavsingh” from browser and BOSHCHAT_ADMIN_JID was set to “jaxl@jaxl.im”:

Releasing Jaxl 2.0 – Object oriented XMPP framework in PHP

Abhinav Singh — Mon, 02 Aug 2010 22:41:07 +0000

After months of restructuring the Jaxl library, I am pleased to announce Jaxl 2.0, an object oriented XMPP framework in PHP for developing real time applications for browsers, desktops and hand held devices.

What’s new in Jaxl 2.0?

A lot of structural changes has been done from the previous version to make it more scalable, robust, flexible and easy to use
Library now provides an event mechanism, allowing developers to register callbacks for various xmpp events in their application code
Use integrated BOSH support to write real time web applications in minutes
More than 10 new implemented XMPP extensions (XEP’s) added
Development hosting moves to github, stable releases available at google code

Documentation for Jaxl users
Below is a list of getting started documentation for XMPP app developers:

Installation, Usage guide and Sample applications
Jaxl Core classes, available methods and directory structure
Writing your first command line bot using Jaxl
Facebook chat connect with X-FACEBOOK-PLATFORM using Jaxl
Code, Setup and Demo of Bosh chat application
Writing External Jabber Components in PHP using Jaxl library
Writing XMPP web applications using Jaxl in 5 minutes (coming soon)
Available hooks for various xmpp events (coming soon)
Migration guide for Jaxl 1.x users (coming soon)

Implemented XEP’s
A lot of new XEP’s has been implemented and packaged with Jaxl 2.0. Developers can use Jaxl event mechanism to implement new XEP’s without knowing the working of other core parts of the library.

Below is a list of released implemented XEP with Jaxl 2.0:

0004 – Data Forms
0030 – Service Discovery
0045 – Multi-User Chat
0050 – Ad-Hoc Commands
0085 – Chat State Notification
0092 – Software Version
0114 – Jabber Component Protocol
0115 – Entity Capabilities
0124 – Bosh Implementation
0133 – Service Administration
0119 – XMPP Ping
0202 – Entity Time
0206 – XMPP over BOSH
0249 – Direct MUC Invitation

Documentation for project contributors
For developers interested in contributing to the Jaxl project, here is a list of insight documentation to get you started:

Jaxl core workflow and architecture (coming soon)
How to implement new XMPP extensions using Jaxl (coming soon)

Useful Links
For live help and discussion join jaxl@conference.psi-im.org chat room

Introducing WP-Chat :: XMPP Chat plugin for WordPress

Abhinav Singh — Thu, 15 Jul 2010 21:25:05 +0000

WP-Chat plugin embeds Jaxl IM (Instant Messenger for the web) for wordpress blogs. It runs across all major browsers and built upon XMPP protocol. It is a hosted solution from Jaxl.im empowering real time communication between you and your site visitors. It expects no software or hardware pre-requisites from your site servers or users. Above all it’s free!

Overview:

Supports for all major browser including Firefox, Chrome, Safari and IE
Embeddable on all blogs, forums, personal, social and enterprise sites
Built using XMPP protocol (backbone for facebook and google chats)
Hosted dashboard for site admins and IM users
Pluggable and Skinnable using developer api
Connect with you desktop IM clients (e.g. Pidgin, PSI, …)

History:
In two of my previous post (Introducing MemChat and Jaxl BOSH Demo), I discussed and demoed a very early version of WP Chat plugin. In past 3 months, work has been done to make WP Chat generic enough so that it can be embedded across all kind of blogs, forums, social, personal and enterprise level websites. As of today, the product is named as “Jaxl IM (Instant Messenger for the web)” and made available as “WP-Chat” for the wordpress users.

Setting up ejabberd 2.1.x development environment on Ubuntu

Abhinav Singh — Wed, 31 Mar 2010 21:04:13 +0000

apt-get provide a convenient way of installing ejabberd on Ubuntu distributions. However, if you are an erlang developer and looking to write custom ejabberd modules, you might want to install ejabberd from the source code.

Checkout ejabberd source
To start with lets grab the ejabberd 2.1.x branch source code:

sudo apt-get install git-core
git clone git://git.process-one.net/ejabberd/mainline.git ejabberd
cd ejabberd
git checkout -b 2.1.x origin/2.1.x
cd src

Installing pre-requisites
Lets setup necessary pre-requisites before compiling ejabberd source code:

sudo apt-get install build-essential
sudo apt-get install automake autoconf
sudo apt-get install erlang erlang-manpages
sudo apt-get install libexpat1-dev zlib1g-dev libssl-dev

Compiling ejabberd source code
Compiling and installing is dead simple:

./configure
make
sudo make install

Setting up administration account
By now we have ejabberd server setup on our ubuntu box. Lets setup the admin account:

sudo ejabberdctl start
sudo ejabberdctl register admin localhost password
sudo vim /etc/ejabberd/ejabberd.cfg

Add following configurations if not already present:

{acl, admin, {user, "admin", "localhost"}}.
{loglevel, 5}. %% Log level while development

sudo ejabberdctl restart
Visit ejabberd admin panel: http://localhost:5280/admin
When prompted enter username as admin@localhost and the password you chose above while registering admin account

Resolving startup errors
You might see a few error reports in logs or elsewhere while starting ejabberd server:

/sbin/ejabberdctl: 340: cannot create //var/lock/ejabberdctl/ejabberdctl-1: Directory nonexistent

=ERROR REPORT==== 2010-03-29 21:53:03 ===
C(<0.995.0>:ejabberd_captcha:331) : The option captcha_cmd is not configured, but some module wants to use the CAPTCHA feature.

=INFO REPORT==== 2010-03-29 21:53:03 ===
I(<0.780.0>:ejabberd_rdbms:37) : ejabberd has not been compiled with relational database support. Skipping database startup.

Here is how you can resolve the above errors:

sudo mkdir /var/lock/ejabberdctl/ejabberdctl-1
Add following line in ejabberd.cfg
```
{captcha_cmd, "/lib/ejabberd/priv/bin/captcha.sh"}.
```
Replace /lib/ejabberd/priv/bin/captcha.sh with path to /ejabberd/tools/captcha.sh

Getting started with ejabberd development
Below are links to a few useful resources to get you started with erlang and ejabberd module development:

Erlang programming rules and conventions: http://www.erlang.se/doc/programming_rules.shtml
Erlang documentation: http://www.erlang.org/doc
Ejabberd module development wiki: http://www.process-one.net/en/wiki/ejabberd_module_development
Ejabberd documentation: https://support.process-one.net/doc/display/MESSENGER/ejabberd

JAXL BOSH Demo: IM chat client for all WordPress blogs

Abhinav Singh — Thu, 28 Jan 2010 20:53:30 +0000

Have you ever wished of a wordpress plugin capable of providing a facebook style chat bar on your blog post. In this blog post, I will lay down the details of how Jaxl‘s bosh support comes in handy for building such browser based real time application. Specifically, I will explain how I achieved building a plugin for my wordpress blog. If everything goes perfect over next few weeks, this plugin might be submitted in wordpress plugin’s directory.

Jaxl BOSH Support Framework
Jaxl BOSH support comprise of three main parts:

jaxl.jquery.js: JQuery extension written for Jaxl bosh support
jaxl4bosh.class.php: Connection manager in PHP
jaxl UI: Integrated UI framework for changing your application skin on the fly. Your application skin can be a simple facebook style chat bar (as on this page) or chesspark style whole html page

jaxl.jquery.js is responsible for initiating and maintaining a connection between the browser and the PHP connection manager. While jaxl4bosh.class.php implements the BOSH protocol and maintain a persistent connection with the jabber server.

jaxl.jquery.js provide a few basic methods like:

jaxl.connect: Call for initiating the connection
jaxl.sendMessage: Call for sending a message to other jid’s
jaxl.ping: Call to maintain the connection and gather any incoming data
jaxl.disconnect: Call for disconnecting

jaxl4bosh.class.php provide wordpress style filter/hooks which can be used to modify every incoming and outgoing messages.

jaxl_pre_connect: Call to perform initialization before jaxl connects to jabber server
jaxl_post_connect: Call to perform shutdown after jaxl is connected to jabber server
jaxl_send_message: Call to perform actions on outgoing messages from jaxl
jaxl_recv_message: Call to perform actions on incoming messages to jaxl
jaxl_send_presence: Call to perform actions on outgoing presence from jaxl
jaxl_recv_presence: Call to perform actions on incoming presence from jaxl
jaxl_pre_disconnect: Call to perform initialization before jaxl disconnects to jabber server
jaxl_post_disconnect: Call to perform shutdown after jaxl is disconnected to jabber server

Jaxl and WordPress
Using Jaxl bosh support require you to only edit the configuration file. Here are the config variables:

        // JAXL config
        define('JAXL_BOSH_HOST', 'localhost');
        define('JAXL_BOSH_SERVER', 'localhost');
        define('JAXL_BOSH_URL', 'http://localhost:7070/http-bind/');
        define('JAXL_ADMIN_JID', 'admin@localhost');

You can configure Jaxl to use any of the available public xmpp services. However, I choose to host my own jabber server for my blog.

JAXL_ADMIN_JID is the admin jid to which Jaxl should route all incoming messages, added specifically for wordpress related requirement. PHP connection manager can be extended to route different chat sessions to different admins.

jaxl_recv_message handler is used to embed smiley’s and youtube videos by parsing the incoming chat messages.

A few other hooks like jaxl_post_connect are used to notify JAXL_ADMIN_JID about the newly connected user.

Admin Screen
Below is a screen shot of how an admin desktop will look like while chatting with his site visitors:

Let me know if you are having any issues chatting using the chat bar at the bottom of the page. Code and installation might be buggy at times, and would appreciate any help from you on it.

Get real time system & server load notification on any IM using PHP and XMPP

Abhinav Singh — Mon, 11 Jan 2010 21:54:15 +0000

There are various system and server related information which server administrators always need to have as soon as possible, infact I must say in real time. There are several open and closed source softwares in the market which can generate almost real time notifications for you. Most famous one being Nagios. In this blog post I will discuss, how to generate real time system notifications using PHP and XMPP. Specifically, I will present sample script using Jaxl (Jabber XMPP Client Library) for generating real time system load notifications, which can be received using any Instant Messengers.

/proc/loadavg
We will be using system /proc/loadavg file to get real time system load information. If you are unaware about this file, here is in brief how this file is helpful to us:

sabhinav:~# cat /proc/loadavg
0.22 0.12 0.09 1/68 12621

where first three columns measure the CPU and IO utilization of last one, five and 10 minute periods. The fourth column shows the number of currently running processes and the total number of processes. The last column displays the last process ID used.

jaxl4serveradmins.class.php
We will be using Jaxl PHP client library for handling the XMPP part. jaxl4serveradmins.class.php is an extension to Jaxl, providing various server administration helper function. Below is the code for server administration extension:

  include_once("xmpp.class.php");

  define('JAXL_SERVER_ADMIN', 'mailsforabhinav@gmail.com');
  define('JAXL_SERVER_LOAD_POLL_INTERVAL', 10);

  class JAXL extends XMPP {

    function eventMessage($fromJid, $content, $offline = FALSE) {
    }

    function eventPresence($fromJid, $status, $photo) {
    }

    function eventNewEMail($total,$thread,$url,$participation,$messages,$date,$senders,$labels,$subject,$snippet) {
      // Not used here. See jaxl4gmail.class.php for it's use case
    }

    function setStatus() {
      // Set a custom status or use $this->status
      $this->sendStatus($this->status);
      print "Setting Status...\n";
      print "Done\n";

      $this->addJob(JAXL_SERVER_LOAD_POLL_INTERVAL, array($this, 'parseServerLoad'));
    }

    function parseServerLoad() {
      $loadavg = file_get_contents('/proc/loadavg');
      $this->sendMessage(JAXL_SERVER_ADMIN, $loadavg);
    }

  }

I have utilized addJob() method provided by Jaxl library, using which you can specify a callback to be called after every N seconds (in short a periodic cron). Here we add a periodic job to be runned every JAXL_SERVER_LOAD_POLL_INTERVAL seconds. parseServerLoad() method is called as the callback function.

$this->addJob(JAXL_SERVER_LOAD_POLL_INTERVAL, array($this, 'parseServerLoad'));

To keep the demo simple, I am simply sending the content of /proc/loadavg file as a message to server admins.

    function parseServerLoad() {
      $loadavg = file_get_contents('/proc/loadavg');
      $this->sendMessage(JAXL_SERVER_ADMIN, $loadavg);
    }

Running it for your servers:
Follow the following steps to get this started on your server (only Unix, no Windows):

Checkout from Jaxl trunk

sabhinav:~# sudo svn checkout http://jaxl.googlecode.com/svn/trunk/ jaxl-read-only

Enter checked out directory
```
sabhinav:~# cd jaxl-read-only
```

Enter your server admin IM contact details

sabhinav:~# sudo vim config.ini.php
define('JAXL_SERVER_ADMIN', 'webmaster@foobar.com');

Enable server administration extension

sabhinav:~# sudo vim index.php
include_once("jaxl4serveradmins.class.php"); // include_once("jaxl.class.php");

Wroom Wroom, start Jaxl

sabhinav:~# sudo php index.php
Starting TLS Encryption...
Attempting PLAIN Authentication...
Starting Session...
Requesting Feature List...
Requesting Roster List...
Setting Status...
Done

Tail the jaxl log file in case you are facing any difficulties in the setup.

sabhinav:~# tail -f log/logger.log

You should also consider adding /proc/ directory under open_basedir in php.ini file.

Is it working?
If all is well configured server admins will start getting notifications every 10 seconds which is default value for JAXL_SERVER_LOAD_POLL_INTERVAL.

Writing custom notifications
Above I demonstrate how we can use XMPP and PHP to generate real time system notification. However, you may want to modify parseServerLoad() method to send notifications only when the server load exceeds a certain value. You may also want to add other methods which can notify you of various System and Server level parameters in a similar fashion. Below are a few useful system administration commands:

sabhinav:~# free -m
sabhinav:~# vmstat 1 20

Is it really real time?
Since, parseServerLoad() method polls for /proc/loadavg file every 10 seconds, this is not exactly real time. However you can configure JAXL_SERVER_LOAD_POLL_INTERVAL to make it poll faster. You can also use libevent extension in PHP to make it real time in real sense.

Do let me know if you write any interesting functionality, I will be more than happy to include it as a part of current extension.

The testking offer complete learning of web development through the use of latest testking VCP-410 tutorials and other testking 640-802 php tools.

Get lyrics for any song using XMPP and PHP right into your IM – Add lyricsfly@gtalkbots.com

Abhinav Singh — Thu, 07 Jan 2010 17:03:39 +0000

XMPP is soon finding it’s way into real time applications other than just chat. I have combined JAXL (Jabber XMPP client library written in PHP) and the API from lyricsfly.com to build a real time chat bot which can assist you with lyrics for any song. You can start using it by simply adding lyricsfly@gtalkbots.com to your IM account (e.g. Gtalk, Jabber etc). In this blog post, I will explain in brief the working of lyricsfly bot and how you can integrate XMPP into your own application.

Try out lyricsfly@gtalkbots.com
Follow the following steps to get the bot working for you:

Login to your gtalk account using any of the IM available
Press Add Contact
Add lyricsfly@gtalkbots.com as your chat buddy
Send a chat message in following format “Song Title – Song Artist” e.g. “one – metallica”
You should see something like this:

Working of lyricsfly@gtalkbots.com with Jaxl
Here is in brief the working of lyricsfly bot using Jaxl client library:

When someone sends a message like “one – metallica” to the bot, eventMessage() method is called inside jaxl.class.php
eventMessage then extracts the song title and artist name from the message using PHP explode. Filter the title and artist names for allowed characters.
eventMessage also calls lyricsfly API and fetch the lyrics. Finally it sends the lyrics as message to requester.
eventMessage also uses memcached to cache the lyrics. It decreases both response time and load on lyricsfly servers
Bot also keeps a count of number of queries from a particular user. Since it is still under development, currently there is a limit on number of lyrics you can fetch in a single day.

Making your own custom bot

Checkout latest from the trunk

sabhinav$ svn checkout http://jaxl.googlecode.com/svn/trunk/ jaxl-read-only

Edit config file with your bot username, password and jabber servers
Run from command like
```
php index.php
```
To customize the bot modify eventMessage and eventPresence methods of Jaxl class inside jaxl.class.php

For a full fledged running bot example code, edit index.php and include jaxl4dzone.class.php instead of jaxl.class.php and re-run the bot.

Have fun and enjoy singing songs along with the lyrics.

How to use JAXL (Jabber XMPP Library in PHP) to import Gtalk contacts of any user

Abhinav Singh — Thu, 05 Nov 2009 14:31:19 +0000

JAXL is an open source Jabber XMPP Client library written in PHP. It provides a self titled class JAXL which implements XMPP protocol. It can be extended to write custom event handler for every message or presence received. Developers are using JAXL for developing real time applications. Checkout 5 exciting gaming bots you can make using JAXL.

However one thing which goes un-noticed is that JAXL can also be used to import Gtalk contacts of any user. This is infact one of the very first thing which JAXL class do, after successful authentication with the Gtalk servers i.e. import the authenticated user contact list. In this blog post I will demo a sample script to import any user contact list from google servers.

Importing Gtalk contacts using JAXL

Download and extract jaxl-1.0.4.rar

Edit config.ini.php and update credentials of the user whose contact list we are trying to import:

  $key = array("prod"=>array("user"=>"mailsforabhinav",
                             "pass"=>"xxxxxx",
                             "host"=>"talk.google.com",
                             "port"=>5222,
                             "domain"=>"gmail.com"
                            ),

Open jaxl.class.php and modify the code as below:

    function setStatus() {
      // Set a custom status or use $this->status
      $this->sendStatus($this->status);
      print "Setting Status...\n";
      print_r($this->rosterlist); // Print the contact list on the console
      print "Done\n";
      exit;
    }

Finally run from command line to retrieve gtalk contacts of the authenticated user.
```
php index.php
```

One can easily modify the above code to save user contacts in a database.
Also one can echo json_encode($this->rosterlist) in response to an Ajax call from the browser.

Enjoy and leave your comments.

Programatically control your google mails using JAXL v 1.0.4

Abhinav Singh — Fri, 06 Feb 2009 18:10:30 +0000

Google has released an API for almost all of their products including maps, feedburner and gadgets. However one of the API’s which every developer would have loved to make use of is “Google Mail API” which is still missing (available for premium google apps user only). Here in this post I would demonstrate how one can programatically control his/her google mails using JAXL without being a premium user of google mail account.

For those who have landed on this post straight and have little knowledge about what JAXL is “JAXL stands for Jabber XMPP Library and for fun you may call it Just Another XMPP Library. It is written in PHP and can be downloaded from http://code.google.com/p/jaxl“. To know more about JAXL, read the introductory post here. If you want to dig deep and know how JAXL works, read the gtalk case study here. Finally, after reading this post you may also want to check how you can fetch any social networking feed right into your gtalk messenger using JAXL.

Version 1.0.4 of JAXL included support for “Gmail Notification Extension of XMPP“. If you are a daily Gtalk user like me, then you have surely seen this extension in action. Just recall Gtalk notifying you of a new mail in your inbox, through a pop-up in the bottom right corner. Also those who see this in action everyday will agree with me that this notification comes even before the mail has actually appeared in you inbox. Simply because of the PUSH technology used by XMPP protocol.

So why would you in first place be interested in accessing your google mails programatically. A quick thought on this brings me to the following real life scenarios:

Suppose your are out of vacation and you want to set a custom auto-reply message for your family and friends, while you want to set a general out-of-office message for your colleagues. The limitation in gmail is that you can’t really do this. Further in this post, I will show you how can you achieve this using JAXL.
Suppose you are a google app user and your company has organized an online programming contest. Further you want to mail each question to the contestants only if they has answered the previous question. JAXL provide you a way to access key information about your incoming mails like: sender email id, subject, number of threads in the mail, time at which mail was sent, mail url and mail snippet. Which is enough for you to code a bot which can check for incoming mail and then send in next question to the contestant who sent this mail

Sending Custom Auto-Reply Mails using JAXL
Along with extendable functions like eventMessage() and eventPresence(), JAXL’s latest version now also provide another extendable function called eventNewEMail(). So everytime you receive a new mail(s) in your google account, the control is passed to this function along with all informations about the incoming mails.

Various data passed to this function are:

$total: Tells you about total number of unread mails.
$thread: The thread id of all the unread threads. Note: In Gmail you have threads in your inbox which can contain more than a single mail.
$url: The mail.google.com url for the new mail
$participation: This can be 0, 1 or 2. 0 indicates that you have not participated, 1 indicates that you are one of the many recipients and 2 indicates that you are the sole recipient for messages in this thread
$message: The number of messages in the thread. For instance you can have more than one unread mail in a thread.
$date: A timestamp of the most recent unread message, in milliseconds since the UNIX epoch
$senders: Email Id of all the senders in the current thread
$labels: Label if any to which this mail thread belongs to
$subject: The subject of the mail threads
$snippet: The mail snippet of the incoming mail

So thats a lot of information really, with which we can automate things to a certain extent. Lets see how I use it to send custom auto-reply mails when I am out on vacation. Here is the extendable jaxl class for gmail:

jaxl4gmail.class.php (Download)

  /* Include PHP Mailer Class */
  include_once("class.phpmailer.php");

  /* Include XMPP Class */
  include_once("xmpp.class.php");

  class JAXL extends XMPP {

    /* Define custom mail groups */
    var $family = array("mom@gmail.com","dad@gmail.com");
    var $colleague = array("boss@company.com","manager@company.com");

    /* Define custom mail subject and message */
    var $familySubject = "Hi, Will get back to you";
    var $familyMessage = "Hey, I am currently out on vacation at my grannies house in Delhi. I will return back home by next monday.
Reach out to me at +91-987654321.

With Love,
Abhinav Singh";

    /* Define custom mail subject and message */
    var $colleagueSubject = "[Auto-Reply] Out of Office";
    var $colleagueMessage = "Hi, I am on vacation in my village with very limited access to internet and phone. I will return back home by next monday.

Regards,
Abhinav Singh";

    function eventMessage($fromJid, $content, $offline = FALSE) {

    }

    function eventPresence($fromJid, $status, $photo) {

    }

    function eventNewEMail($total,$thread,$url,$participation,$messages,$date,$senders,$labels,$subject,$snippet) {
      // We only want to send auto-reply message to latest sender
      $sender = $senders[0];

      // Check if the user lie in any category, and send appropriate mail
      if(in_array($sender["address"],$this->family)) {
        $mail = new PHPMailer();
        $mail->From = "youremailid@gmail.com";
        $mail->FromName = "Your Name";
        $mail->Subject = $this->familySubject;
        $mail->MsgHTML($this->familyMessage."

Powered by Jaxl http://code.google.com/p/jaxl");
        $mail->IsHTML(true);
        $mail->AddAddress($sender["address"],$sender["name"]);

        if(!$mail->Send()) $this->logger->logger("Error occured while sending mail to ".$sender["address"]);
        else $this->logger->logger("Mail sent successfully to ".$sender["address"]);
      }
      else if(in_array($sender["address"],$this->colleague)) {
        $mail = new PHPMailer();
        $mail->From = "youremailid@gmail.com";
        $mail->FromName = "Your Name";
        $mail->Subject = $this->colleagueSubject;
        $mail->MsgHTML($this->colleagueMessage."

Powered by Jaxl http://code.google.com/p/jaxl");
        $mail->IsHTML(true);
        $mail->AddAddress($sender["address"],$sender["name"]);

        if(!$mail->Send()) $this->logger->logger("Error occured while sending mail to ".$sender["address"]);
        else $this->logger->logger("Mail sent successfully to ".$sender["address"]);
      }
      else {
        // Do nothing, will handle later on
        $this->logger->logger("No handler for this email id...");
      }
    }

    function setStatus() {
      print "Setting Status...\n";
      $this->sendStatus("Available");
      print "Requesting new mails...\n";
      $this->getNewEMail();
      print "Done\n";
    }

  }

The only variables you would like to change in above class are:

$family : An array of email id of your family member
$colleague : An array of email id of your colleagues
$familySubject : Subject with which you want to send mails to your family members
$familyMessage : Mail message which you want to send to you family
$colleagueSubject : Subject with which you want to send mails to your colleagues
$colleagueMessage : Mail message which you want to send to you colleagues

For further customization, you may want to add more groups and their respective subjects and messages.

Further you may want to create your own custom bots using JAXL for one of the other use case described above. Join official JAXL Google Group for future updates and enhancements.

Do let me know if you build any custom bot using JAXL, I will be more than happy to list your bot on official JAXL google code page.

Enjoy!