I am trying out a project on OpenShift using Aerogear UPS. I am able to push messages to the clients, but is there a way to get messages from the client?
Aerogear seems to be the only packaged XMPP solution on OpenShift, and it appears to be one way messaging platform. Please tell me it ain't so.
It ain't so. *
Well it kind of is so but not for long! In UPS 1.1.0 we are planning on introducing support for metrics support. Right now it is just a glorified read receipt with a phenomenally sexy dashboard. In UPS 1.2.0 we are moving the metrics from HTTP to XMPP messaging (for Android). Please comment on our JIRAs (https://issues.jboss.org/browse/AGDROID-433) or bug us on the aerogear mailing lists (https://aerogear.org/community/#contact).
Google GTalk clients (web, android, windows) have great ability to suck conversation history from server, even though conversations were done an another jabber client.
What jabber (XMPP) functionality (XEP) is used for that or is it some custom thing?
Why no other XMPP client (non Google) has this ability?
P.S. It is programming question, because I am asking about specific XMPP functionality.
It is possible that this is done using message archiving. See XEP-0136: http://xmpp.org/extensions/xep-0136.html
(And with regard to the other answer, this is supported by ejabberd: http://www.ejabberd.im/mod_archive)
Its a property of XMPP server not XMPP/Jabber client. All conversation happens through XMPP Server. So If server wants it can store all the history. As far as I know there is no open source XMPP server which can store history.
Google has it all.
I am not sure, but I think there is no specific XEP for storing history on server.
Server side XEP-0136 (message archiving) can be done with ejabberd + mod_archive (mod_archive_odbc variant with sql backend, for better perfomance) or with openfire server with open archive plugin.
Client side, for XEP-0136 I use vacuum im, http://code.google.com/p/vacuum-im/ , it's open-source and cross platform.
Does JavaMail support notification of new emails through server-push?
If yes, where is the documentation for that?
If no, is there a library that can do it?
You should be using IMAPFolder's idle function to issue the idle command to the server. That will then listen for events, such as a new mail or deleted mail. (See the IMAP spec to see what the messages look like). And you should be using a MessageCountListener to execute code when a number of emails in the mailbox change.
IMAP's idle function is exactly meant to imitate "push" functionality.
http://java.sun.com/products/javamail/javadocs/javax/mail/event/MessageCountListener.html
http://java.sun.com/products/javamail/javadocs/com/sun/mail/imap/IMAPFolder.html
Sorry I didn't post any code that shows how this is used. I didn't want to waste my time since there are many readily available examples on the internet if you search for this stuff.
But be forewarned, this method won't work for more than one IMAP account since the idle command blocks. Unless you want them all on different threads (bad idea).
A Store event listens for notifications issued by your backend store:
http://java.sun.com/products/javamail/javadocs/javax/mail/event/StoreEvent.html
But in my experience the java mail docs are so thin in places, that the best way of finding out what is going on, is to debug through the process yourself.
This is a great allround resource as well; the JavaMail FAQ :
http://www.oracle.com/technetwork/java/faq-135477.html
I'm currently looking into XMPP and I would like to know if there is a way to create dynamic XMPP rosters. I want the contact list of any user be automatically generated by the server / component / plugin.
Can components access and modify rosters?
I know that some servers (like OpenFire) use an external database to store these information but if I modify the database, I don't think the users will be notified in realtime.
Are some people already doing that or do you have an idea how to create it?
Thank you for your time.
In most XMPP servers this is called "shared roster groups".
I can't comment on Openfire in particular because I haven't used it for a long time, but I don't think I know of a server currently in which external roster changes are instantly transmitted to clients. Usually the client will simply pick up the new roster when it next logs in.
It would be possible to push the updates instantly to clients using what XMPP calls "roster pushes". This would require quite some work on the server though to identify what the changes are between what each client knows the roster to be, and what the new roster is, and then transmit just the changes.
If you really need this then a server plugin would probably be the way to go, or pester your server developers for the feature (I know that as a Prosody developer I've already been pestered, and this is something I'm planning to work on).
As for whether components can access users' rosters - this is dependent upon the server implementation and configuration.
Beside the obvious person to person instant message chat, What else have you used a Jabber server's functionality to enable?
Edit: links to working code to really show it off are particularly useful - and will be more likely to be voted up.
There are unlimited uses for XMPP/Jabber.
Take any message/data you want to send somewhere else and you can use jabber. Run a centralised logging service for distributed services? You can jabber the massage.
You want to check if your services/programs are running? XMPP presence will tell you. If you add custom status messages you can see exactly what is going on.
This is why Cisco has got into the game. Picture a server farm where each blade has a built in mini jabber client. On boot up it will register it's presence to the central server as awaiting work. The central server fires off some work in it's direction and it then changes it's status to "Busy". Another blade finished it's work and changes it's status back to "Available"... rinse and repeat.
When you combine the actual jabber messages with it's Out Of Band abilities, these servers can post where the results of the job can be found.
Anything you can think of needing to pass a message can be done with XMPP to some degree. Be this person to person, program to program, or any combination.
You could use a Jabber server to handle/broker messages between a client application and another server application.
It can actually be pretty effective.
Not me but Martin Woodward used jabber to control a "build bunny" that displays the current status of the build server.
http://www.woodwardweb.com/gadgets/000434.html
XMPP is good for sending messages back and forth between computers that don't need to be broken into chunks. They also can't be terribly big. If you use the right library, it can be pretty easy to set up.
Sending messages to a web page. Proof-of-concept: esagila.com
I plan to use it to receive notifications from my system, such as:
Process did not finish
Report was not generated on time
User needs help
I already receive many of these messages as email. But receiving an IM could be much more effective.
You might want to look at Vertebra which is...
a framework for orchestrating complex processes in a Cloud. It is designed with an emphasis on security, fault tolerance, and portability.
From the knowledge base:
Why was XMPP chosen for Vertebra?
XMPP based instant messaging can be a good alternative to search engines for information that is small, complete in itself and required frequently and repeatedly. For example, your daily horoscope - you require it daily and it is not large.
To see an example of this add astro#askme.im to your list of contacts in your jabber client (Gmail Chat/Gtalk/or any other Jabber client) and then initiate chat with this contact by sending the word "help".
Also see www.askme.im for a whole list of chat based solutions.
I've used Jabber in the past to get email notifications. Nowadays I use it for low-priority nagios notifications, it is very useful and way cheaper than SMS:
We use xmpp as both a 'bus' and a real-time API at http://superfeedr.com
Iowa State University Department of Agronomy has created this with Jabber: http://mesonet.agron.iastate.edu/iembot/
If you're a weather freak like I am, this is VERY cool stuff!
Apple implements mobileme's push service using Jabber/XMPP's subscription services to send push notifications. That is the most widespread use of Jabber for non-IM purposes I know of. This article has more details.
My friends have also built a Jabber python bot, which is kinda cute but not all that useful :-)
Edit
The most recent Next Big Thing, Google Wave, uses Jabber under the hood. Further illustrates the power of the protcol.
We have used XMPP and BOSH to enable users to communicate with a webbrowser directly and in realtime from their phone.
For example Code you can view our open source API
The vooices site also has live examples where you can control a map and play a game using your phone via your web browser: http://www.vooices.us/
I've always thought XMPP would be a good way to deliver SNMP data. OIDs are really painful, much of the system is insecure, and the SNMP traps never work quite like you want them to. With an XMPP server in the middle and a smart component to make some choices, you can use it to send out jabber or other notifications, kick off restart jobs, update web pages, or whatever else you need.
The XML data is pretty small in this case, and you can have the one XMPP server both talk to humans in message stanzas, or computers with the same protocol.