I am programming an IRC gateway to another protocol, and I want my IRC server (the gateway) to notify the IRC client when other users are connected or disconnected.
This feature is supported by my IRC client (Quassel) : it shows me when a user set himself as /away, but I can't figure out what command my IRC server must send to set/unset user presence.
You ideally implement the IRCv3 spec away-notify: http://ircv3.net/specs/extensions/away-notify-3.1.html
Otherwise your client has to spam WHO polls often to get the latest status of users.
Related
I'm wondering how (official) GTalk clients manage to show all messages received - even if it was originally consumed by another client. For example: I'm logged into GTalk on gmail.com on my laptop and, at the same time, via the official GTalk app on my Android device. A friend sends me a message, which is displayed on both the gmail.com client and the Android client. (I think it's originally only forwarded to one of either clients, but the second client fetches the message later on)
I recently found out that there's a very similar XMPP feature, called Carbons. However, after a quick service discovery request Google's servers didn't advertise this feature. XEP-0313 and XEP-0136 look good too, but the servers don't advertise them either.
Possibly related question: Deliver Google Talk message to all logged in clients using XMPPPY
When you initiate a new chat then you should send the first message to the users bare Jid. This is what most clients are doing. When the GTalk server retrieves a chat message to a bare Jid it routes the message to all available resources. For all following messages in this conversation the clients normally pick up the Resource and send them to full Jids. The messages should not be replicated then.
Many other servers don't route message to bare Jids to all resources, but to the most available resource which is the client with the highest priority.
Here is a quote form the RFC:
If there is more than one resource with a non-negative presence priority then the
server MUST either
(a) deliver the message to the "most available" resource or
resources (according to the server's implementation-specific algorithm, e.g., treating
the resource or resources with the highest presence priority as "most available") or
(b) deliver the message to all of the non-negative resources.
XEP-0280 defines this. As I understand, it defines the mechanism to notify all the resources from same user when one of them sends a message to anyone. I mean, Alice/pda sends a message to Bob, so Alice/mobile and Alice/PC will receive a copy of the message sent be Alice/pda.
Hope it helps. I am currently looking for a server that implements this, and also for a client library. If not, I will implement it by myself in both jabberd2 and gloox xmpp library.
Cheers,
Let's suppose I have created an IMAP client and I want to create a filter that, say, deletes messages that have certain characteristics.
I can make this a startup task that happens whenever the client is opened, but the problen is that a user might view the inbox in a different client and the filter won't get rid of the unwanted messages before the inbox is viewed.
Is there some way to tell the server to call my service every time it receives a message so the unwanted messages can go away once the server receives them instead of once a client is opened? Is this even possible with IMAP? If not, is there a different well supported e-mail technology that allows this sort of interaction?
You can do server-side email filtering with the Sieve Email Filtering Language and the ManageSieve Protocol. There is good support in open-source software. However, I am only aware of a few major email providers, that support it. If it is supported, it is usually accessible on the IMAP host and with the IMAP account credentials, i.e. you can test it by connecting to TCP port 2000 and 4190.
See the following three links for more information:
http://en.wikipedia.org/wiki/Sieve_%28mail_filtering_language%29
https://www.rfc-editor.org/rfc/rfc5228 (Sieve: An Email Filtering Language)
https://www.rfc-editor.org/rfc/rfc5804 (ManageSieve Protocol)
Sieve also supports a few notifications types. If the filtering language is not powerful enough to for your purposes, you can send notifications for all incoming emails, wake up the IMAP client, and let the client to the filtering.
XMPP allows users to connect to the server from multiple clients simultaneously, using the same account. I built an application that does this but if the desktop client is enabled, I do not want the users to be able to connect using a mobile client. This is for a game and being connected to both causes problems.
So what I'm wondering is:
Is it possible to detect if there are other clients connected using the same account. If I can check for other clients, I can auto logout the user.
#Flow was on the right track. If all of your client instances use the same resource, in most servers, the later-connecting client will replace the older session. The older session will get a conflict stream error, and be disconnected. You MUST be careful not to auto-reconnect with the older client, or you will have written the "dueling resources" bug.
If you had control over your server, you have a chance at configuring it to allow a maximum of one resource for a given user, in which case the newer connection will fail with a conflict error, but you'll have worse user interface problems if you head down that path; there will be no way to get the second client logged in, even if you wanted to.
Finally, all resources for a given user are subscribed to that user's presence. As long as your client sends presence in:
<presence/>
you will receive presence from each of your other devices:
<presence to='user#example.com/resource1' from='user#example.com/resource2'/>
<presence to='user#example.com/resource1' from='user#example.com/resource3'/>
<presence to='user#example.com/resource1' from='user#example.com/resource4'/>
You could use this to decide which client is current, perhaps by adding an extension to the presence like XEP-0115.
Give the desktop and mobile client a fixed but different resource string. If the mobile client logs in, it can detect the presence of the desktop client by looking up the presence/availability of the resource of the desktop client and vice versa.
Then you only need to implement an custom XMPP ad-hoc command (XEP-0050) that tells the conflicting resource to log out.
It would be the servers responsibility: to reject a login from a client that is not accepted. I don't know if servers are able to blacklist xmpp clients but, in case you use openfire, you should be able to write an extension.
I am basically writing a XMPP client to automatically reply to "specific" chat messages.
My setup is like this:
I have pidgin running on my machine configured to run with an account x#xyz.com.
I have my own jabber client configured to run with the same account x#xyz.com.
There could be other XMPP clients .
Here is my requirement:
I am trying to automate certain kind of messages that I receive on gtalk. So whenever I receive a specific message eg: "How are you" , my own XMPP client should reply automatically with say "fine". How are you". All messages sent (before and after my client replies) to x#xyz.com but should be received by all clients (my own client does not have a UI and can only respond to specific messages.).
Now I have already coded my client to reply automatically. This works fine. But the problem I am facing is that as soon as I reply (I use the smack library), all subsequent messages that are sent to x#xyz.com are received only by my XMPP client. This is obviously a problem as my own client is quite dump and does not have a UI, so I don't get to see the rest of the messages sent to me, thereby making me "lose" messages.
I have observed the same behavior with other XMPP clients as well. Now the question is, is this is a requirement of XMPP (I am sorry but I haven't read XMPP protocol too well). Is it possible to code an XMPP client to send a reply to a user and still be able to receive all subsequent messages in all clients currently listening for messages? Making my client a full fledged XMPP client is a solution, but I don't want to go that route.
I hope my question is clear.
You may have to set a negative presence priority for your bot..
First thing to know is that in XMPP protocol every client is supposed to have a full JID. This is a bare JID - in your case x#xyz.com with a resource in the end e.g. x#xyz.com/pidgin or x#xyz.com/home (where /pidgin and /home are the resource). This is a part of how routing messages to different clients is supposed to be achieved.
Then there are the presence stanzas. When going online a client usually sends a presence stanza to the server. This informs about e.g. if the client is available for chat or away for lunch. Along with this information can be sent a priority. When there are more than one clients connected the one with the highest priority will receive the messages sent to the bare JID (e.g. ClientA(prio=50) and ClientB(prio=60) -> ClientB receives the messages sent to x#xyz.com). But there are also negative priorities. A priority less than 0 states that this client should never be sent any messages. Such a stanza might look like this
<presence from="x#xyz.com/bot">
<priority>-1</priority>
</presence>
This may fit your case. Please keep in mind it also depends on the XMPP server where your account is located, which may or may have not fully implemented this part of the protocol.
So to summarize: I recommend you to look through the Smack API how to set a presence and set the priority to <0 for your bot client right after it connected.
I'm working on a design for a xmpp chat solution which involves some servers and where at least one server is connected with serious bandwidth limitations.
Assuming, we have two servers A and B, some users 0..n connected to Server A and some conferences 0..m provided by Server B.
Now assume, some users enter a conference room and a message is sent to that room. Will
Server B send this message once to
Server A and Server A distributes it
to the users or will
Server B send this message to each individual user of Server A?
According to the protocol spec, XEP 045, multi-user chat messages are reflected independently to each participant. I can't tell on a brief read if it is legal to send them server-to-server without reflecting. However, it might be worth asking this question on an xmpp.org mailing list, where the experts tend to hang out.