Support for Message Moderation

[Ppjet6]

Is your feature request related to a problem? Please describe.
When undesirable messages are sent to the channel, it can help being able to retract them.

Describe the solution you'd like
https://xmpp.org/extensions/xep-0425.html

Message moderation allows a moderator a room to retract messages so that they are not shown anymore on supporting clients. It also tells servers to tombstone them so they don't reappear when fetching history next time.

As a first step, implementing support in reading (retracting a message in local history when receiving the stanza, or showing the tombstone from the archive) would be enough for joinjabber's use case.

I don't think xmpp-web has a way to attach messages (reactions, replies, etc.) to other messages at the moment so I understand if the sending part is more complex.

Describe alternatives you've considered
I don't think there is many alternatives available. Spam messages clogging the chat for example are a pain to workaround, the only available way currently is to let it slide out of screen (after having kicked out the spammer).

[nioc]

Can you link me the XEP / XML message which notify client to remove some spam messages?
We can handle it to find and remove spam in store.

[Ppjet6]

There's a few things that could be improved in this spec, but it works ok..

A Moderated message is a retracted message (XEP-0424) sent by a moderator through MUC.

It requires Iqs to send the command to retract as a moderator, and then messages are broadcasted to participants, so messages with this payload shouldn't come directly from participants. Whenever you see such a payload, make sure the MUC actually advertises urn:xmpp:message-moderate:0 first.

A broadcast message looks like this: https://xmpp.org/extensions/xep-0425.html#usecase-success

And then from MAM you can also get such payloads as specified here: https://xmpp.org/extensions/xep-0425.html#tombstones.
You'll need to handle XEP-0424 as above of course, and also https://xmpp.org/extensions/xep-0421.html occupant-id.

Don't hesitate to join xmpp:jdev@muc.xmpp.org?join, I and other devs should be there to answer if you have any questions.

[nioc]

Hello, I do not know how to retract a message with my usual XMPP clients (Gajim 1.3.3 on laptop, Conversation 2.12 on Android).

It there some Prosody plugin required for client show an option?
By the way, I am thinking to put some "reproducing environments" in the repo which includes docker-compose.yml and server config files. I will probably ask for your assistance to check/complete the pull request.

Without testing, I can not implement it... 😞

[nioc]

As I explained earlier, it would help me if you could provide the associated Prosody setup in #89.

[github-actions]

This issue will be closed within two weeks if the requested reproduction data is not provided. Please refer to this guide.

[Ppjet6]

prosody-moderation.tar.gz

I hope I did it as you expect. I basically pulled the mod_muc_moderation module and added it to the MUC's modules_enabled.

[nioc]

Thanks a lot for this!

I will try to reproduce today. Does Gajim has the moderation function?

[Ppjet6]

It looks like Gajim, Conversejs, Pade and poezio (sending only) have support for this feature.

[nioc]

I am a noob in thins kind of stuff and I do not find any option in Gajim to retract a message.

Here are the XMPP server functionalities see through Gajim (1.3.3):

I have try the room history, then history manager and delete message... but it seems to delete only on Gajim local database (I did not see anything in the websocket, neither in Prosody logs) 😞

Can you give me the procedure to retract a message in a room?

[nioc]

Okay… I need to update Gajim to 1.4

Both server and client have to support this standard, and you have to be Moderator/Admin/Owner in order to be able to retract messages. Gajim 1.4 will support message moderation in both ways: by offering moderation actions for messages, and by displaying a disclaimer for message which have been moderated.

https://gajim.org/post/2021-11-29-development-news-november/

[Ppjet6]

If you're using Debian, there's 1.5.1 available in bullseye-backports, otherwise 1.7.1 is available on the upstream repository

[nioc]

Nop Ubuntu (to get newer packages 😆).
But I move to Gajim nightly, it is fine.

[nioc]

Here we are, does this UX sound good to you?

I was wondering if I should hide the message, but the user may wonder why his message disappeared, so reducing opacity should be better, your opinion?

[nioc]

Also another question @Ppjet6, I understand that this only applies to MUC, can you confirm? I would like to use Jid resource instead of the full Jid.

[Ppjet6]

I think leaving a trail that there was a message here is good. And yes I was going to say, I would just use the nickname (resource) and not the fulljid.

The spec uses "retract" as the verb, I'm not saying it's not possible to use anything else but maybe it makes sense to keep the same terminology here? I don't know what other clients do.

[nioc]

For the wording, I think Retracted is not clear for non RFC-XEP-expert users.
If Removed is not ok, I suggest Moderated.

[Ppjet6]

Ok, both are fine with me. moderated may be more obvious?

[nioc]

Yep. New proposal:

`Moderated by ${nick} (${reason})`

With a red icon at bottom.

[Ppjet6]

The spec isn't explicit about the reason, but I would say it's optional. I would find it weird not to. I've asked around.

[nioc]

I pushed in a branch, so you can review and tell me in the pull request if something is wrong.
I will add a few comments to highlight the key points.

[Ppjet6]

https://mail.jabber.org/pipermail/standards/2023-February/039164.html

Just so you know, this is a thing, and it's possible things change. I'll keep you updated!