jdev - 2020-04-14

Hello, is there a way to check whether a nickname is available *before* joining a MUC? XEP-0045 has a section on discovering whether you've already registerd a nick for yourself in the MUC, but I don't see anything about checking whether a particular nick is available.

that would mean having access to the participant list before joining?

in a way

jcbrand: what's the issue with trying to join with a nickname you want to use?

Ge0rG: there is no issue, I want users of a particular service that is built on XMPP to be able to check availability of a nickname before actually joining with that nickname.

pep. I don't think you need the participant list. Could be as simple as sending an IQ to a MUC and asking whether a particular nick is taken or not

jcbrand: that's a kind of access to the occupant list. You could enumerate nicknames that way ;)

this ^

Which you maybe don't want in some cases, but in others you don't mind whether someone can enumerate the nicknames

it's a feature 🙂

:/

Also, if the service tells you that a nick is not available, it might also be due to other reasons, not neccessarily that it's taken ✏

Also, if the service tells you that a nick is not available, it might also be due to other reasons, not necessarily that it's taken ✏

in a world where presence is moot, like the xep you just published, can you not just attempt a join?

(it's your xep right?)

You still get all the presence stanzas initially when you join for the firs ttime ✏

You still get all the presence stanzas initially when you join for the first time ✏

sure, but you know right away if the nick is available or not

you get an error otherwise

also you have a "lock" on the nickname at that point

which is good, because someone could steal your nickname between you checking via the IQ and you actually joining

right, also that

Very unlikely and not something worth worrying about IMO

I think the value of being able to check outweighs that concern in my case

I'm saying you already have the tools to check

Not before you join the room

jcbrand, could you do nickname registration?

joining the room is just a technical detail

you don't have to show it in the UI right away

pep. it's a detail that complicates the code and causes unnecessary traffic

pep., it’s not, it discloses the join attempt to everyone and also causes traffic ✏

jonas’: if the goal is to join anyway..

you also have to leave the room if the user decides to pick a different nickname after the check and deal with all the stanzas you get after joining

jonas’ AFAIK you can only register a nick *after* joining the MUC

pep., in my mind, there’s a "pick your username" form where a green tickmark appears when you move focus away from the nickname field. The user could still change the nickname later (before joining) or abort the process.

Yes, I didn't say that the goal is to join anyway

You might decide not to join because a particular nick is taken already

that's an issue only if the nick isn't already taken

?

others wouldn't know you tried to join if the nick is already taken as you get an error

jonas’ what you describe is roughly what I'm after. I think making it possible to allow nick registration without joining a MUC is the solution

jcbrand, you still have to un-register the nickname if the user aborts the flow in some way

uh yeah of course...

maybe by expiring all nickname registrations which never joined after 5 minutes or something like that

😛

"of course" :p

Seems a bit kludgy

"oops the user quit the client"

(and also explicitly un-registering when the user changes their choice)

jcbrand, not really. having a control loop which does cleanup of (expected and unexpected) error cases is a good thing™

I think something like nick registration, but that simply indicates availability is preferable. Could be a new XEP, and if people hate it I might then just do it for this one use-case