I'm experimenting with socket.io and trying to build a multi-room chat app. The guide I'm following is out of date using pre 1.0.0 socket.io.
I'm trying to find a list of connected clients in a given room. Googling around shows that I have to use the adapter. However, I cannot find the documentation for it anywhere. I searched for it in the git-hub doc but search didn't return any information on adapter. https://github.com/socketio/socket.io-client/blob/master/docs/API.md
Can someone point me in the right direction and where I can read more about adapter and associated methods on it? Also if you can provide the most up to date documentation for socket.io I'd greatly appreciate it. Thank you.
You can get a map of all rooms in the top level namespace like this:
io.nsps['/'].adapter.rooms
You can list the sockets in one of those rooms like this:
function getSocketsInRoom(room, namespace = '/') {
let room = io.nsps[namespace].adapter.rooms[room];
return room.sockets;
}
As best I can tell, this kind of stuff is simply not documented. I've only discovered things like this by examining how things are stored in the debugger. That may or may not mean it's subject to change in the future - I really have no idea.
sockets:
{ '2v8OmIS4qTGX61-YAAAC': true, '3YnScxOgpmAGhZWsAAAG': true },
length: 2 }
it gives u this output. So it basically gives you the clientId and whether it is connected or not and total number of clients connected to a specific room. When the code below is executed (in server side written in node.js) gives u the above output.There is currently two clients connected to the same room named "hello".
var clientsInRoom = io.sockets.adapter.rooms[room];
but when u write this code below and console log it
var clientsInRoom = io.sockets.adapter.rooms
when single client is connected it will console log this
{ '9mVAHSDwcwnqsF4aAAAA':
Room { sockets: { '9mVAHSDwcwnqsF4aAAAA': true }, length: 1 } }
this crazy '9mVAHSDwcwnqsF4aAAAA' literals is client id which is unique for each client
Related
I'm trying to develop an API for multiplayer online using socket programming in node js
I have some basic questions:
1. How to know which connection is related to a user?
2. How to create a socket object related to another person?
3. When it's opponent turn, how to make an event?
4. There is a limited time for move, how to handle the time to create an event and change turn?
As it is obvious I don't know how to handle users and for example list online users
If you can suggest some articles or answering these questions would be greate
Thanks
Keep some sort of data structure in memory where you are saving your sockets to. You may want to wrap the node.js socket in your own object which contains an id property. Then you can save these objects into a data structure saved in memory.
class User {
constructor(socket) {
this.socket = socket;
this.id = //some random id or even counter?
}
}
Then save this object in memory when you get a new socket.
const sockets = {}
server = net.createServer((socket) => {
const user = new User(socket);
sockets[user.id] = user
})
I am unsure what you mean by that, but maybe the above point helps out
This depends on when you define a new turn starts. Does the new turn start by something that is triggered by another user? If so use your solution to point 2 to relay that message to the related user and write something back to that socket.
Use a timeout. Maybe give your User class an additional property timeout whenver you want to start a new timeout do timeout = setTimeout(timeouthandler,howlong) If the timeouthandler is triggered the user is out of time, so write to the socket. Don't forget to cancel your timeouts if you need to.
Also, as a side note, if you are doing this with pure node.js tcp sockets you need to come up with some ad-hoc protocol. Here is why:
socket.on("data", (data) => {
//this could be triggered multiple times for a single socket.write() due to the streaming nature of tcp
})
You could do something like
class User {
constructor(socket) {
this.socket = socket;
this.id = //some random id or even counter?
socket.on("data", (data) => {
//on each message you get, find out the type of message
//which could be anything you define. Is it a login?
// End of turn?
// logout?
})
}
}
EDIT: This is not something that scales well. This is just to give you an idea on what can be done. Imagine for some reason you decide to have one node.js server instance running for hundreds of users. All those users socket instances would be stored in the servers memory
Hi all :)
I need to get all clients in a room.
I have found the following code and it's works:
var clients = io.sockets.adapter.rooms['queue'].sockets;
// Output is client ID and true/false value
The issue is that I need the socket ID from each client.
clients.id or clients.socket.id ..
Does not work. Output is undifined.
Has anyone a solution for my issue ?
Second question:
Alternativ was my idea that I put all user ID's if the client is joining in a javascript array or list etc. But if I have above 500 or 1000 clients in a list .. I think that is a little bit unfavorable ?
Thanks
David
I'm trying to figure out basic websocket communication using node.js, the "ws"-package (which seems to be a very popular websocket package from npmjs.com) and the bitfinex.com (a cryptocurrency exchange) websocket API.
I want to read the public Ticker for a certain currency-pair, the docs are here: https://docs.bitfinex.com/v2/reference#ws-public-ticker
My result so far is working but is still much different from what I am supposed to get according to the docs.
I am working with this code snippet taken from the documentation linked above:
const ws = require('ws')
const w = new ws('wss://api.bitfinex.com/ws/2')
w.on('message', (msg) => {
console.log(msg)
})
let msg = JSON.stringify({
event: 'subscribe',
channel: 'ticker',
symbol: 'tBTCUSD'
})
w.on('open', () => {
w.send(msg)
})
Which works so far by outputting to the console the message from the subscribed channel:
[1,[14873,23.49464465,14874,61.09031263,1087,0.0789,14872,56895.20497085,15500,13891]]
But now, and here is the issue, in the docs the response looks different. How would I determine which number is what? I should be able to get all kinds of more information from the response, no?
The given example response looks like this:
// response - trading
{
event: "subscribed",
channel: "ticker",
chanId: CHANNEL_ID,
pair: "BTCUSD"
}
How does this relate to that array of numbers I get? How would I for example read the "pair:" field ("BTCUSD") or any of the other listed fields, like (BID, BID_PERIOD, VOLUME, HIGH, LOW etc.)? Am I missing something obvious?
I know this is a lot to ask at once but maybe someone knows one or two good examples or hints to enlighten me. Thanks in advance!
Kind regards,
s
The overall websocket scheme for this API is described in https://bitfinex.readme.io/v2/docs/ws-general If you haven't already read that page, now would be a good time to do it.
For your example program you should have seen info and subscribed events as the first two messages from the websocket. info should have been sent as soon as the websocket connection was established, and subscribed should have been sent in response to your subscribe request.
After that, you should see a ticker snapshot message followed by periodic ticker update messages for the channel that you subscribed to. These are the JSON arrays that you're seeing. The format of these messages for a public ticker channel is is described at https://bitfinex.readme.io/v2/reference#ws-public-ticker -- click the Snapshot and Update headings in the dark green 'details' bar to see the definitions. In this case snapshots and updates use the same format:
[ CHANNEL_ID,
[ FRR, BID, BID_PERIOD, BID_SIZE, ASK, ASK_PERIOD, ASK_SIZE,
DAILY_CHANGE, DAILY_CHANGE_PERC, LAST_PRICE, VOLUME, HIGH, LOW
]
]
with meanings as described in the 'Stream Fields' table at the above URL.
You can parse these messages as JSON strings and access the field values just as you would for any array.
It's a little strange that the API sends these as arrays rather than as objects with named attributes. I imagine they're looking to keep these messages compact because they make up the bulk of the traffic.
TL;DR below.
I am currently developing a React/Redux SPA that is driven by real-time data. I've decided to use ws, instead of socket.io since socket.io feels a bit high level for what I'm doing, I'd rather manage sockets myself.
In saying that, I'm struggling to find a way to manage the separation of updates/messages per view/route. Since I'm using client-side routing it's per express route won't really work...
Messages between the server and client via WebSockets are JSON with actions like GET_ITEMS then a response of GET_ITEMS_SUCCESS with an array of 'items' and for errors: ..._ERROR etc. This is all fine, since it's just 1 to 1 transaction. Though the problem arises when broadcasting (1 to all) to all relevant clients when the server receives an update.
So, I assume it best practice to limit these broadcasts to the clients that are viewing/want the data. So when viewing, for example, the Item page, there is no point in broadcasting updates to the User data since that is only used on the User page.
I haven't been able to find any common practices when dealing with this sort of situation, just a few small outdated/barely used wrappers for ws that just add a few basic functions to leave/join but don't offer much flexibility with implementation.
What I think MIGHT work is to have an object/array for each 'group'/'room', which stores the clients that are currently listening to updates from a given section. So a user would send an action to INIT_LISTEN (& ``) with a param of category, e.g. ITEM for updates and other actions related to items.
TL;DR
What my question really boils down to is: How do I store a reference to a single socket? (ws client object? ws client ID?) Then, can I store this in an object/array to iterate through like below.
const ClientRooms = {
Items: {
{
...ws
}
/* ...rest of the client */
}
}
or
const ClientRooms = {
Items: [ "xyz" ] /* Array of ws ids */
}
I have a "ping--pong" heartbeat function to keep clients active and prevent silent connection failures/disconnections. I can't find if ws.terminate() still fires the ws close event so I can iterate 'group'/'room' the object/array to find and remove instances of that client.
Hi I am using websockets with node js server, the npm module is ws. I have an array where I save all my connections but now I have to separate them so I did multidimensional array something like this:
users[channel1][user_id1] = ws_user_id1_connection
The question is when I have 1 user in multiple channels:
users[channel1][user_id1] = ws_user_id1_connection
users[channel2][user_id1] = ws_user_id1_connection
users[channel3][user_id1] = ws_user_id1_connection
From preformance point of view, is this ok?. or I can accomplish this in some other way? And if I leave it like this, Is that users[channel1],users[channel2],users[channel3], they would be only reference to the ws_user_id1_connection. I mean It's not going to add the all data about ws_user_id1_connection when I create new users[channelNew], but only reference to it. The Idea is that I would like to have something as rooms/channels and in each channel to have some connected users so they can talk each other. Is that the right way? Thank you in advance.
Assuming that channel1 is a chat room, user_id1 is the userid in the room, then yes, that's a good way to implement it, you should not create a different ws per channel. You will just need to add some information to the sent data so the client knows what is the room related to the message, something like:
{
'room': 'channel1',
'from': 'otherUser_id',
'msg': 'some text message'
}
I would recommend not to use channel to refer a room because it can be confused with a ws channel. I´d also change the name of the variable ´users´ as it is not referencing users, I´d leave it like: rooms[room_id1][user_id1] = ws_user_id1_connection
Also, you may want to check Socket.io, it is a good Nodejs library designed for that kind of applications.