I'm trying to set up a server that can dynamically create many rooms for many namespaces. I'm currently just trying to broadcast to sockets of a room, when a new socket has joined that room.
So far I have been able to broadcast to a specific namespace and my event listeners on the client receives the message. However when I try to broadcast to a room, of a specific namespace, my event listener doesn't receive that message.
I've turned on the Debugger mode and see the socket.io-client:socket emitting the event with the right payload and event type. So I am not sure what I am missing since the documentation also seems fairly straightforward. Any help would be much appreciated. Below is my code.
Server
const colorNs = io.of('/color');
colorNs.on('connection', (socket) => {
const { id } = socket.handshake.query;
const { id:connId } = socket.conn;
if(id) {
socket.join(id);
socket.broadcast.to(id).emit('user:connect', { id: connId });
}
socket.on('disconnect', () => {
const { id } = socket.handshake.query;
const { id:connId } = socket.conn;
socket.broadcast.to(id).emit('user:disconnect', { id: connId });
});
});
Client
const socket = io('/color?id="123"');
socket.on('user:connect', () => console.log('data', data));
Client - Debug Trace
socket.io-parser decoded 2/color,["user:connect",{"id":"IZTTPidF121JCzf9AAAO"}] as {"type":2,"nsp":"/color","data":["user:connect",{"id":"IZTTPidF121JCzf9AAAO"}]} +1ms
browser.js:133
socket.io-client:socket emitting event ["user:connect",{"id":"IZTTPidF121JCzf9AAAO"}] +3ms
Related
I am using the Node.js ws library, to listen to events in user accounts on a 3rd party API. For each user, I open a websocket to listen to the events in the user's account.
Turns out, the 3rd-party API doesn't provide a userID for each event, so if I have 10 websocket connections to user-accounts, I cannot determine which account an event came from.
I have access to a unique userId prior to starting each of my connections.
Is there a way to append or wrap the websocket connection with the userId identifier, to each connection I make, such that when I receive an event, I can access the custom identifier, and subsequently know which user's account the event came from?
The code below is a mix of real code, and pseudocode (i.e customSocket)
const ws = new WebSocket('wss://thirdparty-api.com/accounts', {
port: 8080,
});
ws.send(
JSON.stringify({
action: 'authenticate',
data: {
oauth_token: access_token,
},
})
);
// wrap and attach data here (pseudocode at top-level)
customSocket.add({userId,
ws.send(
JSON.stringify({
action: 'listen',
data: {
streams: ['action_updates'],
},
})
)
})
// listen for wrapper data here, pseudocode at top level
customSocket.emit((customData) {
ws.on('message', function incoming(data) {
console.log('incoming -> data', data.toString());
})
console.log('emit -> customData', customData);
})
Looking at the socket.io library, the namespace feature may solve for this, but I can't determine if that's true or not. Below is an example in their documentation:
// your application has multiple tenants so you want to dynamically create one namespace per tenant
const workspaces = io.of(/^\/\w+$/);
workspaces.on('connection', socket => {
const workspace = socket.nsp;
workspace.emit('hello');
});
// this middleware will be assigned to each namespace
workspaces.use((socket, next) => {
// ensure the user has access to the workspace
next();
});
I found a solution to this which is fairly simple. First create a message handler function:
const eventHandler = (uid, msg) => {
console.log(`${uid} did ${msg}`);
};
Then, when you create the websocket for the given user, wrap the .on event with the handler:
const createSocketForUser = (uid, eventHandler) => {
const socket = new WebSocket(/* ... */);
socket.onmessage = (msg) => {
eventHandler(uid, msg)
};
return socket;
}
I am trying to integrate socket.io with strapi. But unfortunately I have been unable to do so without any proper tutorial or documentation covering this aspect.
I followed along with the only resource I found online which is:
https://medium.com/strapi/strapi-socket-io-a9c856e915a6
But I think the article is outdated. I can't seem to run the code mentioned in it without running into tonnes of errors.
Below is my attempt to implement it and I have been trying to connect it through a chrome websocket plugin smart websocket client But I am not getting any response when I try to run the server.
I'm totally in the dark. Any help will be appreciated
module.exports = ()=> {
// import socket io
var io = require('socket.io')(strapi.server)
console.log(strapi.server) //undefined
// listen for user connection
io.on('connect', socket => {
socket.send('Hello!');
console.log("idit")
// or with emit() and custom event names
socket.emit('greetings', 'Hey!', { 'ms': 'jane' }, Buffer.from([4, 3, 3, 1]));
// handle the event sent with socket.send()
socket.on('message', (data) => {
console.log(data);
});
// handle the event sent with socket.emit()
socket.on('salutations', (elem1, elem2, elem3) => {
console.log(elem1, elem2, elem3);
});
});
};
So I found the solution. Yay. I'll put it here just in case anybody needs it.
boostrap.js
module.exports = async () => {
process.nextTick(() =>{
var io = require('socket.io')(strapi.server);
io.on('connection', async function(socket) {
console.log(`a user connected`)
// send message on user connection
socket.emit('hello', JSON.stringify({message: await strapi.services.profile.update({"posted_by"})}));
// listen for user diconnect
socket.on('disconnect', () =>{
console.log('a user disconnected')
});
});
strapi.io = io; // register socket io inside strapi main object to use it globally anywhere
})
};
Found this at: https://github.com/strapi/strapi/issues/5869#issuecomment-619508153_
Apparently, socket.server is not available when the server starts. So you have to make use of process.nextTick that waits for the socket.server to initialize.
I'll also add a few questions that I faced when setting this up.
How do i connect from an external client like nuxt,vue or react?
You just have to connect through "http://localhost:1337" that is my usual address for strapi.
I am using nuxt as my client side and this is how set up my socketio on the client side
I first installed nuxt-socket-io through npm
Edited the nuxt.config file as per it's documention
modules:[
...
'nuxt-socket-io',
...
],
io: {
// module options
sockets: [
{
name: 'main',
url: 'http://localhost:1337',
},
],
},
And then i finally added a listener in one of my pages.
created() {
this.socket = this.$nuxtSocket({})
this.socket.on('hello', (msg, cb) => {
console.log('SOCKET HI')
console.log(msg)
})
},
And it works.
A clean way to integrate third-party services into Strapi is to use hooks. They are loaded once during the server boot. In this case, we will create a local hook.
The following example has worked with strapi#3.6.
Create a hook for socket.io at ./hooks/socket.io/index.js
module.exports = strapi => {
return {
async initialize() {
const ioServer = require('socket.io')(strapi.server, {
cors: {
origin: process.env['FRONT_APP_URL'],
methods: ['GET', 'POST'],
/* ...other cors options */
}
})
ioServer.on('connection', function(socket) {
socket.emit('hello', `Welcome ${socket.id}`)
})
/* HANDLE CLIENT SOCKET LOGIC HERE */
// store the server.io instance to global var to use elsewhere
strapi.services.ioServer = ioServer
},
}
}
Enable the new hook in order for Strapi to load it - ./config/hook.js
module.exports = {
settings: {
'socket.io': {
enabled: true,
},
},
};
That's done. You can access the websocket server inside ./config/functions/bootstrap.js or models' lifecycle hooks.
// ./api/employee/models/employee.js
module.exports = {
lifecycles: {
async afterUpdate(result, params, data) {
strapi.services.ioServer.emit('update:employee', result)
},
},
};
For those who are looking the answer using Strapi version 4
var io = require("socket.io")(strapi.server.httpServer)
I am new to web-sockets. I was reading this article on medium and in a part of the client code, the code disconnects the socket every time a new message is emitted.
Why is it so? Does this have some design advantage, is this how it is done?
Why not leave the socket connected for more message streams?
-----EDIT------
Here is the code that I am talking about. The code is from this blog
newMessageReceived() {
const observable = new Observable<{ user: String, message: String}>(observer => {
this.socket.on('new message', (data) => {
observer.next(data);
});
return () => {
// Why is the coder disconnecting the socket here?
this.socket.disconnect();
};
});
return observable;
}
I'm trying to setup socket.io and here is part of my server.js
const app = require('express')();
const http = require('http').Server(app);
const io = require('socket.io')(http, { path: '/websocket', origins:'*:*' });
io.on('connection', (socket) => {
socket.send('Hi');
socket.on('message', (message) => {
console.log(message);
socket.emit('hello', `New: ${message}`);
});
console.log('a user connected');
});
http.listen(3030, function(){
console.log('listening on *:3030');
});
and my simple client:
var socket = io('https://*******.com', {
secure: true,
path: '/websocket'
});
const input = document.getElementById('text');
const button = document.getElementById('button');
const msg = document.getElementById('msg');
button.onclick = () => {
socket.emit('message', input.value);
socket.on('hello', (text) => {
const el = document.createElement('p');
el.innerHTML = text;
msg.appendChild(el);
})
}
And if I'll click for third time I receive a 3 messages back and so on. What I'm doing wrong? I wish to send message to the server and receive modified message back.
I'm new in web sockets.
Any help appreciated.
P.S. socket.io v2.0.1
You are adding a socket.on() event handler each time the button is clicked. So, after the button has been clicked twice, you have duplicate socket.on() event handlers. When the event comes back, your two event handlers will each get called and you will think you are getting duplicate messages. Actually, it's just one message, but with duplicate event handlers.
You pretty much never want to add an event handler inside another event handler because that leads to this sort of build-up of duplicate event handlers. You don't describe (in words) exactly what you're code is trying to do so I don't know exactly what alternative to suggest. Usually, you set up the event handlers first, just once, when the socket is connected and then you will never get duplicate handlers.
So, perhaps it's as simple as changing this:
button.onclick = () => {
socket.emit('message', input.value);
socket.on('hello', (text) => {
const el = document.createElement('p');
el.innerHTML = text;
msg.appendChild(el);
})
}
to this:
button.onclick = () => {
socket.emit('message', input.value);
}
socket.on('hello', (text) => {
const el = document.createElement('p');
el.innerHTML = text;
msg.appendChild(el);
});
If you are using Angular and (probably) embedding the Socket in a Service (simpleton) you are creating a persistent listener in ngOnInit every time you load a page.
You need to create some kind of flag to know if the listener was already created in the Service from another instance of your page.
How can you detect that you received a message on a socket.io connection that you do not have a handler for?
example:
// client
socket.emit('test', 'message');
// server
io.on('connection', function (socket) {
console.log('connection received...');
// logs all messages
socket.conn.on('message', function(data) {
console.log('this gets every message.');
console.log('how do I get just the ones without explicit handlers?');
});
socket.on('other' function(data) {
console.log('expected message');
});
}
By accessing the internals of the socket object you can determine what events it is currently listening for. You can use this server-side code to see if the current message is being handled.
io.on('connection', (socket) => {
console.log('A user connected.');
socket.on('disconnect', () => {
console.log('A user disconnected.');
});
socket.on('chat', (msg) => {
console.log('message: ' + msg);
io.emit('chat', msg);
});
socket.conn.on('message', (msg) => {
if(!Object.keys(socket._events).includes(msg.split('"')[1])) {
console.log(`WARNING: Unhandled Event: ${msg}`);
}
});
}
Once connected I am handling two events, 'disconnect' and 'chat'. After that I define a handler that catches all messages with socket.conn.on(...).
The message it receives is going to be a string that looks something like this: '2["myEventName","param1","param2"]'. By splitting it along the double quotes we can get the event name.
We then peek into the internals of socket to find all the keys of socket._events, which happen to be the event name strings. If this collection of strings includes our event name, then another handler will take care of it, and we don't have to.
You can test it from the console in the browser. Run socket.emit('some other event') there and you should see your warning come up in the server console.
IMPORTANT NOTE: Normally you should not attempt to externally modify any object member starting with an underscore. Also, expect that any data in it is unstable. The underscore indicates it is for internal use in that object, class or function. Though this object is not stable, it should be up to date enough for us to use it, and we aren't modifying it directly.
Tested with SocketIO version 2.2.0 on Chrome.
I didn't find a way to do it like socket.io, but using a simple js function to transform message into json it's doing the same job. Here you can try this:
function formatMessage(packetType, data) {
var message = {'packetType': packetType, 'data': data}
return JSON.stringify(message)
}
With:
socket.on('message', function(packet){
packet = JSON.parse(packet)
switch (packet.packetType) {
case 'init':
...
and
socket.send(formatMessage('init', {message}));
I would do so, of course it is the abstract code ... you would have to implement all the listeners and the logic to get the ids of the users to work
Client
var currentUser = {
id: ? // The id of current user
};
var socketMessage = {
idFrom: currentUser.id,
idTo: ?, // Some user id value
message: 'Hello there'
};
socket.emit('message', socketMessage);
socket.on('emitedMessage' + currentUser.id, function(message) {
// TODO: handle message
});
Server
io.on('connection', function (socket) {
// Handle emit messages
socket.on('message', function(socketMessage) {
// With this line you send the message to a specific user
socket.emit('emitedMessage-' + socketMessage.idTo, {
from: socketMessage.idFrom,
message: socketMessage.message
});
});
});
More info: http://socket.io/docs/