Is it possible to connect any external application to my sails.js application via WebSockets?
I can use the underlying socket.io embedded in sails.js to talk between the client and server, that's not a problem.
But, I would like to connect another, separate, application to the sails.js server via websockets, and have those two communicate with each other that way, and I am wondering if this is possible?
If so, how can we do this?
Thanks.
Based on SailsJS documentation, we have access to the io object of socket.io, via sails.io.
From that, I just adjusted boostrap.js:
module.exports.bootstrap = function (cb) {
sails.io.on('connection', function (socket) {
socket.on('helloFromClient', function (data) {
console.log('helloFromClient', data);
socket.emit('helloFromServer', {server: 'says hello'});
});
});
cb();
};
Then, in my other nodejs application, which could also be another SailsJS application and I will test that later on, I simply connected and sent a message:
var io = require('socket.io-client');
var socket = io.connect('http://localhost:3000');
socket.emit('helloFromClient', {client: 'says hello'});
socket.on('helloFromServer', function (data) {
console.log('helloFromServer', data);
});
And here are the outputs.
In SailsJS I see:
helloFromClient { client: 'says hello' }
In my client nodejs app I see:
helloFromServer { server: 'says hello' }
So, it seems to be working just fine.
Related
I'm trying to make socket.io-client work in a svelte front end app to talk to an existing API server that already uses socket.io. After a number of challenges, I managed to make this work but I can only get this to work with sveltekit's preview and not in dev mode. Wondered if someone with some knowledge of those could explain why or suggest what I need to do to get it connecting in dev?
svelte 3.34.0
sveltekit next-169
socket.io(-client) 4.2.0
basic code as follows, currently within a file $lib/db.js where I define a few stores that are pulled into the layout for general use..
import { io } from "socket.io-client";
import { browser } from '$app/env';
const initSocket = async () => {
console.log('creating socket...');
let socket = io('http://192.168.1.5:4000', { 'connect timeout': 5000 });
socket.on("connect", () => {
// always works in preview...
console.log('socket created with ID:', socket.id);
});
socket.on("connect_error", (error) => {
// permanently fired in dev...
console.error('Failed to connect', error);
});
socket.on("error", (error) => {
console.error('Error on socket', error);
});
socket.on("foo", data => {
// works in preview when server emits a message of type 'foo'..
console.log("FOO:", data);
});
};
if (browser) {
initSocket();
}
// stores setup and exports omitted..
with svelte-kit preview --host I see the socket creation log message with the socket ID and the same can be seen on the api server where it logs the same ID. The socket works and data is received as expected.
with svelte-kit dev --host however, the log message from socket.on("connect").. is never output and I just see an endless stream of error messages in the browser console from the socket.on("connect_error").. call..
Failed to connect Error: xhr poll error
at XHR.onError (transport.js:31)
at Request.<anonymous> (polling-xhr.js:93)
at Request.Emitter.emit (index.js:145)
at Request.onError (polling-xhr.js:242)
at polling-xhr.js:205
Importantly, there is no attempt to actually contact the server at all. The server never receives a connection request and wireshark/tcpdump confirm that no packet is ever transmitted to 192.168.1.5:4000
Obviously having to rebuild and re-run preview mode on each code change makes development pretty painful, does anyone have insight as to what the issue is here or suggestions on how to proceed?
I've had a similar problem, I solved it by adding this code to svelte.config.js:
const config = {
kit: {
vite: {
resolve: {
alias: {
"xmlhttprequest-ssl": "./node_modules/engine.io-client/lib/xmlhttprequest.js",
},
},
},
},
};
The solution was provided by this comment from the vite issues.
c# winform tries to send node.js socket through socket.
The client is connected to server, but the socket.emit value and socket.on value do not communicate normally.
I'd like to find a solution to this.
I would like to send this name of client to the server as json type data, receive json type data from the server, read it, and send data back to json.
The data of socket.emit and socket.on are not working properly, so the code has been deleted.
c# code
private void socketLogin(string email, string pw)
{
var socket = IO.Socket("http://localhost:3000/login.html");
socket.On(Socket.EVENT_CONNECT, () =>
{
});
var loginjson = new JObject();
loginjson.Add("email", email);
loginjson.Add("password", pw);
socket.Emit("socketlogin", loginjson.ToString());
socket.On("login", (data) => {
MessageBox.Show(data.ToString());
});
}
node.js Code
var server = require('http').Server(app);
var io = require('socket.io')(server);
io.on('connection', function(socket) {
console.log('connection');
socket.on('socketlogin', function(data) {
var testLogin = { 'Login': "success" };
socket.emit('login', data);
});
});
server.listen(app.get('3000'))
in your C# you are making your socket inside a function, but at the end of the function the socket is thrown away because it is only a local variable.
There are many ways to deal with this, but essentially what you want to do is use a thread to handle the socket comms then dispatch things back to your UI thread.
server.js
var express = require('express');
var app = express();
var server = require('http').createServer(app);
var io = require('socket.io')(server);
app.use(express.static(__dirname + '/public'));
io.on('connection', function(client) {
console.log('Client connected...');
client.on('join', function(data) {
console.log(data);
io.emit('messages', 'Hello');
});
});
index.html
<script>
var socket = io.connect('http://localhost:7777');
socket.on('connect', function(data) {
socket.emit('join', 'Hello World from client');
});
socket.on('messages', function(data) {
alert(data);
});
</script>
I tried to implement very basic of Socket.io.
However, data sending from client to server is available but from server to client doesn't work.
In the command running server.js, 'Hello World from client' is printed. However, alert window doesn't work in the web browser.(I've also tried to console.log).
How to solve this?
Editted
I've put server.js codes in the app.get('/', function(req, res)){ ... }
Then, it doesn't work. Why it doesn't work in app.get?
Try this, I hope it works:
io.on('connection', function(client) {
console.log('Client connected...');
client.on('join', function(data) {
console.log(data);
io.emit('join', data); //this code sending data from server to client
});
});
If you're just trying to fetch some data with an Ajax call such as /test, then there is no need to use socket.io. That's just a classic request/response.
app.get('/test', function(req, res) {
// collect your data and then send it as a response
res.json(data);
});
If you're just trying to incorporate data into a web page that is requested, then you can use res.render() with the template engine of your choice (ejs, handlebars, pug, etc...). That would typically look like this:
app.get('/test', function(req, res) {
// collect your data and then pass it to res.render() to render your
// your template using that data
res.render('someTemplateName', data);
});
The main thing that socket.io is useful for is "pushing" data from server to client without a client request. So, if something happened on the server that the client was not aware of and the server wanted to tell the client about it, then socket.io would be used for that. The classic example is a chat app. Person A sends a chat message to the server that is addressed to Person B. The server receives that message and then needs to "push" it to Person B. That would be perfect for an already connected socket.io connection because the server can just push the data directly to the Person B client, something the server can't do with request/response (since there is no request from person B).
If you still think you need socket.io, then please describe exactly what you're trying to do with it (step by step what you're trying to send to the client).
socket.on("message",function (reply_data) {
console.log('inside on message functions ')
console.log(reply_data);
})
please change 'messages' to "message" that worked for me
I want to use the websocket in my RN project. And I did it using the ws at server side and the RN built-in websocket implementation.
But it seems not so convinient since I use socket.io before.
So I tried to use socket.io:
In RN:
import './userAgent'
import io from "socket.io-client/socket.io"
In component:
componentDidMount() {
this.socket = io('https://localhost:4080',{jsonp: false});
this.socket.on('hello', (msg) =>{
this.setState({response:msg})
});
}
In the server:
io.on('connection', function(socket){
socket.emit('hello','hello world')
console.log('a user connected');
socket.on('disconnect',function(){
console.log('user disconnected')
})
})
And in userAgent.js
window.navigator.userAgent = 'react-native';
That is just the result I googled and they said it will work. But for me, the chrome debugger stopped at:
function load() {
var r;
try {
r = exports.storage.debug;
} catch(e) {}
return r;
}
And it says the storage is not defined.
Then I looked into the socket.io.js and find that the exports.storage is window.localStorage. So I disabled the remote js debug, and the code began running.
But the server continues to log : a user connected . as if my RN app is keeping on connecting to the server. And it seems the socket.on() did not work at client side.
react-native version:0.27.2
socket.io-client version:1.4.8
Anyone knows where is going wrong?
Well,finally I found the solution after looking through the socket.io source.
It seems that the socket.io does not use 'websocket' as transport defaultly. It will use the 'polling' in my case, so just explicityly set it :
componentDidMount() {
var socket = io('http://localhost:4080', { jsonp: false, transports: ['websocket'] })
socket.on('hello', (msg) => {
//do something
});
}
Now it works.
But what still confuses me is that in brower client I do not set the transports and it just work well but in react-native it doesn't. Not figured out why.
I want to use sockets in my web app. I don't want to use socket.io library on client-side. It's OK for server-side though. Can I do this?
Now with socket.io on server and pure websocket on client I have destroying non-socket.io upgrade error. I've googled that it means that I have to use socket.io-client library on client-side. Is there any way to avoid that? I don't want client to be tight with this library and use pure html5 websocket instead.
If it's not possible what should I use for server to connect with pure html5 websockets?
If someone is curious here is my server code (coffeescript file)
# Require HTTP module (to start server) and Socket.IO
http = require 'http'
io = require 'socket.io'
# Start the server at port 8080
server = http.createServer (req, res) ->
# Send HTML headers and message
res.writeHead 200, { 'Content-Type': 'text/html' }
res.end "<h1>Hello from server!</h1>"
server.listen 8080
# Create a Socket.IO instance, passing it our server
socket = io.listen server
# Add a connect listener
socket.on 'connection', (client) ->
# Create periodical which ends a message to the client every 5 seconds
interval = setInterval ->
client.send "This is a message from the server! #{new Date().getTime()}"
, 5000
# Success! Now listen to messages to be received
client.on 'message', (event) ->
console.log 'Received message from client!', event
client.on 'disconnect', ->
clearInterval interval
console.log 'Server has disconnected'
And here is a client-side
<script>
// Create a socket instance
socket = new WebSocket('ws://myservername:8080');
// Open the socket
socket.onopen = function (event) {
console.log('Socket opened on client side', event);
// Listen for messages
socket.onmessage = function (event) {
console.log('Client received a message', event);
};
// Listen for socket closes
socket.onclose = function (event) {
console.log('Client notified socket has closed', event);
};
};
</script>
I've found this library, seems OK for my needs https://npmjs.org/package/ws