Methods of using socket.io in node.js_node.js

Use socket.io to create a socket.io server. But this server depends on an already created http server.

After the http server is running, use the listen method to attach a socket.io server to the http server.

Copy code The code is as follows:

var sio=require("scoket.io");
var socket=sio.listen(server);

Socket is a socket.io server created based on server.

When the client establishes a connection with the server, the connection event of the socket.io service is triggered.

Copy code The code is as follows:

socket.on("connection",function(socket){
});

The socket parameter in the callback function is the socket port object used to establish a connection between the server and the client.

When a message sent by the client is received, the message event of the socket port object is emitted.

Copy code The code is as follows:

socket.on("message",function(msg){
});

The parameter of the callback function is the message sent by the client.

You can use socket.send(msg) to send a message to the client.

The disconnect event is triggered when the connection between the server and the client is disconnected.

Copy code The code is as follows:

socket.on("disconnect", funciton(){
});

This callback function does not take any parameters.

Server-side server.js code:

Copy code The code is as follows:

var http=require("http");
var sio=require("socket.io");
var fs=require("fs");
var server=http.createServer(function (req,res) {
res.writeHead(200,{"Content-type":"text/html"});
res.end(fs.readFileSync("./index.html"));
});
server.listen(1337);
var socket=sio.listen(server);
socket.on("connection", function (socket) {
console.log("Client establishes connection");
​​socket.send("Hello");
socket.on("message", function (msg) {
console.log("Received a message:" msg);
});
​​socket.on("disconnect", function () {
console.log("Client disconnected.");
});
});

Create client index.html code:

Copy code The code is as follows:

<script><br>         var socket=io.connect();<br> socket.on("message", function (data) {<br> console.log(data);<br> socket.send("Message received.")<br>           });<br>            socket.on("disconnect", function () {<br> console.log("Server side disconnected.");<br>           });<br> </script>

This code:/socket.io/socket.io.js is provided by the server-side socket.io class library, and there is no need to actually place a socket.io.js file on the client side.

In the script file, first use the io.connect() method to connect to the server-side socket.io server.

This method returns a client socket port object that establishes a connection with the server.

When a message sent by the server is received, the message event of the client socket port object is triggered.

Copy code The code is as follows:

socket.on("message",function(msg){
});

msg is the data sent by the server;

You can also use the send() method of the client's socket object to send data to the server.

Copy code The code is as follows:

socket.send(msg);

When the server disconnects, the disconnect event of the client socket port object is triggered,

Copy code The code is as follows:

socket.on("disconnect",function(){
})

This callback function does not use any parameters.

Note:

The client's message mechanism is completely consistent with the server's message processing mechanism. Because socket.io ensures that the client and server share the same API.

Result after running:

When the browser is closed, the connection with the server is disconnected. At this time, the server triggers the disconnect event and the client disconnects.