socket io emit to specific client code example
Example 1: socket.io emit to all other clients
// sending to sender-client only
socket.emit('message', "this is a test");
// sending to all clients, include sender
io.emit('message', "this is a test");
// sending to all clients except sender
socket.broadcast.emit('message', "this is a test");
// sending to all clients in 'game' room(channel) except sender
socket.broadcast.to('game').emit('message', 'nice game');
// sending to all clients in 'game' room(channel), include sender
io.in('game').emit('message', 'cool game');
// sending to sender client, only if they are in 'game' room(channel)
socket.to('game').emit('message', 'enjoy the game');
// sending to all clients in namespace 'myNamespace', include sender
io.of('myNamespace').emit('message', 'gg');
// sending to individual socketid
socket.broadcast.to(socketid).emit('message', 'for your eyes only');
// list socketid
for (var socketid in io.sockets.sockets) {}
OR
Object.keys(io.sockets.sockets).forEach((socketid) => {});
Example 2: socket io emit from socket instance or server
socket.emit('message', "this is a test"); //sending to sender-client only
socket.broadcast.emit('message', "this is a test"); //sending to all clients except sender
socket.broadcast.to('game').emit('message', 'nice game'); //sending to all clients in 'game' room(channel) except sender
socket.to('game').emit('message', 'enjoy the game'); //sending to sender client, only if they are in 'game' room(channel)
socket.broadcast.to(socketid).emit('message', 'for your eyes only'); //sending to individual socketid
io.emit('message', "this is a test"); //sending to all clients, include sender
io.in('game').emit('message', 'cool game'); //sending to all clients in 'game' room(channel), include sender
io.of('myNamespace').emit('message', 'gg'); //sending to all clients in namespace 'myNamespace', include sender
socket.emit(); //send to all connected clients
socket.broadcast.emit(); //send to all connected clients except the one that sent the message
socket.on(); //event listener, can be called on client to execute on server
io.sockets.socket(); //for emiting to specific clients
io.sockets.emit(); //send to all connected clients (same as socket.emit)
io.sockets.on() ; //initial connection from a client.
Example 3: socket io emit to socket id
io.to(socketid).emit('message', 'for your eyes only');
Example 4: socket emit to specific room using nodejs socket.io
io.on('connection', function(socket){ socket.to('some room').emit('some event');});
Example 5: socket emit cheat sheet
io.on('connect', onConnect);function onConnect(socket){ // sending to the client socket.emit('hello', 'can you hear me?', 1, 2, 'abc'); // sending to all clients except sender socket.broadcast.emit('broadcast', 'hello friends!'); // sending to all clients in 'game' room except sender socket.to('game').emit('nice game', "let's play a game"); // sending to all clients in 'game1' and/or in 'game2' room, except sender socket.to('game1').to('game2').emit('nice game', "let's play a game (too)"); // sending to all clients in 'game' room, including sender io.in('game').emit('big-announcement', 'the game will start soon'); // sending to all clients in namespace 'myNamespace', including sender io.of('myNamespace').emit('bigger-announcement', 'the tournament will start soon'); // sending to a specific room in a specific namespace, including sender io.of('myNamespace').to('room').emit('event', 'message'); // sending to individual socketid (private message) io.to(socketId).emit('hey', 'I just met you'); // WARNING: `socket.to(socket.id).emit()` will NOT work, as it will send to everyone in the room // named `socket.id` but the sender. Please use the classic `socket.emit()` instead. // sending with acknowledgement socket.emit('question', 'do you think so?', function (answer) {}); // sending without compression socket.compress(false).emit('uncompressed', "that's rough"); // sending a message that might be dropped if the client is not ready to receive messages socket.volatile.emit('maybe', 'do you really need it?'); // specifying whether the data to send has binary data socket.binary(false).emit('what', 'I have no binaries!'); // sending to all clients on this node (when using multiple nodes) io.local.emit('hi', 'my lovely babies'); // sending to all connected clients io.emit('an event sent to all connected clients');};
Example 6: socket io emit to specific client
Let me make it simpler with socket.io rooms. request a server
with a unique identifier to join a server. here we are using
an email as a unique identifier.
Client Socket.io
socket.on('connect', function () {
socket.emit('join', {email: user@example.com});
});
When the user joined a server, create a room for that user
Server Socket.io
io.on('connection', function (socket) {
socket.on('join', function (data) {
socket.join(data.email);
});
});
Now we are all set with joining. let emit something to from the
server to room, so that user can listen.
Server Socket.io
io.to('[email protected]').emit('message', {msg: 'hello world.'});
Let finalize the topic with listening to message event to the
client side
socket.on("message", function(data) {
alert(data.msg);
});
The reference from Socket.io rooms