Socket Io cheat sheet code example

Example 1: emit cheatsheet

io.on("connection", (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?", (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?");

  // 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 2: socket emit to specific room using nodejs socket.io

io.on('connection', function(socket){  socket.to('some room').emit('some event');});

Example 3: 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 4: socket emit to specific room using nodejs socket.io

io.on('connection', socket => {  socket.on('disconnecting', () => {    const rooms = Object.keys(socket.rooms);    // the rooms array contains at least the socket ID  });  socket.on('disconnect', () => {    // socket.rooms === {}  });});

Example 5: node socket.io send

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');

};