Emit cheatsheet
Server-side
io.on("connection", (socket) => { // basic emit socket.emit(/* ... */); // to all clients in the current namespace except the sender socket.broadcast.emit(/* ... */); // to all clients in room1 except the sender socket.to("room1").emit(/* ... */); // to all clients in room1 and/or room2 except the sender socket.to(["room1", "room2"]).emit(/* ... */); // to all clients in room1 io.in("room1").emit(/* ... */); // to all clients in room1 and/or room2 except those in room3 io.to(["room1", "room2"]).except("room3").emit(/* ... */); // to all clients in namespace "myNamespace" io.of("myNamespace").emit(/* ... */); // to all clients in room1 in namespace "myNamespace" io.of("myNamespace").to("room1").emit(/* ... */); // to individual socketid (private message) io.to(socketId).emit(/* ... */); // to all clients on this node (when using multiple nodes) io.local.emit(/* ... */); // to all connected clients io.emit(/* ... */); // 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. // with acknowledgement socket.emit("question", (answer) => { // ... }); // without compression socket.compress(false).emit(/* ... */); // a message that might be dropped if the low-level transport is not writable socket.volatile.emit(/* ... */); }); |
Client-side
// basic emit socket.emit(/* ... */); // with acknowledgement socket.emit("question", (answer) => { // ... }); // without compression socket.compress(false).emit(/* ... */); // a message that might be dropped if the low-level transport is not writable socket.volatile.emit(/* ... */); |
Reserved events
On each side, the following events are reserved and should not be used as event names by your application:
connect
connect_error
disconnect
disconnecting
newListener
removeListener
// BAD, will throw an error socket.emit("disconnecting"); |
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Licensed under the MIT License.
https://socket.io/docs/v4/emit-cheatsheet