Socket.io

Default namespace

• the default namespace is / and it’s the one Socket.IO clients connect to by default, and the one the server listens to by default.
• Each namespace emits a connection event that receives each Socket instance as a parameter

Custom namespaces

• To set up a custom namespace, you can call the of function on the server-side
• On the client side, you tell Socket.IO client to connect to that namespace
• The namespace is an implementation detail of the Socket.IO protocol, and is not related to the actual URL of the underlying transport, which defaults to /socket.io/…

Rooms

• Within each namespace, you can also define arbitrary channels that sockets can join and leave

Joining and leaving

• You can call join to subscribe the socket to a given channel
• And then simply use to or in (they are the same) when broadcasting or emitting