Advanced Node.js Development

Updating the users list when someone left the chatroom

The first one is going to update the user list and the second one is going to print a little message, like Andrew has left the room. The first one is going to take the user room property as the only argument, user.room stores the room string, we're going to provide that for both, and now we can start emitting our events.

I'm going to emit the updateUserList event first, inside quotes, updateUserList, and we're going to go ahead and call the exact same method we did right up above, users.getUserList, passing in the room, user.room:

if (user){  io.to(user.room).emit('updateUserList', users.getUserList(user.room));  io.to(user.room).emit();}

Now when someone leaves a room they're going to ...