Send update notification to particular users using socket.io

Question

Following is the code on front end, where storeSelUserId contains user_id to send the message-

FYI - Node Version 1.1.0

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Answer 1

According to what i understand, you need private notification send to only some users. For that, save your users name to whom you want to send and their corresponding socket in different hashes.

username [socket.name] = username to be added;
usersocket [ socket.name ] =socket;

Then to emit the messages to that user only, use

usersocket[ socket.name ].emit('event for send message', ' what you want to send ');

Answer 2

If you want to use your own user ids then there is no way around mapping the socket id to the user id. I assume a client knows its user id from somewhere, so it could send its user id to the server after connection.

Client

socket.on('connection', function (data) {
    socket.emit('setUserId', myUserId);
});

The server saves the socket for each user id.

socket.on('setUserId', function (userId) {
    users[userId]=socket;
});

If you have such a mapping in the server you can send a message just to this client using the user id.

socket.on('send notification', function (userId) {
     users[userId].emit('notification', "important notification message");
});

Edit: Saving the corresponding socket directly is even better.