Storing the return value of node.js setTimeout in redis

Question

I\'m using setTimeout in Node.js and it seems to behave differently from client-side setTimeout in that it returns an object instead of a number. I wan

Answer 1

I was attempting to do the same thing as the OP. My solution was to set the timeout with a conditional check on a new key inside the timeout in my disconnect handler:

redis.hset("userDisconnecting:" + userId, "disconnect", 1);

setTimeout(function() {
    redis.hget("userDisconnecting:" + userId, "disconnect",
     function(err, result) {
        if (result.toString() === "1") {
           //do stuff, like notify other clients of the disconnect.
        }
    });
}, 10000);

Then, when the client connects again, I set that key to 0, so the stuff that needs to fire on true disconnect doesn't happen:

redis.hset("userDisconnecting:" + userId, "disconnect", 0);

The timeouts themselves aren't persistent across server restarts, but you could solve that by kicking off a sweeper method on startup. Connected clients would come back "online" pretty quickly.