return results from a function (javascript, nodejs)


Question

Could anyone help me with this code? I need to return a value form a routeToRoom function:

var sys = require('sys');

function routeToRoom(userId, passw) {
    var roomId = 0;
    var nStore = require('nstore/lib/nstore').extend(require('nstore/lib/nstore/query')());
    var users = nStore.new('data/users.db', function() {

        users.find({
            user: userId,
            pass: passw
        }, (function(err, results) {
            if (err) {
                roomId = -1;
            } else {
                roomId = results.creationix.room;
            }
        }
        ));
    });
    return roomId;
}
sys.puts(routeToRoom("alex", "123"));

But I get always: 0

I guess return roomId; is executed before roomId=results.creationix.room. Could someone help me with this code?

1
22
11/9/2018 8:30:29 PM

function routeToRoom(userId, passw, cb) {
    var roomId = 0;
    var nStore = require('nstore/lib/nstore').extend(require('nstore/lib/nstore/query')());
    var users = nStore.new('data/users.db', function() {
        users.find({
            user: userId,
            pass: passw
        }, function(err, results) {
            if (err) {
                roomId = -1;
            } else {
                roomId = results.creationix.room;
            }
            cb(roomId);
        });
    });
}
routeToRoom("alex", "123", function(id) {
    console.log(id);    
});

You need to use callbacks. That's how asynchronous IO works. Btw sys.puts is deprecated

44
8/31/2011 11:19:01 AM

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