在回調中設置會話值（Node.js，express.js）

Question

如何在回調中設置會話值？ 為什么不起作用？

app.get('/room/:id', function(req, res) {
    var room_id = req.param('id');
    room.getRoom(room_id, function(err, result) {
        if(result.length) {
            req.session.code_room = room_id;
        }
    }); 
    res.render('room.jade');
});

Answer 1

您可能應該將res.render移到回調函數的內部：

app.get('/room/:id', function(req, res) {
    var room_id = req.param('id');
    room.getRoom(room_id, function(err, result) {
        if(result.length && !err) {
            req.session.code_room = room_id;
        } else {
            //sorry...
            req.session.code_room = -1;
        }
        res.render('room.jade');
    }); 
});