如何使用Asyn重構Node.js代碼並避免回調地獄

Question

我對Node還是比較陌生，並且正在嘗試學習如何異步或答應或任何使我的代碼更好的方法。 這是我的代碼的示例

router.post('/delete', function (req, res) {
    var bus_id = req.body.selected[0];
        Bus.remove({_id: bus_id}, function (err) {
            if (err) {
                res.json({status: "error", message: "please enter a valid bus_id"});
            } else {
                User.remove({refid:bus_id},function(err){
                    if (err) {
                        res.json({status: "error", message: "bus user wasn't deleted"});
                        return;
                    } else {
                        res.json({status: "success",message: "bus and bus user were deleted"});
                    }
                });
            }
        });
});

我讀過有關異步和承諾的信息，將其應用於代碼的最佳方法是什么？

Answer 1

我個人會去承諾。 它可能看起來像這樣。

router.post('/delete', function (req, res) {
  var bus_id = req.body.selected[0];

  Bus.remove({_id: bus_id}).exec().then(function(bussRemoved) {
    return User.remove({refid: bus_id}).exec();
  }).then(function(userRemoved) {
    res.json({status: "success",message: "bus and bus user were deleted"});
  }).catch(function (err) {
    res.json({status: "error", message: "please enter a valid bus_id"});
  });
});