计算云函数内的时间差

Question

在我的 Cloud Firestore 数据库中，总是注册一个用户，数据库存储事件发生的时间：

const p = usersReference.add({ 
    ...,
    registerTime: admin.firestore.FieldValue.serverTimestamp(), 
    ...
});

我的目标是创建另一个云函数，获取用户作为输入并在用户注册后至少 5 天后返回：

export const get_user_timeleft = functions.https.onRequest((request, response) => {
        //useless part of the function...       
            querySnapshot.forEach(function (documentSnapshot) {
                //Here I know that documentSnapshot.data().registerTime 
                //returns whatever is saved in the database.
                //How can I return true or false if there's been 5 
                //or more days since the user registered?
                response.json(TRUE of FALSE);
            })
        }
    })
    .catch(function(error) {
        response.json(error);
    });

});

---

显然我可以再次调用admin.firestore.FieldValue.serverTimestamp() 并尝试减去它们，但我什至不知道它是什么类型。过去我设法将其用作Date，但由于Firebase 说Date 将被弃用，我不知道如何处理它。

Answer 1

如果您想在您的云函数中检查querySnapshot.forEach() 循环返回的每个文档，如果用户注册后至少有 5 天（即today - registerTime > 5），您可以执行以下操作：

export const get_user_timeleft = functions.https.onRequest((request, response) => {
            //useless part of the function...    

            const nowDate = new Date();

            querySnapshot.forEach(function (documentSnapshot) {
                //Here I know that documentSnapshot.data().registerTime 
                //returns whatever is saved in the database.
                //How can I return true or false if there's been 5 
                //or more days since the user registered?

                const elapsedTime = (nowDate.getTime() - documentSnapshot.data().registerTime.getTime());

                const daysDifference = Math.floor(elapsedTime/1000/60/60/24);

                //Check that the difference is more than 5 and then act accordingly
                //It is not crystal clear from your question if there is only one document in the querySnapshot


            })

    })
    .catch(function(error) {
        response.json(error);
    });

});

如果您确定查询只返回一个文档（根据您问题下的 cmets，这似乎是这种情况），您可以这样做：

export const get_user_timeleft = functions.https.onRequest((request, response) => {
            //useless part of the function...    

            const nowDate = new Date();
            let daysDifference;

            querySnapshot.forEach(function (documentSnapshot) {
                //Here I know that documentSnapshot.data().registerTime 
                //returns whatever is saved in the database.
                //How can I return true or false if there's been 5 
                //or more days since the user registered?

                const elapsedTime = (nowDate.getTime() - documentSnapshot.data().registerTime.getTime());

                daysDifference = Math.floor(elapsedTime/1000/60/60/24);            

            });

            if (daysDifference > 5) {
                 response.send({ result: true }); 
            } else {
                 response.send({ result: false }); 
            }


    })
    .catch(function(error) {
        response.json(error);
    });

});