如何在 React 的 firebase firestore 中獲取/生成當前時間戳

Question

我在我當前的項目中使用 Firebase Firestore 數據庫，並且必須從我的前端添加文檔，為此我需要當前時間戳。

import * as firebase from "firebase";
import React, {useState} from 'react';

const [time, setTime] = useState({''}) //here i need current timestamp from firebase.

Answer 1

那么你需要從 firebase 導入 firestore，不要使用 firebase.firestore.FieldValue.serverTimeStamp 它不會工作

這是工作示例

import {firestore} from "firebase";

const timestamp = firestore.FieldValue.serverTimestamp();

Answer 2

firebase.initializeApp(firebaseConfig);
const projectFirestore = firebase.firestore();
const timestamp = firebase.firestore.FieldValue.serverTimestamp;

Answer 3

firebase.initializeApp(firebaseConfig); const timestamp = firebase.firestore.FieldValue.serverTimestamp;

另請注意，盡管@shubham Takode 的回答是正確的，但客戶端不會填充 firebase firestore 當前時間戳，因此嘗試在 react useState() 管理中使用它對您沒有好處。

import * as firebase from "firebase";
import React, {useState} from 'react';

firebase.firestore
    .collection('user')
    .doc('userid1')
    .set({
           username: "first user",
           email: "user@email.com",
           time: firebase.firestore.FieldValue.serverTimestamp() // This sets a placeholder in your record that get authomatically populated with the serverTime once it gets to your firestore db.
    }).then(/*do somethings on success*/).catch(err => {/*do somethings on err*/})