如何在 React 的 firebase firestore 中获取/生成当前时间戳

Question

我在我当前的项目中使用 Firebase Firestore 数据库，并且必须从我的前端添加文档，为此我需要当前时间戳。

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

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

Answer 1

那么你需要从 firebase 导入 firestore，不要使用 firebase.firestore.FieldValue.serverTimeStamp 它不会工作

这是工作示例

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;

另请注意，尽管@shubham Takode 的回答是正确的，但客户端不会填充 firebase firestore 当前时间戳，因此尝试在 react useState() 管理中使用它对您没有好处。

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*/})