在 react-native expo 应用程序中使用初始化 firestore 的正确方法

Question

已经看到在 react-native 应用程序中初始化 firestore 的两种不同方法，并且想知道两者之间的区别是什么。 firestore 文档中显示的方法 (https://firebase.google.com/docs/firestore/quickstart#initialize) 看起来像

const admin = require('firebase-admin');
const functions = require('firebase-functions');

admin.initializeApp(functions.config().firebase);

export fs = admin.firestore();

而“firebase”方式（如在本博​​文中看到的：https://forums.expo.io/t/open-when-an-expo-firebase-firestore-platform/4126/29），这是我目前使用并且似乎可以工作的方式，看起来像

import * as firebase from 'firebase';
import 'firebase/firestore';//for using firestore functions, see https://stackoverflow.com/a/50684682/8236733
import { firebaseConfig } from './firebase-credentials';//WARN: gitignored, exports object containing firebase (web)app credentials


// Initialize Firebase
// why in separate file? see https://github.com/zeit/next.js/issues/1999 and https://ilikekillnerds.com/2018/02/solving-issue-firebase-app-named-default-already-exists/

// firebase.initializeApp(firebaseConfig);

try {
    firebase.initializeApp(firebaseConfig)

    /*WARN:
    @firebase/firestore:, Firestore (5.0.4): 
    The behavior for Date objects stored in Firestore is going to change
    AND YOUR APP MAY BREAK.
    To hide this warning and ensure your app does not break, you need to add the
    following code to your app before calling any other Cloud Firestore methods:

    const firestore = firebase.firestore();
    const settings = {timestampsInSnapshots: true};
    firestore.settings(settings);

    With this change, timestamps stored in Cloud Firestore will be read back as
    Firebase Timestamp objects instead of as system Date objects. So you will also
    need to update code expecting a Date to instead expect a Timestamp. For example:

        // Old:
        const date = snapshot.get('created_at');
        // New:
        const timestamp = snapshot.get('created_at');
        const date = timestamp.toDate();

    Please audit all existing usages of Date when you enable the new behavior. In a
    future release, the behavior will change to the new behavior, so if you do not
    follow these steps, YOUR APP MAY BREAK.
    */
    const fsSettings = {/* your settings... */ timestampsInSnapshots: true};
    firebase.firestore().settings(fsSettings)
} catch (err) {
    // we skip the "already exists" message which is
    // not an actual error when we're hot-reloading
    if (!/already exists/.test(err.message)) {
        console.error('Firebase initialization error', err.stack)
    }
}

export const fs = firebase.firestore()

链接到的帖子是我能找到其他人这样做的唯一实例，但它再次对我有用（可以读取和写入到 Firestore）。

对使用 firebase/firestore 非常陌生，希望使用更“正确”的方法。以这些不同的方式在应用程序中初始化 firestore 有什么区别吗？

Answer 1

进口：

import * as firebase from 'firebase';
import 'firebase/firestore';

然后

const db = firebase.firestore();

Answer 2

https://github.com/invertase/react-native-firebase

这是连接到适用于 iOS 和 Android 的原生 Firebase SDK 的 JavaScript 桥梁，因此 Firebase 将在原生线程上运行。 它提供了 react-native 应用程序与 firebase 集成的分步说明。 一件重要的事情是你必须考虑你的 react-native 版本和 firebase sdk 版本。

Answer 3

他们做同样的事情吗？第一个简单地通过声明来完成它，而 expo 通过声明它内联来完成它。你可以随心所欲地做，但他们都做同样的事情