在 Firebase Cloud 功能中启用 Cors [英] Enable Cors in Firebase Cloud Function

问题描述

我已经编写了一些云函数并部署了它们，现在我正在尝试使用我的 Angular 应用程序访问这些 API，但我收到了这个错误

I have written some cloud functions and deployed them now i am trying to hit those APIs using my Angular application but i am getting this error

CORS 策略已阻止从源http://localhost:4200"访问xxxxxxxxxxxxxxxxxxxxxxxx"处的 XMLHttpRequest:对预检请求的响应未通过访问控制检查:请求的资源上不存在Access-Control-Allow-Origin"标头.

Access to XMLHttpRequest at 'xxxxxxxxxxxxxxxxxxxxxxxx' from origin 'http://localhost:4200' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

我知道我必须在我的云功能中启用 cors，但我以前从未这样做过，所以如果你们能告诉我该怎么做，那就太好了?我确实检查了 this 线程，但我对我在哪里有点困惑需要初始化cors，我是否也需要安装它的依赖项，我需要在我的云功能中在哪里启用它?这是我的云功能

I know i have to enable cors in my cloud function but i have never done that before so would be awesome if you guys could tell me how to do that? I did checked this thread but i am a little bit confused as to where i need to initialize the cors and do i need to install its dependency too and where do i need to enable it in my cloud function? Here is my cloud function

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


const admin = require("firebase-admin");

const bodyParser = require("body-parser");


admin.initializeApp();

const db = admin.firestore();

const usersCollection = db.collection("users");

exports.addUser = functions.https.onRequest((req, res) => {
    if (req.body.username != null && req.body.firstname != null && req.body.lastname != null && req.body.addr1 != null && req.body.addr2 != null || req.body.username != undefined && req.body.firstname != undefined && req.body.lastname != undefined && req.body.addr1 != undefined && req.body.addr2 != undefined ) {
        let docId = Math.floor(Math.random() * (99999 - 00000));
        let newUser = {
            "username": req.body.name,
            "firstname": req.body.firstname,
            "lastname": req.body.lastname,
            "addr1": req.body.addr1,
            "addr2": req.body.addr2,
        }
        usersCollection.add(newUser).then(snapshot => {
            res.send(200, {
                "message": "User was successfully created"
            })
        });


    } else {
        res.send(400, {
            "message": "All fields are required"
        })
    }
});

推荐答案

有两种方法可以解决这个问题

There are two ways to solve this

1. 使用外部库处理OPTIONS调用

cors

1. 手动处理OPTIONS调用

从headers获取请求方法

检查方法是否为OPTIONS

使用 200 状态码解析 API.

Resolve the API with 200 status code.

 exports.addUser = functions.https.onRequest((req, res) => {

res.set('Access-Control-Allow-Origin', '*');
res.set('Access-Control-Allow-Methods', 'GET, PUT, POST, OPTIONS');
res.set('Access-Control-Allow-Headers', '*');

 if (req.method === 'OPTIONS') {
   res.end();
}

else{
        if (req.body.username != null && req.body.firstname != null && req.body.lastname != null && req.body.addr1 != null && req.body.addr2 != null || req.body.username != undefined && req.body.firstname != undefined && req.body.lastname != undefined && req.body.addr1 != undefined && req.body.addr2 != undefined ) {
            let docId = Math.floor(Math.random() * (99999 - 00000));
            let newUser = {
                "username": req.body.name,
                "firstname": req.body.firstname,
                "lastname": req.body.lastname,
                "addr1": req.body.addr1,
                "addr2": req.body.addr2,
            }
            usersCollection.add(newUser).then(snapshot => {
                res.send(200, {
                    "message": "User was successfully created"
                })
            });


        } else {
            res.send(400, {
                "message": "All fields are required"
            })
        }
}
    });

这篇关于在 Firebase Cloud 功能中启用 Cors的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！