javascript - CORS BLOCKED 'Access-Control-Allow-Origin' Firebase 功能不允许

Question

向 firebase 发送数据时出错数据库:

Access to fetch at 'https://us-central1-pwagram-f39a5.cloudfunctions.net/storePostData' from origin 'http://localhost:3030' 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. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled

我在使用 cors 更改端点时遇到了这个问题部署到 firebase 后.但是在本地主机上运行时只有一个错误。我需要它才能在 localhost 上工作，因为我仍在使用它进行开发。

首先，我运行: npm install firebase-admin cors --save
这是我的 包.json 在文件夹 firebase功能:

{
  "name": "functions",
  "description": "Cloud Functions for Firebase",
  "scripts": {
    "lint": "eslint .",
    "serve": "firebase serve --only functions",
    "shell": "firebase functions:shell",
    "start": "npm run shell",
    "deploy": "firebase deploy --only functions",
    "logs": "firebase functions:log"
  },
  "engines": {
    "node": "8"
  },
  "dependencies": {
    "cors": "^2.8.5",
    "firebase-admin": "^8.9.1",
    "firebase-functions": "^3.3.0"
  },
  "devDependencies": {
    "eslint": "^5.12.0",
    "eslint-plugin-promise": "^4.0.1",
    "firebase-functions-test": "^0.1.6"
  },
  "private": true
}

这里是 index.js 文件我需要 cors 模块:

var functions = require('firebase-functions');
var admin = require('firebase-admin');
const cors = require('cors')({origin: true});


exports.storePostData = functions.https.onRequest(function(request, response) {
 return cors(function(request, response) {

    admin.database().ref('posts').push({
        id: request.body.id,
        title: request.body.title,
        location: request.body.location,
        image: request.body.image
    })
        .then(function() {
            return response.status(201).json({message: 'Data stored', id:request.body.id});
        })
        .catch(function(err) {
           return response.status(500).json({error: err});
        });
 });
});

这是我的 sw.js 使用函数 firebase 的函数，但不工作:

self.addEventListener('sync', function(event) {
  console.log('[Service Worker] Background syncing', event);
  if (event.tag === 'sync-new-posts') {
    console.log('[Service Worker] Syncing new Posts');
    event.waitUntil(
      readAllData('sync-posts')
        .then(function(data) {
          for (var dt of data) {
            fetch('https://myFirebaseFUnctionLink/storePostData', {
              method: 'POST',
              headers: {
                'Content-Type': 'application/json',
                'Accept': 'application/json'
              },
              body: JSON.stringify({
                id: dt.id,
                title: dt.title,
                location: dt.location,
                image: 'https://myfirebaselink/'
              })
            })
              .then(function(res) {
                console.log('Sent data', res);
                if (res.ok) {
                  deleteItemFromData('sync-posts', dt.id); // Isn't working correctly!
                }
              })
              .catch(function(err) {
                console.log('Error while sending data', err);
              });
          }

        })
    );
  }
});

当我更改 https://myFirebaseFUnctionLink/storePostData使用正常的 firebase 数据库链接 .json它的工作正常。

此错误发生在 firebase功能 :

TypeError: Cannot read property 'origin' of undefined
    at /srv/node_modules/cors/lib/index.js:219:40
    at optionsCallback (/srv/node_modules/cors/lib/index.js:199:9)
    at corsMiddleware (/srv/node_modules/cors/lib/index.js:204:7)
    at /srv/index.js:9:9
    at cloudFunction (/srv/node_modules/firebase-functions/lib/providers/https.js:49:9)
    at /worker/worker.js:783:7
    at /worker/worker.js:766:11
    at _combinedTickCallback (internal/process/next_tick.js:132:7)
    at process._tickDomainCallback (internal/process/next_tick.js:219:9)

Answer 1

我有同样的问题。重点是 cors 方法的语法。它需要 3 个参数:req、res、一个函数

return cors(req, res, function () {
        admin
            .database()
            .ref('posts')
            .push(req.body)
            .then(function () {
                return res.status(201).json({
                    message: 'Data stored',
                    id: req.body.id,
                });
            })
            .catch(function (err) {
                return res.status(500).json({
                    error: err,
                });
            });
    });