我在向 firebase
数据库发送数据时出现了错误:
从来源 'http://localhost:3030' 访问 'https://us-central1-pwagram-f39a5.cloudfunctions.net/storePostData' 被 CORS 策略阻止:响应 preflight 请求无法通过访问控制检查:请求的资源上没有 'Access-Control-Allow-Origin' 标头。如果不透明响应符合您的需求,请将请求的模式设置为 'no-cors',以禁用 CORS 获取资源。
当我部署到 firebase
后,更改端点时,我遇到了这个问题。但仅在本地主机上运行时才会出现错误。由于我仍在使用它进行开发,因此需要使其在本地主机上工作。
首先,我输入命令:npm install firebase-admin cors --save
下面是文件夹 firebase
的 package.json:
{
"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
}
这里是我所需的“cors”模块的 index.js 文件:
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});
});
});
});
这是使用
firebase
函数的sw.js函数,但没有工作:
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);
});
}
})
);
}
});
当我将https://myFirebaseFUnctionLink/storePostData更改为普通的firebase数据库链接.json
时,它可以正常工作。
这个错误发生在firebase
函数中:
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)
const cors = require('cors')({ origin: "*", credentials: true, methods: "GET" });
这段代码对我很有效。 - Slava Rozhnevconst cors = require('cors')({ origin: "*", credentials: true, methods: "GET" });
? - Ahmad Alfan Juniyanto