我目前正在学习如何使用Firebase的新云函数，我遇到的问题是我无法访问我通过AJAX请求编写的函数。我得到了“No 'Access-Control-Allow-Origin'”错误。下面是我写的函数示例:
exports.test = functions.https.onRequest((request, response) => {
response.status(500).send({test: 'Testing functions'});
})
函数位于这个url中:
https://us-central1-fba-shipper-140ae.cloudfunctions.net/test
Firebase文档建议在函数中添加CORS中间件，我尝试过，但对我不起作用:https://firebase.google.com/docs/functions/http-events
我是这样做的:
var cors = require('cors');
exports.test = functions.https.onRequest((request, response) => {
cors(request, response, () => {
response.status(500).send({test: 'Testing functions'});
})
})
我做错了什么?如果你能帮我，我会很感激。
更新:
道格·史蒂文森的回答很有帮助。添加({origin: true})修复了这个问题，我还必须将response.status(500)更改为response.status(200)，这是我一开始完全错过的。
Firebase团队提供了两个示例函数来演示CORS的使用:
具有日期格式的时间服务器
要求认证的HTTPS端点
第二个示例使用与当前使用的cors不同的工作方式。
考虑像这样导入，如示例所示:
const cors = require('cors')({origin: true});
函数的一般形式是这样的
exports.fn = functions.https.onRequest((req, res) => {
cors(req, res, () => {
// your function body here - use the provided req and res from cors
})
});
如果有像我这样的人:如果你想在同一个项目中调用云函数，你可以init firebase sdk并使用onCall方法。它会为你处理一切:
exports.newRequest = functions.https.onCall((data, context) => {
console.log(`This is the received data: ${data}.`);
return data;
})
像这样调用这个函数:
// Init the firebase SDK first
const functions = firebase.functions();
const addMessage = functions.httpsCallable(`newRequest`);
Firebase文档:https://firebase.google.com/docs/functions/callable
如果你不能初始化SDK，以下是其他建议的精髓:
如果在默认位置使用firebase托管和主机，请选择“重写:https://firebase.google.com/docs/hosting/full-config#rewrites”
或者像krishnazden建议的那样使用CORS: https://stackoverflow.com/a/53845986/1293220
没有CORS解决方案对我有效…直到现在!
Not sure if anyone else ran into the same issue I did, but I set up CORS like 5 different ways from examples I found and nothing seemed to work. I set up a minimal example with Plunker to see if it was really a bug, but the example ran beautifully. I decided to check the firebase functions logs (found in the firebase console) to see if that could tell me anything. I had a couple errors in my node server code, not CORS related, that when I debugged released me of my CORS error message. I don't know why code errors unrelated to CORS returns a CORS error response, but it led me down the wrong rabbit hole for a good number of hours...
dr -如果没有CORS解决方案工作，检查您的firebase函数日志并调试任何错误
更新答案:使用cors库与Typescript支持:
安装科尔斯
npm i -S cors
npm i --save-dev @types/cors
index.ts:
import * as cors from "cors";
const corsHandler = cors({ origin: true });
// allow cors in http function
export const myFunction = functions.https.onRequest((req, res) => {
corsHandler(req, res, async () => {
// your method body
});
});
旧的回答:
(不再工作)
找到了一种不导入任何“cors”库的方法来启用cors。它还可以使用Typescript，并在chrome版本81.0中进行了测试。
exports.createOrder = functions.https.onRequest((req, res) => {
// browsers like chrome need these headers to be present in response if the api is called from other than its base domain
res.set("Access-Control-Allow-Origin", "*"); // you can also whitelist a specific domain like "http://127.0.0.1:4000"
res.set("Access-Control-Allow-Headers", "Content-Type");
// your code starts here
//send response
res.status(200).send();
});
