问题

Node Server

var app = express();                 

app.use(function(req, res, next) {
res.header('Access-Control-Allow-Credentials', true);
res.header('Access-Control-Allow-Origin', req.headers.origin);
res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
res.header('Access-Control-Allow-Headers', 'X-Requested-With, X-HTTP-Method-Override, Content-Type, Accept');
if ('OPTIONS' == req.method) {
     res.send(200);
 } else {
     next();
 }
});

React JS Fetch

function request(url, options) {
  return fetch(url, options)
    .then(checkStatus)
    .then(parseJSON);
}

export function* login() {
  const username = yield select(makeSelectUsername());
  const password = yield select(makeSelectPassword());

  const requestURL = 'http://myurlhere.com:1337/user/login/';

  const requestOptions = {
    method: 'POST',
    mode: 'cors',
    headers: {
      'Accept': 'application/json',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify(
      {username: username,
      password: password}
    )
  }

  try {
    const result = yield call(request, requestURL, requestOptions);

    yield put(loginApiCallSuccess(result));
  } catch (err) {
    yield put(loginApiCallFailure(err));
  }
}

I need help determining what is wrong with my request or server side handling where chrome is cancelling my requests after preflight failure, aka why is my preflight request failing.

I am running the react on localhost and connecting to a remote server with a different url.

From what I can tell the preflight request is failing then chrome is cancelling the request. However when I ran the request locally the login was still hitting the login route on the node side successfully.

When stepping through the code I get a 400 error from the services on the actual call after the preflight call. If I run the call and don't step through I get a (canceled) in the network tab of dev tools. However the call is successful on the server side each time.

General
Request URL:http://jenkins.murmillosoftware.com:1337/user/register/
Request Method:POST
Status Code:400 Bad Request
Remote Address:52.5.222.29:1337
Referrer Policy:no-referrer-when-downgrade

Response Headers
view source
Access-Control-Allow-Credentials:true
Access-Control-Allow-Headers:X-Requested-With, X-HTTP-Method-Override, Content-Type, Accept, Origin
Access-Control-Allow-Methods:GET,PUT,POST,DELETE
Access-Control-Allow-Origin:http://127.0.0.1:3000
Connection:keep-alive
Content-Length:47
Content-Type:application/json; charset=utf-8
Date:Wed, 16 Aug 2017 22:24:48 GMT
ETag:W/"2f-vn6Bxm14Gkpb5HFTCsgU2h3Nq3o"
set-cookie:connect.sid=s%3AjPVtqIoi6zy0QPmhfFkprFObfwj_J-Lw.sPvW3qRc1Vwj4R6qFBtW0oXykF68Qn%2FAwmLCWrg51qc; Path=/; HttpOnly
X-Powered-By:Express

Request Headers
view source
Accept:application/json
Accept-Encoding:gzip, deflate
Accept-Language:en-US,en;q=0.8
Cache-Control:no-cache
Connection:keep-alive
Content-Length:44
Content-Type:application/json
Host:jenkins.murmillosoftware.com:1337
Origin:http://127.0.0.1:3000
Pragma:no-cache
Referer:http://127.0.0.1:3000/login?
User-Agent:Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.90 Safari/537.36

Request Payload
view source
{username: "fdasfas", password: "asdfasdf"}
password
:
"asdfasdf"
username
:
"fdasfas"

回答1:

have you ever tried express/cors i recently also had problem with access allow origin then i download express/cors from

npm install cors

then add in your program

var express = require('express')
var cors = require('cors')
var app = express()

app.use(cors())

app.get('/products/:id', function (req, res, next) {
  res.json({msg: 'This is CORS-enabled for all origins!'})
})

app.listen(80, function () {
  console.log('CORS-enabled web server listening on port 80')
})

you can also see other method to use cors in [link]https://github.com/expressjs/cors

来源：https://stackoverflow.com/questions/45723370/react-connecting-to-node-cors-preflight-failure

标签

javascript