CORS No Access-Control-Allow-Origin

Question

Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

I'm having a hard time solving CORS error lately and I admit that I'm still learning express and server programming. I'm trying to submit a payload to the database but once I'm requesting on the server, chrome returns the error on the title. I've tried several fixes like adding wildcard on the origin of corsOptions, following the guide of cors https://github.com/expressjs/cors. I even added a require cors on one of my route file but still not working.

Here's the current code that I'm working with

index.js

const corsOptions ={
    origin:'http://localhost', 
    credentials:true,            //access-control-allow-credentials:true
    optionSuccessStatus:200,
}

const app = express();

app.use(cors(corsOptions));
app.use(express.json());
const { StatusCodes, ReasonPhrases } = require("http-status-codes");

app.use(cors());
const server = http.createServer(function (req, res) {
    console.log('A request was made: ' + req.url);
    res.writeHead(200, {'Content-Type': 'text-plain'});
    res.end('Response ended'); // ends the response
});
server.listen(3000, 'localhost');

app.get("/", (req, res) => {
    res.status(StatusCodes.OK).json({
      title: "Waiting for request...",
      status: StatusCodes.OK,
    });
  });

const ups = require('./routes/ups.js');
app.use("/ups", cors(), ups);

  app.all("*", (req, res, next) => {
    res.status(StatusCodes.METHOD_NOT_ALLOWED).json({
      status: StatusCodes.METHOD_NOT_ALLOWED,
      title: ReasonPhrases.METHOD_NOT_ALLOWED,
    });
    next();
  });

ups.js

const cors = require('cors');
const { StatusCodes, ReasonPhrases } = require("http-status-codes");

module.exports = () => {
    router.post("/ups", cors(),  (req, res) => {
      if(
        req.body == null ||
        req.body.id == null ||
        req.body.available == null
      ) {
        console.log("error");
      }

      var id = req.body.id;
      var av = req.body.available;

      //Perform Query Ops
      var sql = "UPDATE `pc_status` SET available = " + av + " WHERE `id` = " + id + "";
      db.query(sql, function(err, result) {
      if (err) throw err;
        console.log('record inserted');
        console.log(req.body.id);
        console.log(req.body.available);
        //result.redirect(201 ,'/');
      });

    });
    return router;
};

Does this answer your question? [No 'Access-Control-Allow-Origin' header is present on the requested resource—when trying to get data from a REST API](https://stackoverflow.com/questions/43871637/no-access-control-allow-origin-header-is-present-on-the-requested-resource-whe) — Andy Ray, May 27 '23 at 04:13

score 0 · Answer 1 · answered May 27 '23 at 06:29

here is few updates on your code:

index.js:

const corsOptions ={
    origin:'http://localhost:3000' // mention the port of front-end, 
    credentials:true,            //access-control-allow-credentials:true
    optionSuccessStatus:200,
}

const app = express();

app.use(cors(corsOptions));
app.use(express.json());
const { StatusCodes, ReasonPhrases } = require("http-status-codes");

app.use(cors()); 
const server = http.createServer(function (req, res) {
    console.log('A request was made: ' + req.url);
    res.writeHead(200, {'Content-Type': 'text-plain'});
    res.end('Response ended'); // ends the response
});
server.listen(3000, 'localhost');

app.get("/", (req, res) => {
    res.status(StatusCodes.OK).json({
      title: "Waiting for request...",
      status: StatusCodes.OK,
    });
  });

const ups = require('./routes/ups.js');
app.use("/ups", c̶o̶r̶s̶(̶)̶, ups); // when you provide cors on .use(), you don't need to specify on each routes!

  app.all("*", (req, res, next) => {
    res.status(StatusCodes.METHOD_NOT_ALLOWED).json({
      status: StatusCodes.METHOD_NOT_ALLOWED,
      title: ReasonPhrases.METHOD_NOT_ALLOWED,
    });
    next();
  });

ups.js :

const cors = require('cors');
const { StatusCodes, ReasonPhrases } = require("http-status-codes");

module.exports = () => {
    router.post("/ups", cors(),  (req, res) => {
      if(
        req.body == null ||
        req.body.id == null ||
        req.body.available == null
      ) {
        console.log("error");
      }

      var id = req.body.id;
      var av = req.body.available;

      //Perform Query Ops
      var sql = "UPDATE `pc_status` SET available = " + av + " WHERE `id` = " + id + "";
      db.query(sql, function(err, result) {
      if (err) throw err;
        console.log('record inserted');
        console.log(req.body.id);
        console.log(req.body.available);
        //result.redirect(201 ,'/');
      });

    });
    return router;
};

hope you found solution, if still not fixed let me know..

CORS No Access-Control-Allow-Origin

1 Answers1