I have a small problem with the connection between my Expressjs API and the React client.
Express API -> http://localhost:3001 React -> http://exampleip:3000 (both are on the same windows server)
I added the package CORS and add the following code
const express = require('express');
const cors = require('cors');
const app = express();
app.use(cors());
... other code
app.use('/testdata', async function (req, res) {
const data = await receiveData();
res.send(data);
});
If I fetch the data with the react app on the server where the code is located, I receive the data from the express api without problems.
If I fetch the data with the ip from the react app on my local pc or on a citrix terminal session (windows) on the same network (but not on the same windows server), I receive the following errors.
i prefer to use this code it will help you
// init application
const app = express();
// fix access to back-end
app.use((req, res, next) => {
// Website you wish to allow to connect
res.setHeader("Access-Control-Allow-Origin", process.env.FRONTEND_APP_HOST);
// Request methods you wish to allow
res.setHeader(
"Access-Control-Allow-Methods",
"GET, POST, OPTIONS, PUT, PATCH, DELETE"
);
// Request headers you wish to allow
res.setHeader(
"Access-Control-Allow-Headers",
"X-Requested-With,content-type"
);
// Set to true if you need the website to include cookies in the requests sent
// to the API (e.g. in case you use sessions)
res.setHeader("Access-Control-Allow-Credentials", true);
// Pass to next layer of middleware
next();
});