Testing the connection between my local React frontend and Node.JS server

Question

I've created a node.JSExpress server whose role is to send JSON to my frontend using the API. I completed the backend and put it on an AWS server. Now I just want to work on React frontend. I start react on localhost:3000 and make a request to the AWS server, but I get a CORS error telling me that localhost:3000 does not have permission to send requests to that server. Get "http://www.myawsse" from source "http://localhost:3000"

P粉077701708 · Answer

Here are the combined steps to resolve CORS errors and enable communication between the React frontend and the AWS server

`Configuring CORS on your AWS server`

First, you need to configure your server to include the appropriate CORS headers in the response . You need to add the "Access-Control-Allow-Origin" header with the value "http://localhost:3000" to allow requests from your React application.

`Specific method to configure CORS`

The exact method of configuring CORS depends on the server technology you are using (e.g. Express, Apache, Nginx). For example, if you use Express, you can use the cors middleware. Here is an example of how to configure CORS using Express:

const express = require('express');
const cors = require('cors');

const app = express();

app.use(cors({ origin: 'http://localhost:3000' }));

// Rest of your server code...

app.listen(4000, () => {
  console.log('Server running on port 4000');
});

`Restart your AWS server`

After configuring CORS, restart the AWS server to apply the changes.