Express JS: No 'Access-Control-Allow-Origin' header is present on the requested resource

Question

I have an API running on a server and a front-end client connecting to it to retrieve data. I did some research on the cross domain problem and has it working. However I\'ve

Answer 1

You can also use cors npm for the same.

**npm i cors**

const cors = require('cors')

var corsOptions = {
  origin: '*',
  optionsSuccessStatus: 200 // some legacy browsers (IE11, various SmartTVs) choke on 204 
}
app.use(cors(corsOptions));

var routes = require('./api/routes/route'); //importing route
routes(app); //register the route

Answer 2

Instead of setting the request headers to your express route, Can you try setting it to express instance itself like this,

var express = require('express');
var app = express();
var Assessment = require('../app/models/assessment');

app.use(function(req, res, next) {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
  next();
});

app.post('/api/status', function (req, res, next) {
    // your code goes here
});

module.exports = app;

Hope this helps!

Answer 3

Check your server.js file. It should look like the example below:

const express = require('express');
const bodyParser = require('body-parser');
var cors = require('cors');
const mongoose = require('mongoose');
// create express app
const app = express();

// parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ extended: true }))

// parse application/json
app.use(bodyParser.json())

app.use(cors());