Cfrgtkky

At this point, I feel like I've tried everything I can think of and that has been searched.

The "pure" version of my code is as follows:

Server.js - Express

const express = require('express'),

    path = require('path'),

    bodyParser = require('body-parser'),

    cors = require('cors'),

    mongoose = require('mongoose'),

    config = require('./DB');

    businessRoute = require('../routes/business.route');





mongoose.Promise = global.Promise;

mongoose.connect(config.DB, { useNewUrlParser: true}).then(

    () => { console.log('Database is connected') },

    err => { console.log('Can not connect to the database'+ err) }

);



const app = express();

app.use(bodyParser.json());

app.use(cors());

businessRoute.all('*', cors());

app.use('/business', businessRoute);





let port = process.env.PORT || 4000;



const server = app.listen(function(){

    console.log('Listening on port ' + port);

});

business.route.js - Express, concat.

const express = require('express');

const app = express();

const businessRoutes = express.Router();



// Require Business model in our routes module

let Business = require('../models/Business');





// Defined store route

businessRoutes.route('/add').post(function(req, res) {

    let business = new Business(req.body);

    business.save()

        .then(business => {

            res.status(200).json({'business': 'business added successfully'});

        })

        .catch(err => {

            res.status(400).send("Unable to save to database");

        });

});

business.server.ts - Angular

import { Injectable } from '@angular/core';

import { HttpClient } from '@angular/common/http';



@Injectable({

  providedIn: 'root'

})

export class BusinessService {

  uri = 'http://localhost:4000/business';



  constructor(private http: HttpClient) { }



  addBusiness(person_name, business_name, business_gst_number): void {

    const obj = {

      person_name: person_name,

      business_name: business_name,

      business_gst_number: business_gst_number

    };

    console.log(obj);

    this.http.post(`${this.uri}/add`, obj).subscribe(

      res => console.log('Done')

    );

  }

}

What has been Tried

I've attempted to use the following code, which has been recommended on numerous sites, including SO:

app.use(function(req, res, next) {

  res.setHeader("Access-Control-Allow-Origin", "*");

  res.setHeader('Access-Control-Allow-Methods', 'POST,GET,OPTIONS,PUT,DELETE');

  res.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");

  next();

});

I've attempted to remove the cors module for the code, using the attempted solution as a replacement. I used the code in the express router. I've so used both the module and the code in conjuction in both the server.js and router, as well as (and what is still in the code) businessRoute.all('*', cors());

I'm missing something, I have to be. Any help is appreciated.

As requested, here is the network inspector information from Chrome:

And it did give me an OPTIONS error:

I found the issue, thanks to David. The issue was in:

const server = app.listen(port, function(){

    console.log('Listening on port ' + port);

});

I was missing port in app.listen().

Thank you for everyone who has helped. I'm inclined to delete the question as it does not have to do with CORS at all, but I was given a warning about deleting questions.

A Request For The Community

Editing the question to something like "Why is Express refusing my API requests?" would be a more accurate question, but make the previously posted answers irrelevant. On top of this, Ebin's answer is unique to all the answers I have seen about the CORS issue, and believe it may help others.

For these reasons, I'm leaving it up to the community and how they feel about the question staying, and if they have any suggestions for improving it to make it worth staying.

I had a same error then I used this

app.use((req,res,next)=>{

    res.header("Access-Control-Allow-Origin", "*");

    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");

    if(req.method ==='OPTION'){

        res.header("Access-Control-Allow-Methods", 'GET,POST,PUT,DELETE,PATCH');

        return res.status(200).json({});

    }

    next();

});

then it was worked, try this

Try removing const app = express(); from your business.route.js
and businessRoute.all('*', cors()); from your server.js

I'd use app.use(cors()) before anything else too