Allowing Multiple Cors In Node Express - node.js

Question

I'm trying to allow multiple cors with node in my express api, I've been able to get it to work but am currently facing two issues.
I can't connect to my api using postman because I checked and it turns out the origin sent from postman is undefined.
I have a mobile app which also communicate with the server, the issue is after I allowed multiple specific origin, the app also can't communicate with the server.
How do I solve this issue, because I can't leave my api server open to allow communication from every origin.

Answer 1

Have you tried with Cors for nodejs
Add the dependency:
$ npm install cors --save
And then add cors to your app.js
var cors = require('cors')
var app = express()
app.use(cors())

Answer 2

On production try this instead of * on Access-Control-Allow-Origin header, For development allow any source will not be a problem (depend on your scenario)
app.use(function(req, res, next) {
res.header("Access-Control-Allow-Origin", "yourdomain.com");
res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
next();
});

Answer 3

app.use(function(req, res, next) {
res.setHeader('Access-Control-Allow-Origin', '*');
res.setHeader('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS');
res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
res.setHeader('Access-Control-Expose-Headers','Content-Type,expire');
next();
});
Try this one in your server. If you want to pass extra header parameter you need to add those variable in res.setHeader('Access-Control-Allow-Headers', 'Content-Type , token'); but remember don't user '-' in the variable name.