How to enable cross-origin resource sharing (CORS) in the express.js framework on node.js
node.jsExpressCorsWebserverCross Domainnode.js Problem Overview
I'm trying to build a web server in node.js that will support cross-domain scripting, while still providing static files from a public directory. I'm using the express.js and am not really sure how to allow cross-domain scripting (Access-Control-Allow-Origin: *).
I saw this post, which I did not find helpful.
var express = require('express')
, app = express.createServer();
app.get('/', function (req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Headers", "X-Requested-With");
next();
});
app.configure(function () {
app.use(express.methodOverride());
app.use(express.bodyParser());
app.use(app.router);
});
app.configure('development', function () {
app.use(express.static(__dirname + '/public'));
app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
});
app.configure('production', function () {
var oneYear = 31557600000;
// app.use(express.static(__dirname + '/public', { maxAge: oneYear }));
app.use(express.static(__dirname + '/public'));
app.use(express.errorHandler());
});
app.listen(8888);
console.log('express running at http://localhost:%d', 8888);
node.js Solutions
Solution 1 - node.js
Check out the example from enable-cors.org:
> In your ExpressJS app on node.js, do the following with your routes:
>
> app.all('/', function(req, res, next) {
> res.header("Access-Control-Allow-Origin", "*");
> res.header("Access-Control-Allow-Headers", "X-Requested-With");
> next();
> });
>
> app.get('/', function(req, res, next) {
> // Handle the get for this route
> });
>
> app.post('/', function(req, res, next) {
> // Handle the post for this route
> });
The first call (app.all) should be made before all the other routes in your app (or at least the ones you want to be CORS enabled).
[Edit]
If you want the headers to show up for static files as well, try this (make sure it's before the call to use(express.static()):
app.use(function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Headers", "X-Requested-With");
next();
});
I tested this with your code, and got the headers on assets from the public directory:
var express = require('express')
, app = express.createServer();
app.configure(function () {
app.use(express.methodOverride());
app.use(express.bodyParser());
app.use(function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Headers", "X-Requested-With");
next();
});
app.use(app.router);
});
app.configure('development', function () {
app.use(express.static(__dirname + '/public'));
app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
});
app.configure('production', function () {
app.use(express.static(__dirname + '/public'));
app.use(express.errorHandler());
});
app.listen(8888);
console.log('express running at http://localhost:%d', 8888);
You could, of course, package the function up into a module so you can do something like
// cors.js
module.exports = function() {
return function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Headers", "X-Requested-With");
next();
};
}
// server.js
cors = require('./cors');
app.use(cors());
Solution 2 - node.js
Following @Michelle Tilley solution, apparently it didn't work for me at first. Not sure why, maybe I am using chrome and different version of node. After did some minor tweaks, it is working for me now.
app.all('*', function(req, res, next) {
res.header('Access-Control-Allow-Origin', '*');
res.header('Access-Control-Allow-Methods', 'PUT, GET, POST, DELETE, OPTIONS');
res.header('Access-Control-Allow-Headers', 'Content-Type');
next();
});
In case someone facing similar issue as mine, this might be helpful.
Solution 3 - node.js
Try to this cors npm modules.
var cors = require('cors')
var app = express()
app.use(cors())
This module provides many features to fine tune cors setting such as domain whitelisting, enabling cors for specific apis etc.
Solution 4 - node.js
I use this:
var app = express();
app
.use(function(req, res, next){
res.header('Access-Control-Allow-Origin', '*');
res.header('Access-Control-Allow-Headers', 'X-Requested-With');
next();
})
.options('*', function(req, res, next){
res.end();
})
;
h.readFiles('controllers').forEach(function(file){
require('./controllers/' + file)(app);
})
;
app.listen(port);
console.log('server listening on port ' + port);
this code assumes that your controllers are located in the controllers directory. each file in this directory should be something like this:
module.exports = function(app){
app.get('/', function(req, res, next){
res.end('hi');
});
}
Solution 5 - node.js
Recommend using the cors express module. This allows you to whitelist domains, allow/restrict domains specifically to routes, etc.,
Solution 6 - node.js
You must set Access-Control-Allow-Credentials: true, if you want to use "cookie" via "Credentials"
app.all('*', function(req, res, next) {
res.header('Access-Control-Allow-Origin', '*');
res.header('Access-Control-Allow-Credentials', true);
res.header('Access-Control-Allow-Methods', 'PUT, GET, POST, DELETE, OPTIONS');
res.header('Access-Control-Allow-Headers', 'Content-Type');
next();
});
Solution 7 - node.js
app.use(function(req, res, next) {
var allowedOrigins = [
"http://localhost:4200"
];
var origin = req.headers.origin;
console.log(origin)
console.log(allowedOrigins.indexOf(origin) > -1)
// Website you wish to allow to
if (allowedOrigins.indexOf(origin) > -1) {
res.setHeader("Access-Control-Allow-Origin", origin);
}
// res.setHeader("Access-Control-Allow-Origin", "http://localhost:4200");
// 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,Authorization"
);
// 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();
});
Add this code in your index.js or server.js file and change the allowed origin array according to your requirement.
Solution 8 - node.js
One additional step I needed to take was to switch my URL from http://localhost to http://127.0.0.0