Install
koa-cors
CORS middleware for Koa
Inspired by the great node-cors module.
Installation (via npm)
$ npm install koa-cors
Usage
var koa = require('koa');
var route = require('koa-route');
var cors = require('koa-cors');
var app = koa();
app.use(cors());
app.use(route.get('/', function() {
this.body = { msg: 'Hello World!' };
}));
app.listen(3000);
Options
origin
Configures the Access-Control-Allow-Origin CORS header. Expects a string
(ex: http://example.com). Set to true to reflect the
request origin, as defined
by req.header('Origin'). Set to false to disable CORS. Can also be set to a
function, which takes the request as the first parameter.
expose
Configures the Access-Control-Expose-Headers CORS header. Expects a
comma-delimited string (ex: 'WWW-Authenticate,Server-Authorization') or an array
(ex: ['WWW-Authenticate', 'Server-Authorization]). Set this to pass the
header, otherwise it is omitted.
maxAge
Configures the Access-Control-Max-Age CORS header. Set to an integer to pass
the header, otherwise it is omitted.
credentials
Configures the Access-Control-Allow-Credentials CORS header. Set to true
to pass the header, otherwise it is omitted.
methods
Configures the Access-Control-Allow-Methods CORS header. Expects a
comma-delimited string (ex: 'GET,PUT,POST') or an array (ex: ['GET', 'PUT', 'POST']).
headers
Configures the Access-Control-Allow-Headers CORS header. Expects a
comma-delimited string (ex: 'Content-Type,Authorization') or an array (ex:
['Content-Type', 'Authorization]). If not specified, defaults to reflecting
the headers specified in the request's Access-Control-Request-Headers
header.
For details on the effect of each CORS header,
read this article on HTML5 Rocks.
