CORS npm for Express.js using Connect.js middleware

Connect.js provides middleware for handling requests in Express.js.

You can use node package manager (npm) to install a package that enables CORS in Express.js with Connect.js:

npm install cors

The package offers flexible options, which should be familiar to the CORS specification, including using credentials and preflight. It provides dynamic ways of validating an origin domain using a function or a regular expression, and handler functions to process preflight.

Configuration options for CORS npm

The following are the options for CORS npm:

origin: Configures the Access-Control-Allow-Origin CORS header with a string containing the full URL and protocol making the request, for example http://localdomain.com.

Possible values for origin:

• The default value TRUE uses req.header('Origin') to determine the origin and CORS is enabled

• When set to FALSE, CORS is disabled

• It can be set to a function with the request origin as the first parameter and a callback...