CORS in Action

Most web developers have encountered the "same-origin" policy enforced by all browsers-pages and applications can't access data from domains other than the one that serves them. This limitation means that complex server-side code is needed in order to share data between different domains.

CORS, Cross-Origin Resource Sharing, is a new web standard that provides a safe method for cross-domain access. CORS in Action introduces Cross-Origin Resource Sharing from both the server and the client perspective. It starts with the basics: making CORS requests and implementing CORS on the server. It then explores key details such as performance, debugging, and security.

API authors learn how CORS opens APIs to a wider range of users. JavaScript developers will find valuable techniques for building rich web apps that can take advantage of APIs hosted anywhere. The techniques described in this book are especially applicable to mobile environments, where browsers are guaranteed to support CORS.