HTML5 Data and Services Cookbook

Fetching JSON data with JSONP

JSONP or JSON with padding is a mechanism of making cross-domain requests by taking advantage of the <script> tag. AJAX transport is done by simply setting the src attribute on a script element or adding the element itself if not present. The browser will do an HTTP request to download the URL specified, and that is not subject to the same origin policy, meaning that we can use it to get data from servers that are not under our control. In this recipe, we will create a simple JSONP request, and a simple server to back that up.

Getting ready

We will make a simplified implementation of the server we used in previous examples, so we need Node.js and restify (http://mcavage.github.io/node-restify/) installed either via ...