There are web applications out there on the interwebs that are designed to take a website’s url, load the page, and then dress that page up with additional functionality. When trying to develop one of these on your own, you will quickly learn that there are several ways of displaying a page within another page, but only two of them are really popular: 1. displaying the page in an iFrame, and 2. rendering the contents of that page as markup in an html5 canvas.
Both methods are troublesome at first due to the fact that its hard to get the markup without having access to it from the parent DOM. So the most popular solution is to build a proxy to take in the data and return it to you before displaying. Let’s dig deeper into the idea of proxying data.