获取用户访问的链接

Question

Back in the days :) it was possible to find out which links where visited by a user by using the :visited trick.

This worked like a charm, however new browsers (at least the one I've tested it on: Chrome) don't give back the computed style of a link any more.

So I was thinking wouldn't it be possible to create links on a webpage with different colors for visited links, create an image with it using PHP and finally analyzing the image to find out which colors the links have?

If it is possible can you help me in the right direction to do this.

E.g.

How to create the image of an element / entire page

How to analyze the image

Answer 1

Use Javascript to request an image from the homepage of each URL in the background and time the response. It will be almost immediate if the image is cached, which indicates the site has been visited.