Peeking at the Browser's History

Web Developer’s Quiz: Your website needs to somehow know what are the other websites a user had already visited. How do you do it? How do you get the information from a browser history?

Kevin Burton pulled it off with a neat trick. When the new features of his Tailrank were released. I must’ve been sleeping or busy, anyways, didn’t check out the improvements in Tailrank till now.

Under "import", a user usually uploads his OPML file (which I’d previously talked about), input some URLs, etc. In his attempt to make Tailrank’s import applicable to more layman users, Kevin has a new "Auto Configure" button. Click on it, and a list of popular sites (that you  have visited) are found and is ready for import. Damn, how did it know!

I did some view-source hunting and found document.defaultView.getComputedStyle and element.currentStyle. Explain: Given that your browser will style visited links differently from link not yet visited, Kevin merely printed a bunch of hidden links and used a javascript to pick out those you have visited! Woot! I can sure find some use for that… hmm.. can’t think of any now, but I’m sure there’re uses!

That said, I would’ve preferred if Tailrank actually gave me the option to uncheck some of them from my list (especially since removal of feeds isn’t implemented yet)