Question

I need to be able to determine which page the user just came from to determine which links to display, such as breadcrumbs or links to the previous next item. This is basically the HTTP_REFERER functionality in PHP, but I need a way of tracking it across multiple pages. I also need to “support” the back button.

I have noticed that Facebook uses a query/get parameter of “ref” to track the referring page. (They also avoid reloading the entire page, using AJAX instead but I’m don’t have the budget to do that right now.) Also, the site I’m working on needs to be indexed by Google, so this method will also require that I add the canonical link tag.

I’m wondering if the ref/referrer query parameter is the best method or what other options there are?

Answer 1

If you want breadcrumbs, you shouldn’t be using HTTP_REFERER at all. It should be a logical path to get to where they are, no matter where they came from, like User > Albums > AlbumName > Photo, even if they came from a direct link their friend gave them. That said, if you do want to go back a few pages, just store them as a an array in a SESSION variable.

I’m pretty sure Facebook just uses the ref GET variable to collect some statistics on which buttons users are using, since there are multiple ways to get to the same page.

None of this should break the back button, or intefere with your canonical tag.

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From comments: You could use a ?ref=blah tag, or session variables, ($_SESSION['history'][0] = $_SERVER['HTTP_REFERER'] or REQUEST_URI). Use whatever you find easiest. Session variables rely on cookies or passing an ID through the URL, GETs just clutter the URL and might get passed around to friends.