How to tell if someone came to my website from facebook using mobile app

Question

I have the following php code on my server that allows me to tell if user cam to my webpage from facebook:

if ($_SERVER[HTTP_REFERER] == "https://www.facebook.com/") {  do stuff }

So, the problem here is that people are also using facebook on mobile using facebook app, so I don't get the referral link this way.

Is there any way I can tell if someone came to my webpage clicking on a link using facebook app?

Answer 1

I would suggest to use a regex for matching.

http://php.net/manual/en/function.preg-match.php

For example

if (preg_match("/.*\.(facebook|fbdcn)\.com/i", $_SERVER[HTTP_REFERER])) {
    echo "A match was found.";
} else {
    echo "A match was not found.";
}

You can use this site to find a good regex.

https://regex101.com/