I'm integrating PayPal Buy Now button in a website, currently in a Sandbox using this method. I have implemented official IPN processing mechanism from PayPal sample source on GitHub.
It is redirecting to my specified page but POST data is empty. I'm using file_get_contents("php://input") for it.
$raw_post_data = file_get_contents('php://input');
$raw_post_array = explode('&', $raw_post_data);
I changed it to $_POST as well but both were empty.
How do I solve this?
The information you have provided is too little to help you.
However, you can try using a ready to use class like https://github.com/Quixotix/PHP-PayPal-IPN
Here is a tutorial to integrate it http://www.micahcarrick.com/paypal-ipn-with-php.html