I'm now writing a program (called A.app) which will post some data to a php code under /wp-admin (call B.php). I put
require_once('admin.php'); at the first line in B.php which forces to auth user first then processes the data after login.
Here is my problem, after redirect by wp-login.php, the original post data ($_POST) by A.app can't be access anymore. Could someone here kindly help me on this? Thank you. :)