Perform extra validation after a Student signs into Moodle - moodle

Question

I am hoping someone can point me in the right direction. We host a University Moodle site and we are looking for a way in which we can perform extra validation on a Student whenever they login. I will give a scenario.
We have an endpoint with a list of email addresses of students allowed to use the system, for example a list of Students who are fully paid up on tuition. Therefore, we are looking for a way to hook into the login process, perform this check and the allow the student to continue or redirect back to the login page with an error.
I would appreciate any advice on how we can achieve this. Thank you.

Answer 1

I found a solution to my problem. I ended up creating a custom Authentication plugin using the guidelines from https://docs.moodle.org/dev/Authentication_plugins. With that knowledge, I used the copied the folder in the Moodle installation path auth/none and used that as a shell for my new plugin. I went ahead and customized the plugin names to what I needed. Once that was done and once the plugin was installed and enabled from the Administrator Dashboard, I had something like this in my auth.php file:
// Required for all auth plugins
public function user_login($username, $password)
{
return false;
}
// Hooks in immediately after the User submits the login form
public function loginpage_hook()
{
$username = $_REQUEST['username'] ?? '';
/** CODE CHECKING IF USERNAME IS ALLOWED TO ACCESS MOODLE **/
/** FOR EXAMPLE CHECK IF USER PAID FEES **/
$userHasPaidFees = api_checks_if_user_paid_fees($username);
if ($userHasPaidFees ) {
// Returning true here proceeds with the
// normal Username/Password login combination
return true;
}
// If not, redirect them back to Login
// Or any other page and notify
redirect(
new moodle_url('/login/index.php'),
'Message telling user why they were not able to sign in',
null,
\core\output\notification::NOTIFY_ERROR
);
}
Thanks and I hope someone finds this useful.