Personalized promo codes for user

This case ties a promo code to a specific user, blocking use in any other case.

Option 1

Very simple! Create a plugin on event mspcOnBeforeSetCoupon with this code:

switch ($modx->event->name) {
  case 'mspcOnBeforeSetCoupon':
    // Coupon is personalized if description contains "user: [[+username]]", otherwise no checks
    if (!preg_match('/^user\: /i', $coupon['description'])) {
      break;
    }
    $username = preg_replace('/^user\: (.*)$/ui', '$1', $coupon['description']);

    // If coupon description contains user's username, apply the promo code
    if (is_object($modx->user) && $modx->user->get('username') == $username) {
      break;
    }

    // Return coupon application error
    $modx->event->output('Promo code "' . $coupon['code'] . '" is not your personalized code!');
    break;
}

Important

When creating the promo code, put user: [[+username]] in the description, where [[+username]] is the login of the user who owns the promo code.

Option 2

You can skip the name check in the description and create coupons with the user's username as the code. So the promo code equals the username of the coupon owner. Code for this approach:

switch ($modx->event->name) {
  case 'mspcOnBeforeSetCoupon':
    // Personalized promo code when coupon description is "user"
    if ($coupon['description'] != 'user') {
      break;
    }

    // If coupon code equals user's username, apply it
    if (is_object($modx->user) && $modx->user->get('username') == $coupon['code']) {
      break;
    }

    // Return coupon application error
    $modx->event->output('Promo code "' . $coupon['code'] . '" is not your personalized code!');
    break;
}

Important

When creating the promo code, write user in the description so the script knows the coupon is personalized.