Affiliate Tracking on initial subscription in MemberPress & Affiliate Royale

mp_ar_paid_signup_notification.php

<?php

add_action('mepr-txn-status-complete', 'mapsn_notification');

function mapsn_notification($txn) {
  global $wpdb;
  $mepr_db = new MeprDb();

  $usr = $txn->user();
  $usr_id = $usr->ID;

  $txn_count = $wpdb->get_var(
    $wpdb->prepare(
      "SELECT COUNT(*) FROM {$mepr_db->transactions} WHERE user_id=%d AND type=%s AND status=%s",
      $usr_id, MeprTransaction::$payment_str, MeprTransaction::$complete_str
    )
  );

  if( $txn_count <= 1 ) {
    $wafp_usr = new WafpUser($usr_id);
    $ref_id = $wafp_usr->get_referrer();

    if(!empty($ref_id) and is_numeric($ref_id)) {
      // $ref_id is the user id of the affiliate
      // $usr_id is the user id of the customer
    }
  }
}