solid-affiliate-snippet-get_user_id_of_affiliate_who_referred_the_current_visitor.php

solid-affiliate-snippet-get_user_id_of_affiliate_who_referred_the_current_visitor.php

<?php
    /**
     * This function will attempt to find the Affiliate who referred the current visitor, 
     * and then return the user id of that affiliate.
     * 
     * Example: 
     * $id = get_user_id_sld (); defaults user id to "1"
     * $id = get_user_id_sld ( 2 ); defaults user id to "2"
     *
     * @param integer $user_id_to_return_if_no_affiliate_found
     * @return integer
     */
    function get_user_id_of_affiliate_who_referred_the_current_visitor($user_id_to_return_if_no_affiliate_found = 1)
    {
        // Test to see if SolidAffiliate is installed
        if (class_exists(\SolidAffiliate\Main::class)) {

            // Check to see if there is an Affiliate for the current page load.
            $affiliate = \SolidAffiliate\Lib\VisitTracking::_affiliate_from_request($_REQUEST);
            if (!is_null($affiliate)) {
                return $affiliate->user_id;
            }

            // If not, Check if cookie is already set.
            $visit_id_or_false = \SolidAffiliate\Lib\VisitTracking::get_cookied_visit_id();
            if ($visit_id_or_false) {
                $visit = \SolidAffiliate\Models\Visit::find($visit_id_or_false);
                if (!is_null($visit)) {
                    $affiliate = \SolidAffiliate\Models\Affiliate::find($visit->affiliate_id);
                    if (!is_null($affiliate)) {
                        return $affiliate->user_id;
                    }
                }
            }
        }
        return $user_id_to_return_if_no_affiliate_found;
    }