Overwrite the Affiliate Cookie in Ultimate Affiliate Pro

In Ultimate Affiliate Pro, when a user clicks on an affiliate link, a cookie (such as uap_referral) is set to track the affiliate. If the same user clicks on a different affiliate link later, you might want to overwrite the existing cookie to credit the new affiliate.

Here’s how you can handle this scenario:

Steps to Overwrite the Affiliate Cookie

1. Check if the Cookie Exists:
   • Before setting a new cookie, check if the current uap_referral cookie exists.
2. Overwrite the Cookie if a New Affiliate Link is Used:
   • If the cookie exists and a different affiliate link is used, overwrite the current cookie with the new affiliate ID.
3. Code to Overwrite the Cookie:

You can hook into WordPress’s init action to check for the affiliate link, and then overwrite the existing affiliate cookie if necessary.

function overwrite_affiliate_cookie() {
    // Check if an affiliate ID is present in the URL (e.g., ?ref=affiliate_id)
    if (isset($_GET['ref'])) {
        $new_affiliate_id = sanitize_text_field($_GET['ref']);

        // Check if the current cookie exists
        if (isset($_COOKIE['uap_referral'])) {
            // Get the current cookie value
            $current_affiliate_data = unserialize(stripslashes($_COOKIE['uap_referral']));

            // Compare the current affiliate ID with the new one
            if ($current_affiliate_data['affiliate_id'] != $new_affiliate_id) {
                // Overwrite the cookie with the new affiliate ID
                $new_affiliate_data = array(
                    'affiliate_id' => $new_affiliate_id,
                    'campaign' => '', // Add campaign if needed
                    'referral_hash' => md5(uniqid($new_affiliate_id, true)), // Generate a new referral hash
                    'visit_id' => $current_affiliate_data['visit_id'] + 1, // Increment visit ID (optional)
                    'timestamp' => time(),
                    'site_referer' => isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : '',
                );

                // Serialize the new data
                $new_affiliate_data_serialized = serialize($new_affiliate_data);

                // Set the cookie with the new affiliate data
                setcookie('uap_referral', $new_affiliate_data_serialized, time() + (86400 * 30), '/'); // 30 days expiry

                // Optionally, log or debug
                // error_log('Affiliate cookie overwritten: ' . print_r($new_affiliate_data, true));
            }
        } else {
            // Set a new cookie if it doesn't exist
            $affiliate_data = array(
                'affiliate_id' => $new_affiliate_id,
                'campaign' => '', // Add campaign if needed
                'referral_hash' => md5(uniqid($new_affiliate_id, true)),
                'visit_id' => 1, // Start with visit ID 1
                'timestamp' => time(),
                'site_referer' => isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : '',
            );

            // Serialize and set the cookie
            $affiliate_data_serialized = serialize($affiliate_data);
            setcookie('uap_referral', $affiliate_data_serialized, time() + (86400 * 30), '/'); // 30 days expiry
        }
    }
}
add_action('init', 'overwrite_affiliate_cookie', 2);

Explanation of Code:

1. Check for ref Query Parameter:
   • The code looks for the affiliate ID in the URL parameter (e.g., ?ref=123).
2. Retrieve Current Cookie Value:
   • If the uap_referral cookie is already set, it is retrieved and unserialized into an array.
3. Compare Affiliate IDs:
   • If the current affiliate ID stored in the cookie is different from the new one (from the ref query parameter), the cookie is overwritten with the new affiliate data.
4. Set a New Cookie if Not Present:
   • If the cookie does not exist, it is created with the new affiliate ID.
5. Serialize and Set the Cookie:
   • The cookie data is serialized and saved, with an expiration time of 30 days (86400 * 30).
6. Unique Referral Hash:
   • A new referral_hash is generated each time an affiliate ID is stored.
7. Hook it early in the init, in my example it is on level 2 priority.

Important Notes:

• Sanitization: Always sanitize the input from the URL using sanitize_text_field() to avoid security vulnerabilities.
• Cookie Expiration: The cookie is set to expire after 30 days (time() + (86400 * 30)), but you can adjust this based on your requirements.
• Referrals: If your campaign involves additional tracking parameters (like campaign), you can add that to the cookie as well.
• Testing: Ensure that you test this code thoroughly in a development environment to confirm that the cookie is properly overwritten when a different affiliate link is clicked.

This method ensures that the uap_referral cookie is updated with the latest affiliate link when the user clicks on a new one, while respecting the rules of your affiliate program.