AffiliateWP – Force Query String Format for Affiliate Deep Links

/**

 * Fix: Force query string format for all affiliate referral URLs.

 *

 * Part 1: Updates the in-memory settings so the portal URL generator

 *         and affwp_get_affiliate_referral_url() both produce ?ref=value

 *         format instead of /ref/value/ format. No database change.

 *

 * Part 2: Converts any incoming pretty deep link (/page/ref/value/) to

 *         query string format (/page/?ref=value) via 301 redirect.

 *         Fixes redirect loops for links already in the wild.

 *         Skips root-level pretty URLs (/?ref=value works fine).

 */

// Part 1: Force query string format in URL generation.

add_action( 'plugins_loaded', function() {

    affiliate_wp()->settings->set( array( 'referral_pretty_urls' => false ) );

}, 20 ); // Priority 20 runs after AffiliateWP initializes at priority 10.

// Part 2: Redirect incoming pretty deep links to query string format.

add_action( 'init', function() {

    if ( is_admin() ) {

        return;

    }

    $referral_var = affiliate_wp()->tracking->get_referral_var();

    $request_uri  = isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '';

    // Match URLs like /some/path/ref/username/ or /some/path/ref/username/?foo=bar

    $pattern = '#^(/[^?]+)/' . preg_quote( $referral_var, '#' ) . '/([^/?]+)/?(\?.*)?$#';

    if ( ! preg_match( $pattern, $request_uri, $matches ) ) {

        return;

    }

    $path         = trailingslashit( $matches[1] );

    $affiliate    = sanitize_text_field( $matches[2] );

    $query_string = ! empty( $matches[3] ) ? ltrim( $matches[3], '?' ) : '';

    // Skip root-level pretty URLs e.g. domain.com/ref/username/ -- those work fine.

    if ( '/' === $path ) {

        return;

    }

    // Build the query string version of the URL.

    $redirect = add_query_arg( $referral_var, $affiliate, home_url( $path ) );

    if ( $query_string ) {

        $redirect .= '&' . $query_string;

    }

    // Use header() directly to bypass AffiliateWP's wp_redirect filter,

    // which would re-append /ref/username/ and recreate the loop.

    header( 'Location: ' . esc_url_raw( $redirect ), true, 301 );

    exit;

}, 1 ); // Priority 1 runs before AffiliateWP's fallback tracking at priority -9999... 

        // actually at priority 1 this fires before AffiliateWP's template_redirect,

        // but we're on 'init' so it's earlier in the request lifecycle entirely.