site_id = $site_id; } /** * Register hooks for outputting the tracking pixel. * * @return void */ public function add_hooks(): void { add_action('wp_head', [$this, 'output_tracking_script']); add_action('mc4wp_form_subscribed', [$this, 'capture_subscriber_email'], 10, 2); add_action('wp_footer', [$this, 'output_identify_script'], 99); } /** * Output the Mailchimp Site Tracking Pixel SDK script tag. * * @return void */ public function output_tracking_script(): void { if (empty($this->site_id)) { return; } $opts = mc4wp_get_options(); if (empty($opts['tracking_pixel_script_url'])) { return; } wp_enqueue_script('mc4wp-mailchimp-site-tracking-pixel', $opts['tracking_pixel_script_url'], [], MC4WP_VERSION, [ 'strategy' => 'defer', ]); } /** * Capture the subscriber email after a successful form subscription. * * Fires during the mc4wp_form_subscribed action hook. * * @since 4.13.0 * * @param MC4WP_Form $form The submitted form instance. * @param string $email The subscriber's email address. * @return void */ public function capture_subscriber_email($form, string $email): void { $this->identify_email = $email; } /** * Output inline script to identify the subscriber via the Mailchimp pixel SDK. * * Only outputs when a subscriber email was captured during this request. * * @since 4.13.0 * * @return void */ public function output_identify_script(): void { if (empty($this->identify_email) || empty($this->site_id)) { return; } echo '' . "\n"; } /** * Auto-fetch an existing Mailchimp Connected Site that matches the current domain, * or create a new one if none is found. * * @since 4.13.0 * * @param string $api_key API key to use. Defaults to the configured one, pass this explicitly when * the key is about to change since the API service holds the stored key. * * @return array{site_id: string, script_url: string}|false Array with site data on success, false on failure. */ public static function fetch_or_create_connected_site(string $api_key = '') { try { /** @var MC4WP_API_V3 $api */ $api = $api_key === '' ? mc4wp_get_service('api') : new MC4WP_API_V3($api_key); $foreign_id = self::get_foreign_id(); $domain = self::get_site_domain(); $matched_site = null; // First, look the site up by its foreign_id directly. The e-commerce add-on registers a // connected site using the store ID, so this normally hits on the first try. try { $site = $api->get_connected_site($foreign_id); if (isset($site->domain) && self::normalize_domain($site->domain) === $domain) { $matched_site = $site; } else { // The ID belongs to a different domain, so using its script would track the wrong // site. Make the ID unique to this domain in case we end up registering below. $foreign_id .= '-' . substr(md5($domain), 0, 8); } } catch (MC4WP_API_Resource_Not_Found_Exception $e) { // No connected site registered under this ID yet. } // Otherwise, look for an existing site registered under the same domain. if (null === $matched_site) { foreach ($api->get_connected_sites() as $site) { $site_domain = isset($site->domain) ? self::normalize_domain($site->domain) : ''; if ('' !== $site_domain && $site_domain === $domain) { $matched_site = $site; break; } } } // Still nothing, so register a new connected site. Mailchimp rejects a second site for a // domain that is already connected, which is why both lookups above run first. if (null === $matched_site) { $matched_site = $api->add_connected_site([ 'foreign_id' => $foreign_id, 'domain' => $domain, ]); } return [ 'site_id' => sanitize_text_field($matched_site->foreign_id ?? $matched_site->id ?? ''), 'script_url' => esc_url_raw($matched_site->site_script->url ?? ''), ]; } catch (Exception $e) { // Cast the exception to string so Mailchimp's own error detail ends up in the log, // instead of just the HTTP status message. mc4wp_get_service('log')->error(sprintf('Tracking Pixel: error fetching/creating connected site. %s', (string) $e)); return false; } } /** * Returns the domain to register this site under in Mailchimp. * * @return string */ public static function get_site_domain(): string { $home_url = get_home_url(); $domain = self::normalize_domain($home_url); $path = trim((string) wp_parse_url($home_url, PHP_URL_PATH), '/'); // Mailchimp strips the subdirectory part off a domain, which would make every site in a // subdirectory network resolve to the same domain. Turn each path segment into a hostname // label instead, deepest first, so /shop becomes shop.example.com like the e-commerce add-on // registers it and a nested /network/shop becomes shop.network.example.com. if ($path !== '' && is_multisite()) { $labels = array_map([ __CLASS__, 'to_hostname_label' ], array_reverse(explode('/', $path))); $labels = array_filter($labels); if (! empty($labels)) { $domain = implode('.', $labels) . '.' . $domain; } } return $domain; } /** * Turns a single URL path segment into something usable as a hostname label. * * @param string $segment * @return string */ private static function to_hostname_label(string $segment): string { $label = strtolower(rawurldecode($segment)); $label = (string) preg_replace('/[^a-z0-9-]+/', '-', $label); $label = trim((string) preg_replace('/-+/', '-', $label), '-'); return substr($label, 0, 63); } /** * Reduces a URL or domain to the bare hostname Mailchimp stores it as, so that two spellings of * the same site compare equal. Strips the protocol, port, path and the www. prefix. * * @param string $url * @return string */ private static function normalize_domain(string $url): string { $url = trim($url); // Add a scheme-relative prefix so the host is parsed as such for bare domains too. if (strpos($url, '//') === false) { $url = '//' . ltrim($url, '/'); } $host = strtolower((string) wp_parse_url($url, PHP_URL_HOST)); if (strpos($host, 'www.') === 0) { $host = substr($host, 4); } return $host; } /** * Returns a foreign_id to use when registering a new connected site. * Reuses the e-commerce store ID when available so Mailchimp can link them. * * @return string */ private static function get_foreign_id(): string { // Read through the add-on's own getter when available, because it fills in a default store ID // at runtime that is not always written back to the option. if (function_exists('mc4wp_ecommerce_get_settings')) { $ecommerce_settings = mc4wp_ecommerce_get_settings(); } else { $ecommerce_settings = get_option('mc4wp_ecommerce', []); } if (is_array($ecommerce_settings) && ! empty($ecommerce_settings['store_id'])) { return (string) $ecommerce_settings['store_id']; } // sanitize_title() percent-encodes names without any latin characters, so strip anything // that is not safe to use as an identifier. $slug = substr((string) preg_replace('/[^a-z0-9-]/', '', sanitize_title(get_bloginfo('name'))), 0, 32); if ($slug === '') { $slug = 'site'; } return 'mc4wp-' . $slug . '-' . get_current_blog_id(); } }