Esempi di codice avanzati

Questi esempi dimostrano modelli di integrazione avanzati con Ultimate Multisite.

Motore di prezzi dinamici

Un motore di prezzi basato su regole che applica sconti per volume, fedeltà e stagionali:

class Dynamic_Pricing_Engine {

    public function __construct() {
        add_filter('wu_cart_total', [$this, 'apply_dynamic_pricing'], 20, 2);
    }

    public function apply_dynamic_pricing($total, $cart) {
        $customer = $cart->get_customer();
        $rules = $this->get_pricing_rules();

        foreach ($rules as $rule) {
            if ($this->rule_applies($rule, $cart, $customer)) {
                $total = $this->apply_rule($rule, $total, $cart);
            }
        }

        return $total;
    }

    private function get_pricing_rules() {
        return [
            [
                'type' => 'volume_discount',
                'condition' => ['total_greater_than' => 100],
                'discount' => 0.1
            ],
            [
                'type' => 'loyalty_discount',
                'condition' => ['customer_tenure_months' => 12],
                'discount' => 0.15
            ],
            [
                'type' => 'seasonal_promo',
                'condition' => ['date_range' => ['2024-11-01', '2024-12-31']],
                'discount' => 0.2
            ]
        ];
    }

    private function rule_applies($rule, $cart, $customer) {
        foreach ($rule['condition'] as $condition => $value) {
            switch ($condition) {
                case 'total_greater_than':
                    if ($cart->get_total() <= $value) return false;
                    break;
                case 'customer_tenure_months':
                    if (!$customer || $customer->get_months_active() < $value) return false;
                    break;
                case 'date_range':
                    $now = current_time('Y-m-d');
                    if ($now < $value[0] || $now > $value[1]) return false;
                    break;
            }
        }
        return true;
    }

    private function apply_rule($rule, $total, $cart) {
        $discount_amount = $total * $rule['discount'];

        wu_log_add('pricing', sprintf(
            'Applied %s rule: %.2f discount on total %.2f',
            $rule['type'],
            $discount_amount,
            $total
        ));

        return $total - $discount_amount;
    }
}

new Dynamic_Pricing_Engine();

Provisioning avanzato dei siti

Configura automaticamente nuovi siti con plugin, SSL, CDN, backup e monitoraggio in base alle funzionalità del piano:

class Advanced_Site_Provisioner {

    public function __construct() {
        add_action('wu_site_published', [$this, 'provision_site'], 10, 2);
    }

    public function provision_site($site, $membership) {
        $plan = $membership->get_plan();

        switch_to_blog($site->get_id());

        // Install plugins based on plan
        $this->install_plan_plugins($plan);

        // Configure SSL
        if ($plan->has_feature('ssl')) {
            $this->setup_ssl($site);
        }

        // Setup CDN
        if ($plan->has_feature('cdn')) {
            $this->configure_cdn($site);
        }

        // Configure backups
        if ($plan->has_feature('backups')) {
            $this->setup_automated_backups($site, $plan->get_backup_frequency());
        }

        // Setup monitoring
        $this->setup_site_monitoring($site, $membership->get_customer());

        restore_current_blog();

        $this->send_provisioning_complete_email($site, $membership);
    }

    private function install_plan_plugins($plan) {
        $plugins = $plan->get_included_plugins();

        foreach ($plugins as $plugin_slug) {
            if ($this->plugin_exists($plugin_slug)) {
                activate_plugin($plugin_slug);
                $this->configure_plugin($plugin_slug, $plan);
            }
        }
    }

    private function setup_ssl($site) {
        $ssl_service = new SSL_Provider_API();
        $result = $ssl_service->request_certificate($site->get_domain());

        if ($result->success) {
            $site->add_meta('ssl_certificate_id', $result->certificate_id);
            $site->add_meta('ssl_status', 'active');
        }
    }

    private function configure_cdn($site) {
        $cdn_service = new CDN_Provider_API();

        $zone = $cdn_service->create_zone([
            'name' => $site->get_domain(),
            'type' => 'full'
        ]);

        if ($zone->success) {
            $site->add_meta('cdn_zone_id', $zone->id);
            $this->update_cdn_dns($site, $zone);
        }
    }

    private function setup_automated_backups($site, $frequency) {
        $backup_service = new Backup_Provider_API();

        $schedule = $backup_service->create_schedule([
            'site_id' => $site->get_id(),
            'frequency' => $frequency,
            'retention' => 30
        ]);

        $site->add_meta('backup_schedule_id', $schedule->id);
    }

    private function setup_site_monitoring($site, $customer) {
        $monitoring_service = new Monitoring_API();

        $monitor = $monitoring_service->create_monitor([
            'url' => $site->get_domain(),
            'customer_email' => $customer->get_email(),
            'check_interval' => 300
        ]);

        $site->add_meta('monitoring_id', $monitor->id);
    }
}

new Advanced_Site_Provisioner();

Sistema di limitazioni personalizzato

Traccia e applica limiti di risorse con avvisi di utilizzo:

class Advanced_Limitations {

    public function __construct() {
        add_filter('wu_limitation_plugins_allowed', [$this, 'check_plugin_limit'], 10, 3);
        add_filter('wu_limitation_storage_allowed', [$this, 'check_storage_limit'], 10, 3);
    }

    public function check_plugin_limit($allowed, $site_id, $membership) {
        $plan = $membership->get_plan();
        $max_plugins = $plan->get_limit('max_plugins', 10);

        switch_to_blog($site_id);
        $active_plugins = count(get_option('active_plugins', []));
        restore_current_blog();

        if ($active_plugins >= $max_plugins) {
            $this->send_limit_warning($membership->get_customer(), 'plugins', $max_plugins);
            return false;
        }

        return true;
    }

    public function check_storage_limit($allowed, $site_id, $membership) {
        $plan = $membership->get_plan();
        $max_storage = $plan->get_limit('max_storage_mb', 1000);
        $current_usage = $this->get_site_storage_usage($site_id);

        if ($current_usage >= $max_storage) {
            wu_log_add('limitations', sprintf(
                'Site %d reached storage limit: %dMB/%dMB',
                $site_id,
                $current_usage,
                $max_storage
            ));
            return false;
        }

        if ($current_usage >= ($max_storage * 0.8)) {
            $this->send_storage_warning(
                $membership->get_customer(),
                $current_usage,
                $max_storage
            );
        }

        return true;
    }

    private function get_site_storage_usage($site_id) {
        $upload_dir = wp_upload_dir();
        $size = 0;
        $files = new RecursiveIteratorIterator(
            new RecursiveDirectoryIterator($upload_dir['basedir'])
        );

        foreach ($files as $file) {
            if ($file->isFile()) {
                $size += $file->getSize();
            }
        }

        return round($size / 1024 / 1024, 2);
    }

    private function send_limit_warning($customer, $limit_type, $limit_value) {
        wu_mail_customer($customer, 'limit_warning', [
            'limit_type' => $limit_type,
            'limit_value' => $limit_value,
            'upgrade_url' => wu_get_current_url('upgrade')
        ]);
    }
}

new Advanced_Limitations();

Contatore atomico BerlinDB con increment_item()

Ultimate Multisite v2.6.1 ha aggiunto un metodo increment_item() alla classe BerlinDB Query. Usalo per eseguire incrementi sicuri e atomici su colonne numeriche senza race condition di lettura-modifica-scrittura — utile per contatori, quote di utilizzo e controlli di rate-limiting eseguiti sotto richieste concorrenti.

Firma del metodo

/**
 * Atomically increment a numeric column for a specific item.
 *
 * @param int    $item_id   Primary key of the row to update.
 * @param string $column    Column name to increment (must be numeric).
 * @param int    $amount    Amount to add. Use a negative value to decrement.
 *                          Defaults to 1.
 * @return bool True on success, false on failure or if the column is invalid.
 */
public function increment_item( int $item_id, string $column, int $amount = 1 ): bool;

Utilizzo di base

// Add 1 to the `api_calls` column for membership ID 42.
$memberships = new WP_Ultimo\Database\Memberships\Memberships_Query();
$memberships->increment_item( 42, 'api_calls' );

// Add 5 to a usage counter.
$memberships->increment_item( 42, 'api_calls', 5 );

// Decrement (subtract 1).
$memberships->increment_item( 42, 'api_calls', -1 );

Monitoraggio dell’utilizzo API per membership

Un pattern pratico per applicare limiti di velocità API per membership:

class Membership_API_Limiter {

    /** Maximum API calls allowed per billing cycle. */
    const LIMIT = 500;

    public function __construct() {
        add_filter( 'wu_is_api_enabled', [ $this, 'check_and_count' ], 10, 2 );
    }

    /**
     * Reject the request if the membership is over the limit;
     * otherwise count the call atomically.
     *
     * @param bool   $enabled
     * @param object $context  Object with a get_membership_id() method.
     * @return bool
     */
    public function check_and_count( bool $enabled, $context ): bool {
        if ( ! $enabled ) {
            return false;
        }

        $membership_id = $context->get_membership_id();

        $memberships = new WP_Ultimo\Database\Memberships\Memberships_Query();
        $membership  = $memberships->get_item( $membership_id );

        if ( ! $membership ) {
            return false;
        }

        if ( (int) $membership->api_calls >= self::LIMIT ) {
            return false;  // Over quota — reject.
        }

        // Atomic increment: safe under concurrent requests.
        $memberships->increment_item( $membership_id, 'api_calls' );

        return true;
    }
}

new Membership_API_Limiter();

Perché increment_item() invece di update_item()

Un approccio ingenuo di lettura-modifica-scrittura non è sicuro con richieste concorrenti:

// UNSAFE — race condition between read and write.
$membership = $memberships->get_item( $membership_id );
$new_count  = (int) $membership->api_calls + 1;
$memberships->update_item( $membership_id, [ 'api_calls' => $new_count ] );

Due richieste simultanee possono leggere lo stesso valore ed entrambe riscrivere lo stesso risultato incrementato, perdendo un conteggio. increment_item() delega l’aritmetica al motore del database con una singola istruzione UPDATE ... SET column = column + ?, rendendo l’operazione intrinsecamente atomica.