PHP FollowUpEmails::is_woocommerce_installed示例

 public static function mail($to, $subject, $message, $headers = '', $attachments = '')
 {
     if (FollowUpEmails::is_woocommerce_installed()) {
         global $woocommerce;
         // send the email
         $disable_wrap = get_option('fue_disable_wrapping', 0);
         $mailer = $woocommerce->mailer();
         if (!$disable_wrap) {
             $message = $mailer->wrap_message($subject, $message);
         }
         $mailer->send($to, $subject, $message, $headers, $attachments);
     } else {
         add_filter('wp_mail_content_type', 'FUE::set_html_content_type');
         wp_mail($to, $subject, $message, $headers, $attachments);
         remove_filter('wp_mail_content_type', 'FUE::set_html_content_type');
     }
 }