Helper de notificaciones para wordpress

NotificationHelper.php

<?php  
/**
 * notificationHelper.php
 *
 * @author Mxrck
 * @version 1.0
 *
 * Una sencilla clase creada para facilitar el envío de notificaciones 
 * en el backend de Wordpress, ya sea para temas o plugins, con la 
 * posibilidad de enviar emails.
 *
 * http://marcomaldonado.com
 */
namespace mxrck\tools;

class NotificationHelper {

    private static $instance = null;
    private $email = false;
    private $sendEmails = true;
    private $notifications = array();
    public static $MSG_ERROR    = 'notice-error';
    public static $MSG_WARNING  = 'notice-warning';
    public static $MSG_SUCCESS  = 'notice-success';
    public static $MSG_INFO     = 'notice-info';

    private function __construct($config)
    {
        $this->init($config);
    }

    private function init($config = array())
    {
        if (is_array($config)) {
            foreach ($config as $key => $value) {
                $this->$key = $value;
            }
        }
        $this->hooks();

        return $this;
    }

    public static function getInstance($config = array())
    {
        if (self::$instance == null) {
            self::$instance = new NotificationHelper($config);
        }
        return self::$instance;
    }

    private function hooks()
    {
        add_action( 'admin_notices', array($this, 'showNotifications') );

        return $this;
    }

    public function setEmail($email)
    {
        if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
            $this->email = $email;
        }

        return $this;
    }

    public function setSendEmails($send)
    {
        $this->sendEmails = is_bool($send) ? $send : false;

        return $this;
    }

    public function showNotifications()
    {
        foreach($this->notifications as $notification) {
            printf(
                '<div class="notice %1$s"><p>%2$s</p></div>',
                $notification->type,
                $notification->message
            );
        }
        $this->forceSendEmails();

        return $this;
    }

    public function forceSendEmails()
    {
        foreach($this->notifications as $notification) {
            $this->sendEmail($notification);
        }

        return $this;
    }

    private function sendEmail($notification)
    {
        if (
            $this->sendEmails !== false      &&
            $this->email !== false          &&
            $notification                   &&
            isset($notification->email)     &&
            $notification->email === true   &&
            isset($notification->message)   &&
            isset($notification->type)      &&
            is_array($notification->emailOptions)
        ) {
            $body = empty($notification->emailOptions['body']) ? $notification->message : $notification->emailOptions['body'];
            wp_mail(
                $this->email,
                $notification->emailOptions['subject'],
                $body,
                $notification->emailOptions['headers'],
                $notification->emailOptions['attachments']
            );
        }

        return $this;
    }

    private function prepareEmailOptions($emailOptions = array(), $type = '')
    {
        $email = array(
            'headers'       => array(),
            'attachments'   => array(),
            'subject'       => __('Ésta es una notificación de tu sistema en Wordpress', 'notifications'),
            'body'          => ''
        );
        $email['headers']       = isset($emailOptions['headers']) ? $emailOptions['headers'] : $email['headers'];
        $email['attachments']   = isset($emailOptions['attachments']) ? $emailOptions['attachments'] : $email['attachments'];
        $email['subject']       = isset($emailOptions['subject']) ? $emailOptions['subject'] : $email['subject'];
        $email['body']          = isset($emailOptions['body']) ? $emailOptions['body'] : $email['body'];
        $email['subject'] = $this->prependSubject($type).$email['subject'];

        return $email;
    }

    private function prependSubject($type)
    {
        $preppend = '';
        switch ($type) {
            case NotificationHelper::$MSG_INFO:
                $preppend = __('[INFORMACIÓN]', 'notifications').' ';
                break;
            case NotificationHelper::$MSG_ERROR:
                $preppend = __('[ERROR]', 'notifications').' ';
                break;
            case NotificationHelper::$MSG_WARNING:
                $preppend = __('[ATENCIÓN]', 'notifications').' ';
                break;
            case NotificationHelper::$MSG_SUCCESS:
                $preppend = __('[ÉXITO]', 'notifications').' ';
                break;
        }
        return $preppend;
    }

    public function addNotification($message, $type = 'notice-info', $email = false, $emailOptions = array())
    {
        if (
            $type != NotificationHelper::$MSG_ERROR     &&
            $type != NotificationHelper::$MSG_WARNING   &&
            $type != NotificationHelper::$MSG_SUCCESS   &&
            $type != NotificationHelper::$MSG_INFO
        ) {
            $type = 'notice-info';
        }
        $notification = new \stdClass();
        $notification->message = $message;
        $notification->type = $type;
        $notification->email = is_bool($email) ? $email : false;
        $notification->emailOptions = $this->prepareEmailOptions($emailOptions, $type);
        array_push(
            $this->notifications,
            $notification
        );

        return $this;
    }

}

<?php  
/*
...
*/

// Cargando librerías
require_once 'autoload.php'; // Carga el archivo notificationHelper.php

use \mxrck\tools\NotificationHelper;

add_action('init', 'initPlugin');

function initPlugin() {  
$notificator = NotificationHelper::getInstance();
$notificator->setEmail('testing@email.com');
$notificator
    ->addNotification('Mensaje de información', NotificationHelper::$MSG_INFO)
    ->addNotification('Mensaje de error', NotificationHelper::$MSG_ERROR)
    ->addNotification('Mensaje de éxtio', NotificationHelper::$MSG_SUCCESS)
    ->addNotification('Mensaje de precaución', NotificationHelper::$MSG_WARNING)
    ->addNotification('Mensaje de error con envío de email', NotificationHelper::$MSG_ERROR, true); // Envía un email
}