CommentNotifiable.php

<?php

namespace SilverStripe\CommentNotifications\Extensions;

use SilverStripe\Comments\Model\Comment;
use SilverStripe\ORM\DataExtension;
use SilverStripe\Control\Email\Email;
use SilverStripe\Security\Member;
use Traversable;

class CommentNotifiable extends DataExtension
{

    /**
     * Default subject line if the owner doesn't override it
     *
     * @config
     * @var string
     */
    private static $default_notification_subject = 'A new comment has been posted';

    /**
     * Default sender
     *
     * @config
     * @var string
     */
    private static $default_notification_sender = 'noreply@{host}';

    /**
     * Default template to use for comment notifications
     *
     * @config
     * @var string
     */
    private static $default_notification_template = 'SilverStripe\\CommentNotifications\\CommentEmail';

    /**
     * Return the list of members or emails to send comment notifications to
     *
     * @param Comment $comment
     * @return array|Traversable
     */
    public function notificationRecipients($comment)
    {
        $list = [];

        if ($adminEmail = Email::config()->admin_email) {
            $list[] = $adminEmail;
        }

        $this->owner->invokeWithExtensions('updateNotificationRecipients', $list, $comment);

        return $list;
    }

    /**
     * Gets the email subject line for comment notifications
     *
     * @param Comment $comment Comment
     * @param Member|string $recipient
     * @return string
     */
    public function notificationSubject($comment, $recipient)
    {
        $subject = $this->owner->config()->default_notification_subject;

        $this->owner->invokeWithExtensions('updateNotificationSubject', $subject, $comment, $recipient);

        return $subject;
    }

    /**
     * Get the sender email address to use for email notifications
     *
     * @param Comment $comment
     * @param Member|string $recipient
     * @return string
     */
    public function notificationSender($comment, $recipient)
    {
        $sender = $this->owner->config()->default_notification_sender;

        // Do hostname substitution
        $host = isset($_SERVER['HTTP_HOST'])
            ? preg_replace('/^www\./i', '', $_SERVER['HTTP_HOST'])
            : 'localhost';
        $sender = preg_replace('/{host}/', $host ?? '', $sender ?? '');

        $this->owner->invokeWithExtensions('updateNotificationSender', $sender, $comment, $recipient);

        return $sender;
    }

    /**
     * Determine the template to use for this email
     *
     * @param Comment $comment
     * @param Member|string $recipient
     * @return string Template name (excluding .ss extension)
     */
    public function notificationTemplate($comment, $recipient)
    {
        $template = $this->owner->config()->default_notification_template;

        $this->owner->invokeWithExtensions('updateNotificationTemplate', $template, $comment, $recipient);

        return $template;
    }

    /**
     * Update the notification email
     *
     * @param Email $email
     * @param Comment $comment
     * @param Member|string $recipient
     */
    public function updateCommentNotification($email, $comment, $recipient)
    {
        //
    }
}