Notifications represent a message ready to be sent to a recipient.

Notifications

A typical example of a notification:

$notification = (new \Symfony\Component\Notifier\Notification\Notification())
  ->subject('Subject!')
  ->contents('Contents!');

SMS messages

For SMS, the subject is used as the contents of the message. contents are not used.

The Notification class may be subclassed with your own functionality. There is no generic interface which can be used to start from scratch.

Messages

To achieve more control over the specific message generated by a notification, subclass Notification and implement a channel specific interface such as \Symfony\Component\Notifier\Notification\SmsNotificationInterface or \Symfony\Component\Notifier\Notification\EmailNotificationInterface:

This example produces an email message:

namespace Drupal\my_module;

use Symfony\Component\Notifier\Notification\EmailNotificationInterface;
use Symfony\Component\Notifier\Notification\Notification;
use Symfony\Component\Notifier\Message\EmailMessage;

final class MyNotification extends Notification implements EmailNotificationInterface {
  public function asEmailMessage(EmailRecipientInterface $recipient, ?string $transport = null): ?EmailMessage {
    // Construct the email message:
    return new EmailMessage();
  }
}

Resources

Read more on Notifications in the Symfony documentation.