Notifications are used to inform one or a given set of users about a specific event in your network as the liking of a post or mentioning of a user over multiple channels (e.g. web and mail).

Custom notification classes are derived from humhub\modules\notification\components\BaseNotification. A humhub\modules\notification\components\BaseNotification usually is assigned with an $originator user instance and a $source instance, which connects the Notification with a Content or any other kind of yii\db\ActiveRecord.

A Notification can be sent to a user by calling the send() or sendBulk() function. This will persist an humhub\modules\notification\models\Notification instance for each user send out a notification to all allowed NotificationTargets.

Note: Unlike Activities which are targeted for multiple users e.g. all Users of a Space, a Notification Model instance is always related to a single user.

Examples for core notifications are:

  • humhub\modules\like\notifications\NewLike: is sent if an user likes a post or comment.
  • humhub\modules\user\notifications\Followed: is sent if an user follows another user.
  • humhub\modules\user\notifications\Mentioned: is sent if an user is mentioned within an post or comment.
  • humhub\modules\content\notifications\ContentCreated: is sent when content (e.g. a post) was created.

Custom Notifications

Notification Class

Custom Notifications are derived from humhub\modules\notification\components\BaseNotification and should reside in the notifications subfolder of your module's root directory.

The notification class at least has to overwrite the $moduleId variable with the id of your module and the.


namespace johndoe\example\notifications;

use humhub\modules\notification\components\BaseNotification;

 * Notifies a user about something happend
class SomethingHappend extends BaseNotification
    // Module Id (required)
    public $moduleId = "example";

    // Viewname (required)
    public $viewName = "somethingHappend";

Notification View

By default, the view of a notification should be located inside the subfolder notifications/views. The view of the example above should therefore be located in /modules/examples/notifications/views/somethingHappened.php.


use yii\helpers\Html;

echo Yii::t('SomethingHappend.views_notifications_somethingHappened', "%someUser% did something cool.", [
    '%someUser%' => '<strong>' . Html::encode($originator->displayName) . '</strong>'

Info: If you require a different notification view for mails, you have to add an extra view file to a subfolder notifications/views/mail.

Send Notifications

After an event was triggered, you'll have to instantiate your custom humhub\modules\notification\components\BaseNotification and call its send or sendBulk function which will instantiate and persist a humhub\modules\notification\models\Notification instance for each user you want to notify.

A notification can optionally be assigned with a $source model instance (e.g. a post or comment related to the notification) which has to be derived from yii\db\ActiveRecord.

// Sending to a single user

// Sending to multiple users

Info: The send and sendBulk will create and persist a humhub\modules\notification\models\Notification instance for each user.

Tip: Notifications are often created and sent within the afterSave hook of the related source instance. This should be prefered over the instantiation within a controller.

Note: Notifications are only sent to a specific NotificationTarget depending on the user's account settings.