concept-activities.md

Activities

Activities record noteworthy things that happened in a content container — "X created a post", "Y joined the space", "Z liked a comment". Each activity is rendered into a stream entry and may also appear in the daily summary email.

The two related concepts:

• Activity — bound to a ContentContainer, not targeted at a specific user. Anyone with access to the container sees it. Compare with notifications, which target a specific user.
• Originator — the user the activity is about (e.g. the comment author).
• Source — an optional Content or ContentAddon the activity describes. When a source is set, the activity inherits its visibility and other content properties.

Implementing an activity

Place activity classes under your module's activities/ directory.

1. The activity class

namespace johndoe\example\activities;

use humhub\modules\activity\components\BaseActivity;

class SomethingHappened extends BaseActivity
{
    public $viewName = 'somethingHappened';   // view file (without .php)
    public $moduleId = 'example';             // required
}

2. The view file

By default the view sits at activities/views/<viewName>.php. It receives $originator, the source record, and a few helpers:

use yii\helpers\Html;

echo Yii::t('ExampleModule.activity', '{user} did something cool.', [
    '{user}' => '<strong>' . Html::encode($originator->displayName) . '</strong>',
]);

For a different mail rendering, ship a activities/views/mail/<viewName>.php with the same view name — BaseActivity picks it up automatically when generating the summary mail.

3. Firing the activity

SomethingHappened::instance()
    ->from($user)        // originator
    ->about($this)       // source (Content or ContentAddon)
    ->create();

create() persists the activity, dispatches stream entries, and queues mail delivery if applicable. Activities are typically fired from the afterSave() hook of the source record — once per state transition, never on every save.