Yii2: ActiveRecord events that only trigger on a scenario - events

Question

Has anyone ever needed to bind an ActiveRecord event handler in a way that it only triggers on certain scenarios?
In an ideal world the ActiveRecord on() method would also take a $scenarios parameter and trigger the handler only if the ActiveRecord is using that scenario at the time the event occurs. But since that is not the case I am looking for a clean, reliable way to implement this type of functionality.
Edit: This needs to work with any event, including built-in events triggered by the Yii framework (eg. ActiveRecord::EVENT_AFTER_INSERT).

Answer 1

This improvement of my first comment.
class ScenarioEvent extends \yii\base\Event
{
private static $_events = [];
public static function onScenario($scenario, $class, $name, $handler, $data = null)
{
// You may use foreach if you wil use many scenarios for event
if (!isset(self::$_scenarios)) {
self::$_scenarios[$scenario] = [];
}
self::$_scenarios[$scenario][$name][] = $class;
return static::on($class, $name, $handler, $data);
}
public static function trigger($class, $name, $event = null)
{
if (
// If event is null assumed that it has no sender with scenario
$event === null
|| empty(self::$_scenarios[$event->sender->scenario][$name])
) {
parent::trigger($class, $name, $event);
} else {
$classes = array_merge(
[$class],
class_parents($class, true),
class_implements($class, true)
);
foreach ($classes as $class) {
if (in_array($class, self::$_scenarios[$event->sender->scenario][$name])) {
parent::trigger($class, $name, $event);
break;
}
}
}
}
}