annotations.md

Annotations

The following annotations are available in the event package.

Observer(string $event[, int $priority[, bool $once]])

When declared, the Observer annotation will automatically subscribe a class method as an observer to a specific event. The annotation accepts three arguments, the first being the event key, the second being the priority level (optional), and the last being the once flag (optional).

The class in which the annotations are declared must implement the Titon\Event\Subject interface for this to work correctly. The annotations should only be declared on methods.

class Foo implements Titon\Event\Subject {
    use Titon\Event\EmitsEvents;

    <<Observer('init')>>
    public function doAction(Event $event): mixed {
        // ...
    }
}

Once the annotations are declared, we can wire them in the constructor, which in turn triggers the automatic subscribing.

class Foo implements Titon\Event\Subject {
    use Titon\Event\EmitsEvents, Titon\Annotation\WiresAnnotations;

    public function __construct() {
        $this->wireAnnotations();
    }

    // ...
}

For a better understanding of this annotation, here are a few declaration examples.

<<Observer('init')>>
<<Observer('init', 15)>>
<<Observer('init', 25, true)>>