events.md

Events

As known from the Doctrine ORM project, this library makes use of Events.

Available Events

• prePersist - Fires before an entity is persisted
• postPersist - Fires after an entity is persisted
• preRelationCreate - Fires before a relation is created
• postRelationCreate - Fires after a relation is created
• preStmtExecute - Fires before a statement (query) is executed
• postStmtExecute - Fires after a statement (query) is executed
• preRemove - Fires before an entity is removed
• postRemove - Fires after an entity is removed
• preRelationRemove - Fires before a relation is removed
• postRelationRemove - Fires after a relation is removed

Usage

The usage of those events is quiet simple. First you have to create an EventListener. This is a class containing functions, named after the events. If you want to listen for prePersist for example, your listener looks like this:

use HireVoice\Neo4j\Event as Events;

class PrePersistListener
{
    public function prePersist(Events\PrePersist $event)
    {
        $entity = $event->getEntity();

        // do your stuff here...
    }
}

Of course, you can listen to more then one event. See the full example below.

In a second step, the listener must be passed to an EventManager instance. After the listener was added, inject the EventManager into the EntityManager:

use \Doctrine\Common\EventManager;

// ...

$eventManager = new EventManager();
$listener = new PrePersistListener();

$eventManager->addEventListener(
    array('prePersist'), // array of all listened events
    $listener // instance of your event listener
);

$entityManager->setEventManager($eventManager);

Heads Up: This wire-up should usually be done using a Dependency Injection Container...

The implementation bases on the Doctrine Common API Event Manager. More documentation there...

Full EventListener example

use HireVoice\Neo4j\Event as Events;

class ExampleEventListener
{
    public function prePersist(Events\PrePersist $event)
    {
        return null;
    }

    public function postPersist(Events\PostPersist $event)
    {
        return null;
    }

    public function preRelationCreate(Events\PreRelationCreate $event)
    {
        return null;
    }

    public function postRelationCreate(Events\PostRelationCreate $event)
    {
        return null;
    }

    public function preStmtExecute(Events\PreStmtExecute $event)
    {
        return null;
    }

    public function postStmtExecute(Events\PostStmtExecute $event)
    {
        return null;
    }

    public function preRemove(Events\PreRemove $event)
    {
        return null;
    }

    public function postRemove(Events\PostRemove $event)
    {
        return null;
    }

    public function preRelationRemove(Events\PreRelationRemove $event)
    {
        return null;
    }

    public function postRelationRemove(Events\PostRelationRemove $event)
    {
        return null;
    }
}