Add events

When adding an event, make sure you first decide what kind of events you want to trigger in your code. You define events in a class by declaring their literal string values, such as ModuleName.subject.action. An event’s value uniquely identifies an event. All listeners attached to an event are executed when a module triggers an event.

For example, to perform an action before persisting a product abstract entity, do the following:

1. Create a class to hold all the module events: Spryker\Shared\Product\ProductConfig.php
2. Add the following constant ProductConfig::PRODUCT_ABSTRACT_BEFORE_CREATE with the value Product.product_abstract.before.create. The first part in this example value is the module name, then the subject, and lastly the action. You can define any unique name, just keep it literal for the sake of code clarity.
3. Trigger the event before the entity is persisted using the event facade \Spryker\Zed\Event\EventFacadeInterface::trigger method which accepts two arguments: eventName, which is the name of the event we created before ProductConfig::PRODUCT_ABSTRACT_BEFORE_CREATE and TransferInterface, which is the transfer object you want to pass to the event listener.

class ProductStorageConfig extends AbstractBundleConfig
{
    /**
     * @uses ProductConfig::PRODUCT_ABSTRACT_BEFORE_CREATE // primary constant
     *
     * @var string
     */
    public const PRODUCT_ABSTRACT_BEFORE_CREATE = 'Product.product_abstract.before.create'; // secondary constant
}