Magento 2 Events: A Beginner’s Guide

In Magento 2, events are an integral part of the platform’s architecture. They allow developers to modify or extend the functionality of Magento 2 core code or third-party modules without making direct modifications to the source code. Events are also useful for triggering actions when specific events occur, such as when a product is saved or when a customer is created.

This article provides a beginner’s guide to Magento 2 events, including how to use them and some common use cases.

What Are Events in Magento 2?

Events in Magento 2 are hooks that are triggered at specific points in the code’s execution. These hooks allow custom code to be executed at specific points in the application’s lifecycle. When an event is triggered, any observer or listener classes that are registered to that event are executed. This provides developers with a way to modify or extend the behavior of the application without modifying the core code.

Events in Magento 2 are based on the Observer pattern, which is a design pattern commonly used in object-oriented programming. In the Observer pattern, an object (the subject) maintains a list of other objects (the observers) and notifies them automatically of any state changes. In Magento 2, the subject is the object that dispatches the event, and the observer is the class that contains the code that is executed when the event is triggered.

How to Use Events in Magento 2

Events in Magento 2 are dispatched using the Magento\Framework\Event\Manager class. This class provides the dispatch() method, which is used to trigger an event. The dispatch() method takes two arguments: the name of the event and an array of additional data that can be passed to the event’s observers.

To listen for an event, you must create an observer class that implements the Magento\Framework\Event\ObserverInterface interface. This interface has a single method, execute(), which is called when the event is triggered. The execute() method is passed an instance of the Magento\Framework\Event\Observer class, which contains information about the event that was triggered.

To register your observer class with an event, you must add an <event> tag to your module’s XML configuration file. The <event> tag specifies the name of the event and the name of the observer class.

Example Use Cases

Here are some common use cases for events in Magento 2:

1. Modifying the behavior of an existing module – Events can be used to modify the behavior of a third-party module without modifying its source code. For example, you could use an event to add an extra validation step when a customer is saved.
2. Extending the functionality of Magento 2 core code – Events can also be used to extend the functionality of the Magento 2 core code. For example, you could use an event to add a new payment method to the checkout.
3. Sending notifications when specific events occur – Events can be used to trigger notifications when specific events occur. For example, you could use an event to send an email to the store owner when a new customer is created.

Example

here’s an example of a custom event that can be used in Magento 2:

<event name="custom_event_name">
    <observer name="custom_observer_name" instance="Vendor\Module\Observer\CustomObserver" />
</event>

This XML configuration defines a new custom event named custom_event_name that can be triggered in Magento 2. When the event is triggered, it will execute the execute() method of the CustomObserver class, which is located in the Vendor\Module\Observer namespace.

To trigger this custom event in your code, you would use the following code:

$this->_eventManager->dispatch('custom_event_name');

This will trigger the custom_event_name event and execute the execute() method of the CustomObserver class. You can also pass additional data to the event by passing an array of arguments as the second parameter of the dispatch() method.

Using custom events in Magento 2 allows you to extend the functionality of the platform and create custom functionality that can be triggered at specific points in the code.

Conclusion

Events in Magento 2 are a powerful tool that allow developers to modify or extend the behavior of the platform’s core code or third-party modules. By using events, developers can ensure that their customizations are kept separate from the core code, making it easier to upgrade to new versions of the platform in the future. Events are also useful for triggering actions when specific events occur, such as when a product is saved or when a customer is created. With this beginner’s guide to Magento 2 events, you should have a good understanding of how they work and how they can be used.