Magento 2 — Module — Create Observer

Observer is a feature of Magento 2 Module to make an action on events such as User adds product to cart, User logins, etc.

So, how to make it?

1. Create etc/events.xml file

You can make them into a different areas:

• Global Area : <root>/etc/events.xml
• Front-End Area : <root>/etc/frontend/events.xml
• Back-End Area : <root>/etc/adminhtml/events.xml

Here’s a simple example of this file :

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="<magento_event_name>">
        <observer name="<VendorName_ModuleName_ObserverName>" instance="<VendorName>\<ModuleName>\Observer\<ClassName.php>" />
    </event>
</config>

You can see what events Magento has here :

https://www.simicart.com/blog/magento-2-events-list/

2. Create Observer Class

Create a Class that has execute method on it. Why? Because Magento 2 will automatically calls execute method. Here’s the example :

<?php
namespace <VendorName>\<ModuleName>\Observer;
use \Magento\Framework\Event\ObserverInterface;
use \Magento\Framework\Event\Observer;
class CustomerLogin implements ObserverInterface
{
    public function execute(Observer $observer)
    {
        // Type your code here
        echo "Customer LoggedIn Cuk, ";
        $customer = $observer->getEvent()->getCustomer();
        echo $customer->getName(); //Get customer name
        exit;
    }
}

Don’t forget to flush the cache! And run it.