Logout by programming from observer in magento 2

Question

How to logout from customer session by programming from observer in magento 2?

Answer 1

It's quite similar to the answer for the same question applied to Magento 1: you need to call the Customer session model's logout method. Just create a resultRedirect and force headers after.

For an example of logging out, ref. \Magento\Customer\Controller\Account\Logout::execute():

public function execute()
{
    $lastCustomerId = $this->session->getId();
    $this->session->logout()->setBeforeAuthUrl($this->_redirect->getRefererUrl())
        ->setLastCustomerId($lastCustomerId);

    /** @var \Magento\Framework\Controller\Result\Redirect $resultRedirect */
    $resultRedirect = $this->resultRedirectFactory->create();
    $resultRedirect->setPath('*/*/logoutSuccess');
    return $resultRedirect;
}

Answer 2

You have to write this below code in your module's Observer folder.

Vendor/MyModule/Observer/CustomerLogoutObserver.php

<?php

namespace Vendor\MyModule\Observer;

use Magento\Framework\Event\ObserverInterface;
use Magento\Framework\Event\Observer;
use Magento\Framework\UrlInterface;
use Magento\Framework\App\ResponseInterface;
use Magento\Framework\App\Response\RedirectInterface;

class CustomerLogoutObserver implements ObserverInterface
{
    /**
     * @param \Magento\Framework\ObjectManagerInterface $objectManager
     */
    protected $_objectManager;

    /**
     * @param  \Magento\Framework\App\ResponseFactory $responseFactory
     */
    protected $_responseFactory;


    /**
     * @param \Magento\Framework\UrlInterface $url
     */
    protected $_url;

    /*
     * @param \Magento\Framework\App\ResponseInterface $response
     */
    protected $_response;

    /**
     * @var \Magento\Framework\UrlInterface
     */
    protected $_urlInterface;


     /**
     * @var \Psr\Log\LoggerInterface
     */
    protected $logger;


    /**
     * CustomerLogoutObserver constructor.
     * @param \Magento\Framework\ObjectManagerInterface $objectManager
     * @param \Magento\Framework\App\ResponseFactory $responseFactory
     * @param \Magento\Framework\UrlInterface $url
     * @param \Magento\Framework\App\ResponseInterface $response
     */
    public function __construct(
        \Magento\Framework\ObjectManagerInterface $objectManager,
        \Magento\Framework\App\ResponseFactory $responseFactory
        \Magento\Framework\App\ResponseInterface $response,
        UrlInterface $urlInterface,
        RedirectInterface $redirect,
        \Psr\Log\LoggerInterface $logger,
        \Magento\Customer\Model\Session $customerSession    
    ) {
        $this->_objectManager = $objectManager;
        $this->_responseFactory = $responseFactory;
        $this->_response = $response;
        $this->_urlInterface=$urlInterface;
        $this->_redirect=$redirect;
        $this->logger = $logger;
        $this->customerSession=$customerSession;
    }

     public function execute(\Magento\Framework\Event\Observer $observer)
    {
        try {
            $customer = $observer->getEvent()->getData('customer');
            $customerGroup = $customer->getGroupId();
            $customerId= $this->customerSession->getCustomer()->getId();  
            $url = $this->_urlInterface->getUrl('customer/account/login');

             if($customerId) {
                $this->customerSession->destroy(); 
                $this->_responseFactory->create()->setRedirect($url)->sendResponse();

            } 

        }
    }

}

then, Write an event for logout in events.xml in

Vendor/MyModule/etc/events.xml

<?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="customer_logout">
        <observer name="customer_logout_redirection"
                  instance="Vendor\MyModule\Observer\CustomerLogoutObserver" />
    </event>

</config>

Answer 3

Try this, Its working for me.

public function execute() {
        $lastCustomerId = $this->session->getId();
        try {
            $this->session->logout()->setBeforeAuthUrl($this->_redirect->getRefererUrl())->setLastCustomerId($lastCustomerId);
        } catch (\Magento\Framework\Exception\NoSuchEntityException $e) {
            $resultRedirect = $this->resultRedirectFactory->create();
            $resultRedirect->setPath('*/*/logoutSuccess');
            return $resultRedirect;
        }

        if ($this->getCookieManager()->getCookie('mage-cache-sessid')) {
            $metadata = $this->getCookieMetadataFactory()->createCookieMetadata();
            $metadata->setPath('/');
            $this->getCookieManager()->deleteCookie('mage-cache-sessid', $metadata);
        }

        /** @var \Magento\Framework\Controller\Result\Redirect $resultRedirect */
        $resultRedirect = $this->resultRedirectFactory->create();
        $resultRedirect->setPath('*/*/logoutSuccess');
        return $resultRedirect;
    }