Is it possible to know what link a user clicked from inside a custom module observer?

Question

I'm trying to improve the sales pipeline of Magento 2 when allow guest checkout is disabled. By default after creating an account with allow guest checkout disabled, a user is redirected to the account center regardless of whether they clicked the account login button or the checkout button.

I would like to use an observer to redirect a user to the cart if they were prompted to log in after clicking on the cart button. Is there a way inside of my observer to know what link was clicked? (checkout or account)

I'm firing the following observer on customer_data_object_login.

Observer.php:

<?php
namespace Vendor\NameSpace\Observer;

use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;

class Redirect implements \Magento\Framework\Event\ObserverInterface
{

    protected $_responseFactory;
    protected $_url;
    protected $_session;

    public function __construct(
        \Magento\Customer\Model\Session $session,
        \Magento\Framework\App\ResponseFactory $responseFactory,
        \Magento\Framework\UrlInterface $url
    ) {
        $this->_session = $session;
        $this->_responseFactory = $responseFactory;
        $this->_url = $url;
    }

    public function execute(\Magento\Framework\Event\Observer $observer)
    {

        $isCustomerLoggedIn = $this->_session->isLoggedIn();

        if ($isCustomerLoggedIn) {
            $event = $observer->getEvent();
            $CustomRedirectionUrl = $this->_url->getUrl('checkout/cart');
            $this->_session->setBeforeAuthUrl($CustomRedirectionUrl);
            return $this;
        }
    }
}

Answer 1

If i understand your problem correct, you can change the behaviour of what happens after a user authenticates. In de backend go to Stores > Configuration > Customers > Customer Configuration > Login Options

Make sure the option Redirect Customers to Account Dashboard After Logging In is set to No. This way after logging in, the customer goes to the previous page.

If this is not the case and you need it for some other reason:

You will need to know what the current request/url is.

One way to get that is to use the \Magento\Framework\UrlInterface which I see you already have injected in your Observer. This has a method getCurrentUrl() which returns the (complete) current url. This can a bit tricky because it returns the uncleaned url and can have extra data like query parameters.

I would suggest you to inject \Magento\Framework\App\Request\Http which holds the current request information. This way you can get information about the current controller, action and route.

 $moduleName = $this->request->getModuleName();
 $controller = $this->request->getControllerName();
 $action     = $this->request->getActionName();
 $route      = $this->request->getRouteName();

Now, if you see that the combination of controller, action and route is what you try to hide, you can redirect the user.