How to subscribe to predispatch of registration in Shopware 6 just like shopware 5?

Question

I want to call a function right before the registration process starts in order to check some values from the registration form. In Shopware 5 I would use a predispatch event for that. How to do that in Shopware 6?

This is the method into which the form posts the registration data to:

/**
 * @Route("/account/register", name="frontend.account.register.save", methods={"POST"})
 * @Captcha
 */
public function register(Request $request, RequestDataBag $data, SalesChannelContext $context): Response
{

Answer 1

Check the class Shopware\Core\Checkout\Customer\CustomerEvents. MAPPING_REGISTER_CUSTOMER should be the one you are looking for.

<?php

namespace Vendor\Plugin\Subscriber;

use Shopware\Core\Checkout\Customer\CustomerEvents;
use Shopware\Core\Framework\Event\DataMappingEvent;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

class RegisterSubscriber implements EventSubscriberInterface
{
    public static function getSubscribedEvents(): array
    {
        return [
            CustomerEvents::MAPPING_REGISTER_CUSTOMER => 'onRegister'
        ];
    }

    public function onRegister(DataMappingEvent $event)
    {
        $input = $event->getInput();
        $output = $event->getOutput();

        // do whatever you want here with the output

        $event->setOutput($output);

        return true;
    }
}

The subscriber is registered in services.xml like this, similar to Shopware 5, except the ID is the FQDN of the subscriber class:

    <!-- Event Subscribers -->
    <service id="Vendor\Plugin\Subscriber\RegisterSubscriber">
        <tag name="kernel.event_subscriber"/>
    </service>

Answer 2

I think the earliest event on which you can subscribe it is framework.validation.customer.create. It is dispatched at RegisterRoute::getCustomerCreateValidationDefinition(). In subscriber you can extend validation constraints. if you need to do something earlier i think the best solution is to override/decorate RegisterRoute.

You can check my answer there How to extend Shopware 6 controller action, it may help also.