Shopware 6: Tax Free with domestic delivery in DE (TaxDecorator & CartRuleLoader) - shopware6

Question

Some customers with a domestic shipping address within Germany are still tax exempt (e.g. NATO, or US Army).
Since this is considered an export delivery.
How can this be implemented? The only solution I have found is to completely override/replace CartRuleLoader
What I have done so far: I created a custom field in Customers, where a store editor can specify a customer as tax free (even within Germany).
Then I overwrote the class TaxDetector:
class TaxDetector extends \Shopware\Core\Checkout\Cart\Tax\TaxDetector
{
public function isNetDelivery(SalesChannelContext $context): bool
{
$customer = $context->getCustomer();
if ($customer && ($cf = $customer->getCustomFields()) && !empty($cf['mycustomfield']) && $cf['mycustomfield'] === 'nato') {
return true;
}
return parent::isNetDelivery($context);
}
public function getTaxState(SalesChannelContext $context): string
{
$customer = $context->getCustomer();
if ($customer && ($cf = $customer->getCustomFields()) && !empty($cf['mycustomfield']) && $cf['mycustomfield'] === 'nato') {
return CartPrice::TAX_STATE_FREE;
}
return parent::getTaxState($context);
}
}
The problem is that Shopware 6 checks the validity of the tax status in CartRuleLoader when completing an order. And here the test is done in private functions that I cannot override.
load -> validateTaxFree -> detectTaxType
Any suggestions on how to solve this more eligant and futerprove then override all CartRuleLoader?

Answer 1

This is indeed a little tricky.
When you look at the method CartRuleLoader::detectTaxType you can find these lines:
$currency = $context->getCurrency();
$currencyTaxFreeAmount = $currency->getTaxFreeFrom();
$isReachedCurrencyTaxFreeAmount = $currencyTaxFreeAmount > 0 && $cartNetAmount >= $currencyTaxFreeAmount;
if ($isReachedCurrencyTaxFreeAmount) {
return CartPrice::TAX_STATE_FREE;
}
It's arguably a little hacky but you could "trick" Shopware to return the tax free state by setting the tax free amount of the currency to a minimal amount.
Therefore you could decorate Shopware\Core\System\SalesChannel\Context\SalesChannelContextFactory.
<service id="MyPlugin\Core\System\SalesChannel\Context\SalesChannelContextFactoryDecorator" decorates="Shopware\Core\System\SalesChannel\Context\SalesChannelContextFactory" decoration-priority="-999">
<argument type="service" id="MyPlugin\Core\System\SalesChannel\Context\SalesChannelContextFactoryDecorator.inner"/>
</service>
In the decorator you could then have your logic and set the tax free amount:
<?php declare(strict_types=1);
namespace MyPlugin\Core\System\SalesChannel\Context;
use Shopware\Core\Checkout\Cart\Price\Struct\CartPrice;
use Shopware\Core\System\SalesChannel\Context\AbstractSalesChannelContextFactory;
use Shopware\Core\System\SalesChannel\SalesChannelContext;
class SalesChannelContextFactoryDecorator extends AbstractSalesChannelContextFactory
{
private AbstractSalesChannelContextFactory $decorated;
public function __construct(
AbstractSalesChannelContextFactory $decorated,
) {
$this->decorated = $decorated;
}
public function getDecorated(): AbstractSalesChannelContextFactory
{
return $this->decorated;
}
public function create(string $token, string $salesChannelId, array $options = []): SalesChannelContext
{
$context = $this->getDecorated()->create($token, $salesChannelId, $options);
// ... your logic
if (...) {
$context->getCurrency()->setTaxFreeFrom(0.00001);
$context->setTaxState(CartPrice::TAX_STATE_FREE);
}
return $context;
}
}
Edit: It looks like this could not be enough as there is a security check which checks if the previous state wasn't tax free and resets it otherwise.
if ($previous !== CartPrice::TAX_STATE_FREE) {
$context->setTaxState($previous);
}
You might have to additionally set the tax state inside your decorator (updated the above example). The tax free amount would then make it stick.