Services

The OXID eShop uses the Symfony DI Container to handle services. For more information about DI Container refer to the Symfony DI Container documentation

In a module, you can:

Define service

For example, you need to adjust the price calculation of the product. You can define a single responsible service for this:

interface PriceCalculatorInterface
{
    public function getPrice(string $productId, int $amount): Price;
}

class ERPPriceCalculator implements PriceCalculatorInterface
{
    public function getPrice(string $productId, int $amount): Price
    {
        $this->doSomeCalculation();
        // ...
        return $price
    }
}

Register service

Then you can register the service in OXID DI Container. Create in root directory of your module services.yaml file and register it there:

services:
    SomeCompany\SpecialERPModule\PriceCalculatorInterface:
        class: SomeCompany\SpecialERPModule\ERPPriceCalculator
        autowire: true
        public: true

We recommend to use the interface namespace as the DI container key for the service if you have only the one implementation for an interface and provide class parameter with the implementation namespace. So we can inject with autowiring an interface as dependency in our classes and avoid dependencies on implementations (dependency inversion principle).

public function __constructor(PriceCalculatorInterface $priceCalculator)
{
    $this->priceCalculator = $priceCalculator;
}

In this example we have dependency on PriceCalculatorInterface (abstraction), but not on ERPPriceCalculator (implementation). PriceCalculatorInterface will be autowired and no changes in the yaml file are needed because the key of the service is the same as provided in the constructor argument type.

Inject own, third party module or shop services

You can use your own, shop services or even services of other modules via dependency injection.

use Psr\Log\LoggerInterface;

class ERPPriceCalculator implements PriceCalculatorInterface
{
    private $shopLogger;

    public function __constructor(LoggerInterface $shopLogger)
    {
        $this->shopLogger = $shopLogger;
    }

    public function getPrice(string $productId, int $amount): Price
    {
        $this->shopLogger->info('Log something');

        $this->doSomeCalculation();
        // ...
        return $price;
    }
}

In this example a shop service with id ‘PsrLogLoggerInterface’ will be autowired and no changes in the yaml file are needed, because the key of the logger service is the same as provided in the constructor argument type.

Use services in standard classes

Now you have a service and want to use it to extend already existing shop functionality. You can create own Article class where you overwrite the getPrice() method:

class ERPArticle extends Article_parent
{
    public function getPrice($amount = 1)
    {
        $container = ContainerFactory::getInstance()->getContainer();

        $erpPriceCalculator = $container->get(PriceCalculatorInterface::class);
        return $erpPriceCalculator->getPrice($this->getId(), $amount)
    }
}

You just fetch the DI container via the ContainerFactory and then fetch your service. In order to obtain the service, it needs to be marked as public.