Tutorial - Interacting with third party payment providers via Glue API

The checkout process of Spryker Glue API can be leveraged to involve third parties in the process of order confirmation. This can be required, for example, when the method of payment selected by the user requires additional steps to complete the purchase. These can include, but not limited to, card validation, processing a bank transfer, etc.

In this tutorial, you will find out how to invoke third parties in the API payment process.

1. Create new module

To implement third party interactions, first, you need to create a new module or extend an existing one. Let us create one on the Project level. The module needs to interact with 2 layers of Spryker Commerce OS: Glue (API) and Zed (backend). Thus, you need to create the following folders for module MyModule:

• src/Pyz/Glue/MyModule
• src/Pyz/Zed/MyModule

The module needs to implement 2 plugins:

1. A plugin that maps the response of the /checkout API endpoint and fills it with the necessary attributes.

2. A plugin to process the response of the payment service provider. The overall interaction diagram between Glue API, the API Client, and the third party is as follows:

2. Implement Checkout response mapper plugin

First, we need to implement a plugin that maps the checkout response and fills it with the necessary redirect URL and other attributes that are mapped. To do so, create a plugin file on the Glue layer: src/Pyz/Glue/MyModule/Plugin/CheckoutRestApi/CheckoutResponseMapperPlugin.php.

The plugin must implement the CheckoutResponseMapperPluginInterface. Using the the mapRestCheckoutResponseTransferToRestCheckoutResponseAttributesTransfer function of the interface, you can set the redirect URL and specify whether it is an internal or external redirect.

Sample implementation

<?php

namespace Pyz\Glue\MyModule\Plugin\CheckoutRestApi;

use Generated\Shared\Transfer\RestCheckoutResponseAttributesTransfer;
use Generated\Shared\Transfer\RestCheckoutResponseTransfer;
use Spryker\Glue\CheckoutRestApiExtension\Dependency\Plugin\CheckoutResponseMapperPluginInterface;
use Spryker\Glue\Kernel\AbstractPlugin;

class CheckoutResponseMapperPlugin extends AbstractPlugin implements CheckoutResponseMapperPluginInterface
{
    /**
     * @param \Generated\Shared\Transfer\RestCheckoutResponseTransfer $restCheckoutResponseTransfer
     * @param \Generated\Shared\Transfer\RestCheckoutResponseAttributesTransfer $restCheckoutResponseAttributesTransfer
     *
     * @return \Generated\Shared\Transfer\RestCheckoutResponseAttributesTransfer
     */
    public function mapRestCheckoutResponseTransferToRestCheckoutResponseAttributesTransfer(
        RestCheckoutResponseTransfer $restCheckoutResponseTransfer,
        RestCheckoutResponseAttributesTransfer $restCheckoutResponseAttributesTransfer
    ): RestCheckoutResponseAttributesTransfer {
        $restCheckoutResponseTransfer->getCheckoutResponse()->getRedirectUrl();

        $restCheckoutResponseAttributesTransfer
            ->setIsExternalRedirect($restCheckoutResponseTransfer->getCheckoutResponse()->getIsExternalRedirect())
            ->setRedirectUrl($restCheckoutResponseTransfer->getCheckoutResponse()->getRedirectUrl());

        return $restCheckoutResponseAttributesTransfer;
    }
}

3. Implement payload processor plugin

After a user completes payment verification, the payment service provider will submit a payload containing the relevant payment information. The payload will be submitted by the API client to the /order-payments endpoint.

To process the data, we need to implement another plugin on the Zed layer. The plugin will update the payment information in the database. Create a plugin file as follows: src/Pyz/Zed/MyModule/Communication/Plugin/OrderPaymentsRestApi/OrderPaymentUpdaterPlugin.php.

The plugin must extend the OrderPaymentUpdaterPluginInterface and implement the following two functions:

• isAppplicable—this function determines whether a specific payment is processed by the plugin. The function returns true if the payment must be processed; otherwise, it returns false.
• updateOrderPayment—this function updates the payment data in the database.

To help you understand which payments need to be processed, you can use the optional paymentIdentifier field in POST requests to the /order-payments endpoint. To make sure it is always present in a request, you may require the API client to set the field to a specific value to invoke your payment plugin. The value of the field can be retrieved using the getPaymentIdentifier helper function.

Sample implementation

<?php

namespace Pyz\Zed\MyModule\Communication\Plugin\OrderPaymentsRestApi;

use Generated\Shared\Transfer\UpdateOrderPaymentRequestTransfer;
use Generated\Shared\Transfer\UpdateOrderPaymentResponseTransfer;
use Spryker\Zed\Kernel\Communication\AbstractPlugin;
use Spryker\Zed\OrderPaymentsRestApiExtension\Dependency\Plugin\OrderPaymentUpdaterPluginInterface;

class OrderPaymentUpdaterPlugin extends AbstractPlugin implements OrderPaymentUpdaterPluginInterface
{
    /**
     * @param \Generated\Shared\Transfer\UpdateOrderPaymentRequestTransfer $updateOrderPaymentRequestTransfer
     *
     * @return bool
     */
    public function isApplicable(UpdateOrderPaymentRequestTransfer $updateOrderPaymentRequestTransfer): bool
    {
        if ($updateOrderPaymentRequestTransfer->getPaymentIdentifier()) {
            return true;
        }

        return false;
    }

    /**
     * @param \Generated\Shared\Transfer\UpdateOrderPaymentRequestTransfer $updateOrderPaymentRequestTransfer
     *
     * @return \Generated\Shared\Transfer\UpdateOrderPaymentResponseTransfer
     */
    public function updateOrderPayment(UpdateOrderPaymentRequestTransfer $updateOrderPaymentRequestTransfer): UpdateOrderPaymentResponseTransfer
    {
        $payload = $updateOrderPaymentRequestTransfer->getDataPayload();

        return (new UpdateOrderPaymentResponseTransfer())
            ->setIsSuccessful(true)
            ->setPaymentIdentifier($updateOrderPaymentRequestTransfer->getPaymentIdentifier())
            ->setDataPayload($updateOrderPaymentRequestTransfer->getDataPayload());
    }
}

4. Wire the plugins

Now, you need to wire the plugins so that they could be invoked during checkout. The Checkout Response Mapper Plugin needs to be registered in \Pyz\Glue\CheckoutRestApi\CheckoutRestApiDependencyProvider::getCheckoutResponseMapperPlugins():

...
    /**
     * @return \Spryker\Glue\CheckoutRestApiExtension\Dependency\Plugin\CheckoutResponseMapperPluginInterface[]
     */
    protected function getCheckoutResponseMapperPlugins(): array
    {
        return [
            ...
            new CheckoutResponseMapperPlugin
        ];
    }
...

The Payment Processor Plugin is registered in \Spryker\Zed\OrderPaymentsRestApi\OrderPaymentsRestApiDependencyProvider::getOrderPaymentUpdaterPlugins()

...
    /**
     * @return \Spryker\Zed\OrderPaymentsRestApiExtension\Dependency\Plugin\OrderPaymentUpdaterPluginInterface[]
     */
    protected function getOrderPaymentUpdaterPlugins(): array
    {
        return [
            ...
            new OrderPaymentUpdaterPlugin
        ];
    }
...

After wiring the plugins, the response of the /checkout endpoint will contain a correct redirect URL, and the /order-payments endpoint will process payloads received from the payment provider. Try accessing the endpoints to verify that the plugins process the data.