How do I capture GraphQL POST data?

Question

I'm trying to debug an issue with a custom GraphQL module. I want to log the POST data that's being sent to it. I know it is being sent, because the response works OK for the most part. There's just a small language issue, which could form a question in itself, but as it's custom code it would take a small dissertation to explain.

So for this question I just want to focus on why, when I call $this->request->getPost(), I get an empty object.

Here's my code:

<?php

declare(strict_types=1);

namespace Mycompany\CatalogGraphQl\Model\Resolver\DataProvider;

use Magento\Catalog\Api\ProductRepositoryInterface;
use Magento\Store\Model\StoreManagerInterface;
use Magento\Framework\App\RequestInterface;


class ConfigurableProduct {

    private $productRepository;
    private $storeManager;
    private $request;

    public function __construct(
        ProductRepositoryInterface $productRepository,
        StoreManagerInterface $storeManager,
        RequestInterface $request
    ) {
        $this->productRepository = $productRepository;
        $this->storeManager = $storeManager;
        $this->request = $request;
    }

    public function getData($productSku) {
    
        // quick and dirty logging
        $logfile = "/tmp/magento.log";
        file_put_contents($logfile, print_r($this->request->getParams(), TRUE), FILE_APPEND);
        file_put_contents($logfile, print_r($this->request->getPost(), TRUE), FILE_APPEND);
        file_put_contents($logfile, print_r($_POST, TRUE), FILE_APPEND);
        
        $currentStoreId = $this->storeManager->getStore()->getID();
        $product = $this->productRepository->get($productSku, false, $currentStoreId, true);
        return [
            'master' => $product->getData(),
            'type_id' => $product->getTypeId(),
            'row_id' => $product->getRowId(),
            'model' => $product
        ];

    }

}

As you can see I'm trying to log $this->request->getPost(), $this->request->getParams() and even $_POST. $_POST is an empty array. getParams() gives me only query string parameters. And getPost() gives me this:

Laminas\Stdlib\Parameters Object
(
    [storage:ArrayObject:private] => Array
        (
        )

)

Why is it not letting me get at the POST data?

Answer 1

It seens Magento doesn't treats GraphQL requests as "POST" requests but the implementation of RequestInferface used in your request attribute is Magento\Framework\App\Request\Http and it implements Magento\Framework\App\RequestContentInterface, so try to use $this->request->getContent() instead.