Magento 2.3.0 How to get request parameters in event observer?

Question

I would like to get a request parameter in the observer file.

Below is the observer code.

etc/frontend/di.xml

<event name="review_save_before">
    <observer name="set_customer_data" instance="Namespace\Modulename\Observer\ReviewSaveBeforeObserver"/>
</event>

Observer/ReviewSaveBeforeObserver

<?php
namespace Namespace\Modulename\Observer;

use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;
use Magento\Review\Model\Review;
use Psr\Log\LoggerInterface;
use Magento\Sales\Api\Data\OrderInterface;
use Magento\Framework\App\Request\Http;

class ReviewSaveBeforeObserver implements ObserverInterface
{

    /**
     * @var Http
     */
    private $request;

    /**
     * @var OrderInterface
     */
    private $orderInterface;

    /** @var \Magento\Framework\Logger\Monolog */
    protected $logger;

    public function __construct(
        LoggerInterface $loggerInterface,
        OrderInterface $orderInterface,
        Http $request
    ) {
        $this->logger = $loggerInterface;
        $this->orderInterface = $orderInterface;
        $this->request = $request;
    }

    /**
     * This is the method that fires when the event runs.
     *
     * @param Observer $observer
     */
    public function execute(Observer $observer)
    {
        $this->logger->addDebug('Executed Review Save After Observer');

        /** @var Review $review */
        $review = $observer->getDataByKey('object');
        echo '<pre>';print_r($this->request->getParams());die;
        //$review->setStatusId(Review::STATUS_APPROVED);            
        $review->setCustomerId(1);        
    }
}

But it is throwing below error.

Fatal error: Uncaught Exception: User Error: Some transactions have not been committed or rolled back in /var/www/html/CE/2.3.0/vendor/magento/framework/DB/Adapter/Pdo/Mysql.php on line 3955 in /var/www/html/CE/2.3.0/vendor/magento/framework/App/ErrorHandler.php:61 Stack trace: #0 [internal function]: Magento\Framework\App\ErrorHandler->handler(256, 'Some transactio...', '/var/www/html/C...', 3955, Array) #1 /var/www/html/CE/2.3.0/vendor/magento/framework/DB/Adapter/Pdo/Mysql.php(3955): trigger_error('Some transactio...', 256) #2 [internal function]: Magento\Framework\DB\Adapter\Pdo\Mysql->__destruct() #3 {main} thrown in /var/www/html/CE/2.3.0/vendor/magento/framework/App/ErrorHandler.php on line 61

Any help would be appreciated!

Answer 1

It is because you have printed information in the observer. I think it is not because you have used getRequest() in the observer.

Try to see the result in this way.

$writer = new \Zend\Log\Writer\Stream(BP . '/var/log/test.log');
$logger = new \Zend\Log\Logger();
$logger->addWriter($writer);
$logger->info(print_r($this->request->getParams(), true));

And check in the test.log file. Do not print anything in the observer.

Answer 2

Try this way:

/**
 * @var \Magento\Framework\App\RequestInterface
 */
public $request;

public function __construct(
    ...
    \Magento\Framework\App\RequestInterface $request
){
    ...
    $this->request = $request;
}

public function execute(Observer $observer)
{
    $post = $this->request->getPost();
                /* or */
    $param = $this->request->getParam('parameter');
}

Answer 3

Try using

\Magento\Framework\App\RequestInterface::getParams()  

In replacement for:

\Magento\Framework\App\Request\Http::getParams()

Answer 4

Did you try with :

//\Magento\Framework\App\RequestInterface
$this->_request->getParam('field_name');

Its working for me. Hope it will work for you too.