Question 6422 in Magento Question posted in
The official documentation can be found here.

Magento 2 Message Queue – Type Error with expected string, null given

I struggle for 3 days now to get a simple Message Queue in Magento 2 to work. Here are my XML files:

communication.xml:

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:Communication/etc/communication.xsd">
    <topic name="erp.queue.order"
           request="string">
        <handler name="erp.queue.order"
                 type="TimoGOrderTransferModelQueueConsumer"
                 method="process" />
    </topic>
</config>

queue_consumer.xml:

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework-message-queue:etc/consumer.xsd">
    <consumer name="erp.queue.order"
              queue="erp.queue.order"
              connection="db"
              handler="TimoGOrderTransferModelQueueConsumer::process"/>
</config>

queue_publisher.xml:

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework-message-queue:etc/publisher.xsd">
    <publisher topic="erp.queue.order">
        <connection name="db"
                    exchange="magento-db"
                    disabled="false"/>
    </publisher>
</config>

queue_topology.xml:

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework-message-queue:etc/topology.xsd">
    <exchange name="magento-db"
              type="topic"
              connection="db">
        <binding id="TimoGErpOrderTransfer"
                 topic="erp.queue.order"
                 destinationType="queue"
                 destination="erp.queue.order"/>
    </exchange>
</config>

So adding messages to the queue works (I see it in the database table "queue_message"), however when I execute php bin/magento queue:consumers:start erp.queue.order I always get the following exception:

Type Error occurred when creating object: MagentoFrameworkMessageQueueConsumerConfigData, Argume
  nt 2 passed to MagentoFrameworkReflectionTypeProcessor::resolveFullyQualifiedClassName() must be o
  f the type string, null given, called in /Users/timog/Sites/magento2.local/vendor/magento/fra
  mework/Reflection/TypeProcessor.php on line 545

My consumer test code:

<?php

namespace TimoGOrderTransferModelQueue;

use Exception;
use PsrLogLoggerInterface;
use MagentoFrameworkSerializeSerializerJson;

class Consumer
{

    private $_logger;
    private Json $_json;


    public function __construct(
        LoggerInterface $logger,
        Json $json
    )
    {
        $this->_json = $json;
        $this->_logger = $logger;
    }


    public function process($request)
    {
        try {
            $test = $this->_json->unserialize($request);
        } catch (Exception $exc) {
            $this->_logger->critical($exc->getMessage());
        }
    }
}

I have no idea what’s wrong and I really need help please… it’s frustrating…

Thank you!

Tags:

2

Answers


  1. 0

    Have you created a custom module with module.xml and registration.xml files as required in the official documentation?

    Have you run the bin/magento setup:upgrade and bin/magento cache:flush commands to make sure that the module is properly installed and the database entries are not cached?

    Are you working with PHPStorm? You can run bin/magento dev:urn:generate .idea/misc.xml to add XSL schema to your IDE config so that it can highlight XML syntax, very useful for XML configuration files.

    EDIT: URN schema generation for XML verification.

    Login or Signup to reply.
  2. 0

    Probably, after more than 3 months, you already solved your problem, but you just needed to set a type for the $request parameter, or to write the PHP Docblock (the comment with @param and @return) before the process function in your consumer’s class.

    Magento 2, most of the time, uses reflections to validate the type of parameters and returns, taking advantage of the comment before each method/property to retrieve the actual data type.

    So basically you should just change your method declaration to this:

    /**
 * @param string $request
 * @return void
 */
public function process($request)

    or this:

    public function process(string $request): void
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search