creode/magento2-messagequeue

Magento 2 Message Queue

A simple system for passing and processing messages in Magento 2., _(*1)

Comes with classes to queue messages during normal site usage, and to process queues in cron jobs, _(*2)

There is only one queue, but messages can be grouped using the setGroup() method., _(*3)

Usage

Adding a message to the queue

# inject a queue factory into your constructor
public function __construct(
    \Creode\MessageQueue\Model\MessagequeueFactory $messageQueueFactory
) {
    $this->messageQueueFactory = $messageQueueFactory;
}

function createAMessage() {
    $message = $this->messageQueueFactory->create();

    # create messages with waiting status so they'll be picked up when processing the queue
    $message->setStatus(\Creode\MessageQueue\Model\Messagequeue::STATUS_WAITING)
        ->setMessage('a message for Creodes group')
        ->setGroup(\Your\Module\Cron\ProcessCreodesGroup::MESSAGE_GROUP) # it's recommended to use the class constant for message group
        ->setCreationTime(time())
        ->save();
}

Processing messages in a cron job

Your/Module/etc/crontab.xml

<?xml version="1.0" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Cron:etc/crontab.xsd">
    <group id="message-queue-processing">
        <job instance="Your\Module\Cron\ProcessCreodesGroup" method="execute" name="creode_processqueue_creodesgroup">
            <schedule>*/5 * * * *</schedule>
        </job>
    </group>
</config>

Your/Module/Cron/ProcessCreodesGroup.php

When extending Creode\MessageQueue\Cron\ProcessQueue your cron job class only needs a single method - processMessage, _(*4)

Messages that are picked up have the status waiting, _(*5)

Messages are automatically marked as processing when the job picks them up. Further runs will not pick up messages that are already being processed., _(*6)

The message will be marked completed if the processMessage method completes without error., _(*7)

If an exception is thrown in processMessage, the message processing will be aborted and the message added back into the queue by setting to the waiting status., _(*8)

Messages can fail up to 5 times, at which point they are marked failed and will not be processed in future runs., _(*9)

<?php

namespace Your\Module\Cron;

use Creode\MessageQueue\Cron\ProcessQueue;
use Creode\MessageQueue\Model\Messagequeue as Message;

class ProcessCreodesGroup extends ProcessQueue
{
    const MESSAGE_GROUP = 'creodes_group';

    /**
     * @inheritdoc
     */
    protected function processMessage(Message $message)
    {
        # write your code here to do _the thing_ you need the queue for

        # log the message
        $this->logger->debug('Processing Creodes Group message with contents ' . $message->getMessage());

        # your message could be an order id, customer id etc. and you can load the object
        # by injecting a repository into the constructor (but don't forget to call parent::__construct()!)
        # or it could be a json encoded object... anything you like
    }
}

Housekeeping

The module comes with a cron job that cleans the queue of any messages that were not created or updated in the last 2 months., _(*10)

If you want to make changes to the clearing criteria, override the Creode\MessageQueue\Cron\CleanQueue class and adjust the cleanupMessages method. If you just want to override the threshold then you can leave the cleanupMessages method alone and simply override the DATE_THRESHOLD class constant., _(*11)