Create a list of dispatched events in Magento2

Mar 23, 2016 Magento

Magento2 has reduced the use of events. I guess the Magento plug-ins are more powerful. Today I would like to show, how to create a list of all dispatched events after visiting the product page for example. I have written a similar post a few years ago for older Magento versions.

We are searching for all calls of dispatch on an instance of Magento\Framework\Event\Manager. Here for example a bundle of really useful events in the function afterSave of the class Magento\Framework\Model\AbstractModel.

public function afterSave()
{
    $this->cleanModelCache();
    $this->_eventManager->dispatch('model_save_after', ['object' => $this]);
    $this->_eventManager->dispatch('clean_cache_by_tags', ['object' => $this]);
    $this->_eventManager->dispatch($this->_eventPrefix . '_save_after', $this->_getEventData());
    $this->updateStoredData();
    return $this;
}

We will now change the function dispatch of the class Magento\Framework\Event\Manager.

public function dispatch($eventName, array $data = [])
{
    $eventName = mb_strtolower($eventName);
	// START CHANGES
	$eventLogFile = fopen('../var/log/events.log', 'a');
	fwrite($eventLogFile, $eventName . ' => ' . implode(', ', array_keys($data)) . "\n");
	fclose($eventLogFile);
	// END CHANGES
    \Magento\Framework\Profiler::start('EVENT:' . $eventName, ['group' => 'EVENT', 'name' => $eventName]);
    foreach ($this->_eventConfig->getObservers($eventName) as $observerConfig) {
        $event = new \Magento\Framework\Event($data);
        $event->setName($eventName);

        $wrapper = new Observer();
        $wrapper->setData(array_merge(['event' => $event], $data));

        \Magento\Framework\Profiler::start('OBSERVER:' . $observerConfig['name']);
        $this->_invoker->dispatch($observerConfig, $wrapper);
        \Magento\Framework\Profiler::stop('OBSERVER:' . $observerConfig['name']);
    }
    \Magento\Framework\Profiler::stop('EVENT:' . $eventName);
}

After that we visit a product page and the file var/log/events.log should be generated.

Eventlist of a product page

Here for example a list of all dispatched events with the given data after visiting a product page.