Admin Product Grid Rewrite is not working in Magento 2

[Sanjay Jethva]

Hello Friends,

I am trying to rewrite Admin Product Grid Block via below code as i need to rewrite method _prepareMassaction() but rewrite is not working.

I have place a below code in

Magento/Demo/etc/adminhtml/di.xml

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
	<preference for="Magento\Catalog\Block\Adminhtml\Product\Grid" type="Magento\Demo\Block\Adminhtml\Product\Grid" />    
</config>

and

Magento\Demo\Block\Adminhtml\Product\Grid.php

namespace Magento\Demo\Block\Adminhtml\Product;
class Grid extends \Magento\Catalog\Block\Adminhtml\Product\Grid
{
	protected $_logger;
	protected $_eventManager;
	public function __construct(\Psr\Log\LoggerInterface $logger, \Magento\Framework\Event\ManagerInterface $eventManager,)
	{
		$this->_objectManager = $objectManager;
		$this->_logger = $logger;
		$this->_eventManager  = $eventManager;
		//parent::__construct($data);
	}
	
	protected function _prepareMassaction()
    {
		parent::_prepareMassaction();
		$this->_eventManager->dispatch('product_grid_massaction_event', ['grid' => $this]);
	}
}

I need to add custom Mass Actions by using above method.
Thanks for you answer in advance.

[Dmitry_Fedyuk]

You should not rewrite the admin product grid, because it will break (and will be broken by) all the other extensions, which try to do the same.

Use the plugins instead: http://devdocs.magento.com/guides/v2.0/extension-dev-guide/plugins.html 

[Sanjay Jethva]

Hello @Dmitry_Fedyuk

Thanks for your answer.

I have used the below code in di.xml file.

<type name="Magento\Catalog\Block\Adminhtml\Product\Grid">
<plugin name="magento-catalog-adminhtml-product-grid-plugin" type="Magento\Demo\Block\Adminhtml\Product\Grid" sortOrder="10"/>
</type>

I want to rewrite  protected function _prepareMassaction() of

Magento\Catalog\Block\Adminhtml\Product\Grid

Please tell me what i will use to rewrite above method in

Magento\Demo\Block\Adminhtml\Product\Grid

Let me know as above class is protected.

[Dmitry_Fedyuk]

It impossible to plug-in to a protected method, but the method fires an event, and you can handle it.

How to add a custom massaction to the Magento 2 backend product grid? https://mage2.pro/t/997

The events is another good way to add a new functionality because you are not breaking another extensions.

[MageMod_Ext]

Hello @Dmitry_Fedyuk

Can you please give me one example of https://mage2.pro/t/topic/997 as how can i use it to my extension?

Thanks in advnace.