Override constructor of vender/magento/module_caltalog/block/ Block in magento 2

Question

I am trying to get product list from specific category id. i am using magento 2.2.1 version.

below are my code of Block File : view.php i want to override this file from vender.

Here is my custom module :

app\code\Narola\Magentocatalog\Block\Category\View.php

namespace Narola\Magentocatalog\Block\Category;
class View extends \Magento\Catalog\Block\Category\View
{
 protected $_productCollectionFactory;
 protected $_categoryFactory;
 public function __construct(
 \Magento\Framework\View\Element\Template\Context $context,
 \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $productCollectionFactory,
 \Magento\Catalog\Model\CategoryFactory $categoryFactory,
 array $data = []
 ) {
 $this->_categoryFactory = $categoryFactory;
 $this->_productCollectionFactory = $productCollectionFactory;
 parent::__construct($context, $data);
}
public function getSubcategory($catId) 
{
 $objectManagerr = \Magento\Framework\App\ObjectManager::getInstance();
 $categoryFactory = $objectManagerr->create('Magento\Catalog\Model\ResourceModel\Category\CollectionFactory');
 $collection = $categoryFactory->create()
 ->addFieldToFilter('parent_id', $catId) 
 ->addAttributeToSelect('*');
 return $collection;
}
public function getSubcategory_product($sub_catid){
 $category = $this->_categoryFactory->create()->load($categoryId);
 $collection = $this->_productCollectionFactory->create();
 $collection->addAttributeToSelect('*');
 $collection->addCategoryFilter($category);
 $collection->addAttributeToFilter('visibility', \Magento\Catalog\Model\Product\Visibility::VISIBILITY_BOTH);
 $collection->addAttributeToFilter('status',\Magento\Catalog\Model\Product\Attribute\Source\Status::STATUS_ENABLED);
 return $collection;
} 
}

==============================

Here when i add constructor i am getting below error.

---

Fatal error: Uncaught TypeError: Argument 2 passed to Magento\Catalog\Block\Category\View::__construct() must be an instance of Magento\Catalog\Model\Layer\Resolver, array given, called in C:\wamp64\www\magento_221\app\code\Narola\Magentocatalog\Block\Category\View.php on line 18 and defined in C:\wamp64\www\magento_221\vendor\magento\module-catalog\Block\Category\View.php on line 45

If any one has solution regarding this then please provide me.

Answer 1

Your constructor has to be like

\Magento\Framework\View\Element\Template\Context $context,
\Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $productCollectionFactory,
\Magento\Catalog\Model\CategoryFactory $categoryFactory,
\Magento\Framework\View\Element\Template\Context $context,
\Magento\Catalog\Model\Layer\Resolver $layerResolver,
\Magento\Framework\Registry $registry,
\Magento\Catalog\Helper\Category $categoryHelper,
array $data = []

and call the parent function like

parent::__construct($context, $layerResolver, $layerResolver, $categoryHelper, $data);

• TheMask: One more question if i want to get specific category product list then what i need to do? i mean i don't want to display product of subcategory then?
• Dhaduk Mitesh: How to add __construct in ResourceModel.

Answer 2

You must use this code:

<?php
namespace Narola\Magentocatalog\Block\Category;
class View extends \Magento\Catalog\Block\Category\View
{
 protected $_productCollectionFactory;
 protected $_categoryFactory;
 /**
 * Core registry
 *
 * @var \Magento\Framework\Registry
 */
 protected $_coreRegistry = null;
 /**
 * Catalog layer
 *
 * @var \Magento\Catalog\Model\Layer
 */
 protected $_catalogLayer;
 /**
 * @var \Magento\Catalog\Helper\Category
 */
 protected $_categoryHelper;
 /**
 * @param \Magento\Framework\View\Element\Template\Context $context
 * @param \Magento\Catalog\Model\Layer\Resolver $layerResolver
 * @param \Magento\Framework\Registry $registry
 * @param \Magento\Catalog\Helper\Category $categoryHelper
 * @param array $data
 */
 public function __construct(
 \Magento\Framework\View\Element\Template\Context $context,
 \Magento\Catalog\Model\Layer\Resolver $layerResolver,
 \Magento\Framework\Registry $registry,
 \Magento\Catalog\Helper\Category $categoryHelper,
 \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $productCollectionFactory,
 \Magento\Catalog\Model\CategoryFactory $categoryFactory,
 array $data = []
 ) {
 $this->_categoryFactory = $categoryFactory;
 $this->_productCollectionFactory = $productCollectionFactory;
 $this->_categoryHelper = $categoryHelper;
 $this->_catalogLayer = $layerResolver->get();
 $this->_coreRegistry = $registry;
 parent::__construct($context, $layerResolver, $registry, $categoryHelper, $data);
 }
 public function getSubcategory($catId) 
 {
 $objectManagerr = \Magento\Framework\App\ObjectManager::getInstance();
 $categoryFactory = $objectManagerr->create('Magento\Catalog\Model\ResourceModel\Category\CollectionFactory');
 $collection = $categoryFactory->create()
 ->addFieldToFilter('parent_id', $catId) 
 ->addAttributeToSelect('*');
 return $collection;
 }
 public function getSubcategory_product($sub_catid){
 $category = $this->_categoryFactory->create()->load($categoryId);
 $collection = $this->_productCollectionFactory->create();
 $collection->addAttributeToSelect('*');
 $collection->addCategoryFilter($category);
 $collection->addAttributeToFilter('visibility', \Magento\Catalog\Model\Product\Visibility::VISIBILITY_BOTH);
 $collection->addAttributeToFilter('status',\Magento\Catalog\Model\Product\Attribute\Source\Status::STATUS_ENABLED);
 return $collection;
 } 
}

The parameters, that you are passing in the constructor doesn't make it compatible with the parent's constructor as you are not passing all of them.