Error while listing products of a particular category

Question

This is my block

 <?php 
namespace Xlabs\Ajaxscroll\Block\Product;

class Ajaxscroll extends \Magento\CatalogWidget\Block\Product\ProductsList 
{
    protected $productCollectionFactory;
    protected $_categoryFactory;

    public function __construct(
            \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $productCollectionFactory,
            \Magento\Catalog\Model\CategoryFactory $categoryFactory,
            array $data = []
        ){
        $this->productCollectionFactory = $productCollectionFactory;
        $this->_categoryFactory = $categoryFactory;

        }

    public function getProductList(){

        $categoryId = 12;
        $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;
    }




}

Blockquote

and i am getting the error

Fatal error: Uncaught Error: Call to a member function dispatch() on null in /var/www/html/sample221/vendor/magento/framework/View/Element/AbstractBlock.php:652 Stack trace: #0 /var/www/html/sample221/generated/code/Techievolve/Ajaxscroll/Block/Product/Ajaxscroll/Interceptor.php(830): Magento\Framework\View\Element\AbstractBlock->toHtml() #1 /var/www/html/sample221/vendor/magento/framework/View/Layout.php(558): Techievolve\Ajaxscroll\Block\Product\Ajaxscroll\Interceptor->toHtml() #2 /var/www/html/sample221/vendor/magento/framework/View/Layout.php(534): Magento\Framework\View\Layout->_renderBlock('Ajaxscroll_bloc...') #3 /var/www/html/sample221/generated/code/Magento/Framework/View/Layout/Interceptor.php(206): Magento\Framework\View\Layout->renderNonCachedElement('Ajaxscroll_bloc...') #4 /var/www/html/sample221/vendor/magento/framework/View/Layout.php(489): Magento\Framework\View\Layout\Interceptor->renderNonCachedElement('Ajaxscroll_bloc...') #5 /var/www/html/sample221/generated/code/Magento/Framework/View/Layout/Intercep in /var/www/html/sample221/vendor/magento/framework/View/Element/AbstractBlock.php on line 652

Answer 1

I have used this code which is working for me. Try this -

<?php
namespace Custom\Homeproducts\Block;

use Magento\Catalog\Api\CategoryRepositoryInterface;

class Homeproducts extends \Magento\Catalog\Block\Product\ListProduct
{
    protected $_collection;

    protected $categoryRepository;

    protected $_resource;

    public function __construct(
            \Magento\Catalog\Block\Product\Context $context, 
            \Magento\Framework\Data\Helper\PostHelper $postDataHelper, 
            \Magento\Catalog\Model\Layer\Resolver $layerResolver, 
            CategoryRepositoryInterface $categoryRepository,
            \Magento\Framework\Url\Helper\Data $urlHelper, 
            \Magento\Catalog\Model\ResourceModel\Product\Collection $collection, 
            \Magento\Framework\App\ResourceConnection $resource,
            array $data = []
    ) {
        $this->categoryRepository = $categoryRepository;
        $this->_collection = $collection;
        $this->_resource = $resource;

        parent::__construct($context, $postDataHelper, $layerResolver, $categoryRepository, $urlHelper, $data);
    }

    public function getProducts() {
        $count = $this->getProductCount();                       
        $category_id = $this->getData("category_id");
        $collection = clone $this->_collection;
        //$collection->clear()->getSelect()->reset(\Magento\Framework\DB\Select::WHERE)->reset(\Magento\Framework\DB\Select::ORDER)->reset(\Magento\Framework\DB\Select::LIMIT_COUNT)->reset(\Magento\Framework\DB\Select::LIMIT_OFFSET)->reset(\Magento\Framework\DB\Select::GROUP);

        if(!$category_id) {
            $category_id = $this->_storeManager->getStore()->getRootCategoryId();
        }
        $category = $this->categoryRepository->get($category_id);
        if(isset($category) && $category) {
            $collection->addMinimalPrice()
                ->addFinalPrice()
                ->addTaxPercents()
                ->addAttributeToSelect('name')
                ->addAttributeToSelect('image')
                ->addAttributeToSelect('small_image')
                ->addAttributeToSelect('thumbnail')
                ->addAttributeToSelect($this->_catalogConfig->getProductAttributes())
                ->addUrlRewrite()
                ->addCategoryFilter($category);
        } else {
            $collection->addMinimalPrice()
                ->addFinalPrice()
                ->addTaxPercents()
                ->addAttributeToSelect('name')
                ->addAttributeToSelect('image')
                ->addAttributeToSelect('small_image')
                ->addAttributeToSelect('thumbnail')
                ->addAttributeToSelect($this->_catalogConfig->getProductAttributes())
                ->addUrlRewrite();
        }

        $collection->addAttributeToFilter('status', array('eq' => 1));
        $collection->getSelect()
            ->order('rand()')
            ->limit($count);

        return $collection;
    }

    public function getLoadedProductCollection() {
        return $this->getProducts();
    }

    public function getProductCount() {
        $limit = $this->getData("product_count");
        if(!$limit)
            $limit = 10;
        return $limit;
    }

}