How to Get Product Collection by Category ID in Magento 2

Regarding the fast development of Magento, the product collection is becoming increasingly important. This is because in various project, a product collection is usually required in different filters and requirements. Therefore, in today article, I will show you the steps which could help you get product collection by category in Magento 2.

How to get Product Collection by Category ID

• Step 1: Create Products.php block
• Step 2: Insert in phtml file
• Step 3: Flush Cache & Test result

Step 1: Create Products.php block

In order to get the product collection by category ID, the first thing you would have to do is creating Products.php block. Follow this path: Mageplaza/HelloWorld/Block/Products.php

<?php
namespace Mageplaza\HelloWorld\Block;
class Products extends \Magento\Framework\View\Element\Template
{    
  
     /**
     * @var \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory
     */
    protected $_productCollectionFactory;
  
    public function __construct(
        \Magento\Backend\Block\Template\Context $context,        
        \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $productCollectionFactory
    )
    {    
        $this->_productCollectionFactory = $productCollectionFactory;
        parent::__construct($context);
    }
    
    
    public function getProductCollectionByCategories($ids)
    {
        $collection = $this->_productCollectionFactory->create();
        $collection->addAttributeToSelect('*');
        $collection->addCategoriesFilter(['in' => ids]);
        return $collection;
    }
}

• Here, $ids is an array, which include category ids.
• $_productCollectionFactory is an object of product collection factory which is used to get collection of product model.
• addCategoriesFilter function to apply category filter.
• $collection returns a collection of products which are assigned in given categories.

Step 2: Insert in phtml file

After the above step, you will have a collection in your block, now to get the Product collection in the block, follow the below snippet: Mageplaza/HelloWorld/view/frontend/templates/list.phtml

$ids = [1,2,3];
$categoryProducts = $block->getProductCollectionByCategories($ids);
foreach ($categoryProducts as $product) {
    echo $product->getName() . ' - ' . $product->getProductUrl() . '<br />';
}

Step 3: Flush Cache & Test result

Now, let’s flush cache and test result.

Conclusion

Above are the three steps, which could help you get product collection by Category ID in Magento 2. I hope this post is helpful for you when obtaining product collection.