How to Get Product Collection by Category ID in Magento 2

Today we’ll introduce a short but useful tutorial on how to get product collection by category ID in Magento 2. This is a quick way to acquire product collection that saves a lot of configuration time for the store admin and customers. That’s why you might see it is required by customers in an online store.

Regarding the fast development of Magento, the product collection is becoming increasingly important. This is because, in various projects, a product collection is usually required in different filters and requirements. Now let get an idea about product collection and how to get it by category ID in Magento 2.

**How to get Product Collection by Category ID in 3 steps: **

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

Now follow the below steps to get things done in a timely manner. You don’t need to change core code.

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.