Mryntu

How can I retrieve a product collection by a root category and from all its subcategories?

Eg:

Root Category (2 products)

• 
  Subcategory 1 (2 products)


• 
  Subcategory 2 (3 products)

So I want to retrieve all 7 products in the collection.

You can use like this:

/** MagentoCatalogApiCategoryRepositoryInterface */
protected $categoryRepository;

/** MagentoCatalogModelResourceModelProductCollectionFactory */
protected $productCollectionFactory;

public function getAllProductOfSubcategories($categoryId, $storeId = null) 

 /** @var $result MagentoCatalogModelResourceModelProductCollection */
 $result = $this->productCollectionFactory->create();

 //get category at $storeId 
 try 
 $category = $this->categoryRepository->get($categoryId, $storeId);
 catch (MagentoFrameworkExceptionNoSuchEntityException $noSuchEntityException) 
 return null;
 

 return $result->addCategoryFilter($category);

*Note: Your category must Enable Anchor

*Note: run php bin/magento indexer:reindex just for make sure

Code for your class file:

protected $_categoryHelper;
protected $_categoryRepository;

public function __construct(
 MagentoCatalogHelperCategory $categoryHelper,
 MagentoCatalogModelCategoryRepository $categoryRepository,
 array $data = []
)

 $this->_categoryHelper = $categoryHelper;
 $this->_categoryCategoryRepository = $categoryRepository; 
 parent::__construct($context, $data);


public function getStoreCategories() 

 return $this->_categoryHelper->getStoreCategories();


public function getCategory($categoryId)

 return $this->_categoryRepository->get($categoryId);

Code for your template file:

$categories = $block->getStoreCategories();
foreach ($categories as $category) 
 echo $category->getName();
 echo ' ( ' . $category->getProductCount() . ' )';

 $subCategories = $block->getCategory($category->getId());
 foreach ($subCategories as $subCategory) 
 echo $subCategory->getName();
 echo ' ( ' . $subCategory->getProductCount() . ' )';
 

Source: Magento 2: Get parent category, children categories & product count

I solved it as below,

protected $_category;
protected $_productCollection;

/** You should provide your root category here, and it will return comma seperated sub category list */
public function getChildren($categoryId = false)

 if ($this->_category) 
 return $this->_category->getChildren();
 else 
 return $this->getCategory($categoryId)->getChildren();
 
 

protected function _getProductCollection()

 $childListStr = $this->getChildren( 2 ); // Provide the root category ID
 $childList = explode( ",", $childListStr );
 $catToLoad = array();

 foreach( $childList as $item )
 array_push( $catToLoad, $item );
 

 if ($this->_productCollection === null) 
 $layer = $this->getLayer();
 $this->_productCollection = $layer->getProductCollection(); 
 

 $this->_productCollection->addCategoriesFilter(['in' => $catToLoad ]); 
 return $this->_productCollection;

Hi I have another way to get product collection from root category... check it out.. I hope this help

public function __construct(
 MagentoCatalogModelLayerCategory $categoryLayer 
)
 $this->_categoryLayer = $categoryLayer;


public function getProductCollection($category)
 return $this->_categoryLayer->setCurrentCategory($category)->getProductCollection();

Try this

 $category = Mage::getModel('catalog/category')->load(2);
 $children = Mage::getModel('catalog/category')->getCollection()->setStoreId(Mage::app()->getStore()->getId());
 $children->addAttributeToSelect('*')
 ->addAttributeToFilter('parent_id', $category->getId())
 ->addAttributeToFilter('is_active', 1)
 ->addAttributeToSort('position');
foreach($children as $child)


 $category=Mage::getModel('catalog/category')->load($child->entity_id);