Get all 3rd level categories

Question

is there any chance how to get ALL third level categories available? I have searched whole internet and found only getting categories based on parent category but it doesnt return whole store 3rd level categories because in this situation I dont have one parent category, since I need all of them. Also I have found a lot of solutions using objectManager but I know you should avoid using it.

P.S. If you have an solution, it would be really nice to do it correctly - using CategoryRepository and definitely not using objectManager.

Thanks a lot!

Answer 1

Note that there is no CategoryRepository, but there is a CategoryListInterface that you can use in conjunction with a SearchCriteriaInterface

Something like this should work:

    /** @var \Magento\Catalog\Api\CategoryListInterface */
protected $categoryList;

/** @var \Magento\Framework\Api\SearchCriteriaBuilder */
protected $searchCriteriaBuilder;

/**
 * Constructor
 *
 * @param \Magento\Backend\App\Action\Context $context
 * @param \Magento\Framework\View\Result\PageFactory $resultPageFactory
 */
public function __construct(
    \Magento\Backend\App\Action\Context $context,
    \Magento\Catalog\Api\CategoryListInterface $categoryList,
    \Magento\Framework\Api\SearchCriteriaBuilder $searchCriteriaBuilder
) {
     parent::__construct($context);
     $this->categoryList = $categoryList;
     $this->searchCriteriaBuilder = $searchCriteriaBuilder;
}

/**
 * Redirect back to cadmart core
 *
 * @return \Magento\Framework\View\Result\Page
 */
public function execute(){
    $criteria = $this->searchCriteriaBuilder->addFilter('level', 3);
    $searchResult = $this->categoryList->getList($criteria);
    foreach ($searchResult->getItems() as $category) {
        echo($category->getName());
    }
}