Magento 2 - Get Subcategories of Specific Parent Category

Question

What I'd like to do is grab all of the child categories of a specific parent category. I'm assuming the best way to do this is by using the parent's ID and of those child categories that are returned, I'd like to grab their child categories as well.

Answer 1

Check below example to list of all subcategories of specific parent category using parent category ID using the repository.

First of all add CategoryRepository in construct:

<?php
    protected $categoryRepository;
    
    public function __construct(
        \Magento\Catalog\Model\CategoryRepository $categoryRepository
    ) {
        $this->categoryRepository = $categoryRepository;
    }
?>

Now you can use the following way:

<?php
    $categoryId = [YOUR_CATEGORY_ID];
    $category = $this->categoryRepository->get($categoryId);
    $subCategories = $category->getChildrenCategories();
    foreach($subCategories as $subCategory) {
        echo $subCategory->getName();

        /* For Sub Categories */
        if($subcategorie->hasChildren()) {
        $childCategoryObj = $this->categoryRepository->get($subCategory->getId());
        $childSubcategories = $childCategoryObj->getChildrenCategories();
        foreach($childSubcategories as $childSubcategory) {
            echo $childSubcategory->getName();
        }
     }
    }
?>

Answer 2

You need to add a dependency to your class \Magento\Catalog\Model\ResourceModel\Category\CollectionFactory.

Like this:

protected $categoryCollectionFactory;
public function __construct(
    ...
    \Magento\Catalog\Model\ResourceModel\Category\CollectionFactory $categoryCollectionFactory,
    ...
) {
    ...
    $this->categoryCollectionFactory = $categoryCollectionFactory;
    ...
}
public function getDescendants($category, $levels = 2)
{
    if ((int)$levels < 1) {
        $levels = 1;
    }
    $collection = $this->categoryCollectionFactory->create()
          ->addPathsFilter($category->getPath().'/') 
          ->addLevelFilter($category->getLevel() + $levels);
    return $collection;
}

now you just need to call the method getDescendants with the $category object as a parameter and the number of levels you need for subcategories (2 in your case).

Answer 3

Always try to use repository. Here is an example.

Inject CategoryRepository by construct

protected $categoryRepository;

public function __construct(
    \Magento\Catalog\Model\CategoryRepository $categoryRepository
) {
    $this->categoryRepository = $categoryRepository;
}

Now you can use following way:

$parent_category_id = 3;
$categoryObj = $this->categoryRepository->get($parent_category_id);
$subcategories = $categoryObj->getChildrenCategories();
foreach($subcategories as $subcategorie) {
    echo '    --> '.$subcategorie->getName().'<br/>';
}

For 2 level child category:

$categoryObj = $this->categoryRepository->get($parent_category_id);
$subcategories = $categoryObj->getChildrenCategories();
foreach($subcategories as $subcategorie) {
    echo '    --> '.$subcategorie->getName().'<br/>';
    if($subcategorie->hasChildren()) {
        $childCategoryObj = $this->categoryRepository->get($subcategorie->getId());
        $childSubcategories = $childCategoryObj->getChildrenCategories();
        foreach($childSubcategories as $childSubcategorie) {
            echo '        --> '.$childSubcategorie->getName().'<br/>';
        }
    }
}

Answer 4

Use below code to get all active child categories of a specific category.

Function getChildCategories($categoryId) gives all child categories. Where $categoryId - is parent category id

<?php
namespace YourModuleName\CategoryLink\Block;

use Magento\Framework\View\Element\Template;
use Magento\Framework\View\Element\Template\Context;
use Magento\Catalog\Model\CategoryFactory;


/**
 * Category link block
 */
class Link extends Template
{
    /**
     * @var Magento\Catalog\Model\CategoryFactory
     */
    protected $_categoryFactory;


    /**
     * 
     * @param Context $context
     * @param array $data
     */
    public function __construct(
        Context $context, 
        CategoryFactory $categoryFactory,
        array $data = []
    ) {
        parent::__construct($context, $data);
        $this->_categoryFactory = $categoryFactory;
      }

    /**
     * Get children categories 
     * 
     * @param $categoryId Parent category id
     * @return Magento\Catalog\Model\ResourceModel\Category\Collection
     */
    public function getChildCategories($categoryId)
    {

        $_category = $this->_categoryFactory->create();

        $category = $_category->load($categoryId);

        //Get category collection
        $collection = $category->getCollection()
                ->addIsActiveFilter()
                ->addOrderField('name')
                ->addIdFilter($category->getChildren());
        return $collection;
    }

} 

$category->getChildren() - This will gives all chid categories ids.

Answer 5

    $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
    $category = $objectManager->get('Magento\Framework\Registry')->registry('current_category');//get current category 
    $catId = $category->getId(); // Parent Category ID
        $subcategory = $objectManager->create('Magento\Catalog\Model\Category')->load($catId);
$subcats = $subcategory->getChildrenCategories();
        $categoryHelper = $this->getCategoryHelper();    
    <div class="category_bg mobile">
            <ul id="main_cat_bg" class="main_cat_bg">
                <?php
                $cat_togg = 0;
                foreach ($subcats as $subcat) {
                    if (!$subcat->getIsActive()) {
                        continue;
                    }
                    $_category = $objectManager->create('Magento\Catalog\Model\Category')->load($subcat->getId());
                    //$_outputhelper = $this->helper('Magento\Catalog\Helper\Output');
                    $helper    = $this->helper('SR\CategoryImage\Helper\Category');
                    $subcaturl = $subcat->getUrl();
                    $imageUrlthum = $helper->getImageUrl($_category->getData('thumbnail'));
                    //$imageUrlthum = resize($_category->getData('thumbnail'),153,153);
                    //$cat_desc = $_category->getCatDescription();
                    $_imgHtml = '';
                    if ($imageUrlthum) {
                        $_imgHtml = '<img src="' . $imageUrlthum. '" />';

                        //$_imgHtml = $_outputhelper->categoryAttribute($_category, $_imgHtml, 'image');
                /* @escapeNotVerified */
                    } 
                    ?>
                    <li>
                        <div class="sub_cat_content_main">
                            <div class="cat_image_text">
                                <a href="<?php echo $subcaturl ?>">
                                    <?php echo $_imgHtml;?>
                                    <!--<div class="desicription_part">-->
                                    <?php //echo $cat_desc; ?>
                                    <!--</div>-->
                                </a>
                               <div class="sub_name_bg">                
                                    <a href="<?php echo $subcaturl ?>">
                                        <?php echo $subcat->getName(); ?>
                                    </a>
                                </div>
                                <!-- Start 3rd Level Chiled Category-->
                                <?php
                                    $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
                                    $object_managertwo = $objectManager->create('Magento\Catalog\Model\Category')->load($subcat->getId());
                                    $subcatslevelthird = $object_managertwo->getChildrenCategories();
                                ?>
                                <?php if ($subcatslevelthird->count() > 0) { ?>
                                <ul class="sub_cat_bg">
                                    <?php
                                    foreach ($subcatslevelthird as $subcatthird) {
                                        $_outputhelper = $this->helper('Magento\Catalog\Helper\Output');
                                        $subcaturl = $subcatthird->getUrl();
                                        ?>
                                        <li class="cat_image_bg">
                                            <a class="level-top" href="<?php //echo $subcaturl ?>">
                                                <span><?php //echo $subcatthird->getName(); ?></span>
                                            </a>
                                            <div class="child_name_bg">
                                                <span><?php echo $subcatthird->getName(); ?></span>
                                            </div>

                                        <!-- Start 4th Level Chiled Category-->
                                        <?php
                                            $_objectManager = \Magento\Framework\App\ObjectManager::getInstance();
                                            $object_managerthree = $_objectManager->create('Magento\Catalog\Model\Category')->load($subcatthird->getId());
                                            $subcatslevel = $object_managerthree->getChildrenCategories();
                                        ?>
                                        <?php if ($subcatslevel->count() > 0){?>
                                        <ul class="chiled_cat_bg">
                                            <?php
                                            foreach ($subcatslevel as $subcatlevel) {
                                                $_outputhelper = $this->helper('Magento\Catalog\Helper\Output');
                                                $subcaturl = $subcatlevel->getUrl();
                                                ?>
                                                <li class="cat_image_bg">
                                                    <a class="level-top" href="<?php echo $subcaturl ?>">
                                                        <span><?php echo $subcatlevel->getName(); ?></span>
                                                    </a>
                                                </li>

                                            <?php } ?>
                                        </ul>
                                        <?php } ?>
                                        <!-- End 4th level Chiled Category-->
                                        </li>
                                    <?php } ?>
                                </ul>
                                <?php } ?>
                                <!-- End 3rd level Chiled Category-->
                            </div>
                        </div>
                    </li>
                <?php } ?>
            </ul>
             <div id="view_more">
                View more
            </div>
        </div>

Answer 6

-> Get all level subcategories from parent category

$categoryId = 58;
allCategories($categoryId);
function allCategories($categoryId) {
    $objectManager =  \Magento\Framework\App\ObjectManager::getInstance();
    $categoryFactory = $objectManager->get('\Magento\Catalog\Model\CategoryFactory');

    // Load category by category ID
    $category = $categoryFactory->create()->load($categoryId);
    echo "<pre>"; print_r($category->getData());

    // Get comma-separated children category ids
    $childrenCategoryIds = $category->getChildren($categoryId);
    echo $childrenCategoryIds;

    //Get all children category ids ids comma-separated
    $allChildrenCategoryIds = $category->getAllChildren(false);
    echo $allChildrenCategoryIds;

    //Get all children category ids as an array
    $allChildrenCategoryIdsArr = $category->getAllChildren(true);
    echo "<pre>"; print_r($allChildrenCategoryIdsArr);

    $allChildCategories = allChildLoop($category);
    echo "<pre>"; print_r($allChildCategories);

}

function allChildLoop($category) {
    $idsArray = $category->getAllChildren(true);
    $objectManager =  \Magento\Framework\App\ObjectManager::getInstance();
    $categoryFactory = $objectManager->get('\Magento\Catalog\Model\CategoryFactory');
    $collection = $categoryFactory->create()->getCollection()->addAttributeToSelect('*')->addAttributeToFilter('is_active', 1)->setOrder('position', 'ASC')->addIdFilter($idsArray);
    $categoryNames = array();
    foreach ($collection as $key => $category) {
        $categoryNames[] = $category->getName();
    }
    return $categoryNames;
}

Answer 7

<?php

    // \Magento\Catalog\Model\CategoryFactory $categoryFactory 
    // \Magento\Catalog\Model\ResourceModel\CategoryFactory $categoryResourceFactory,
    // \Magento\Store\Model\StoreManagerInterface $storeManager,

public function getStoreBasedCategories($storeId)
{

    $category = $this->categoryFactory->create();
    $storeRootCategoryId = $this->storeManager->getStore($storeId)->getRootCategoryId();

    $storeRootCategory = $category->load($storeRootCategoryId);
    $categoryResource = $this->categoryResourceFactory->create();
    $childrenCategories = $categoryResource->getChildren($storeRootCategory, true);

    foreach($childrenCategories as $categoryId) {
        $category = $this->categoryFactory->create();
        $storeCategories[] = $category->load($categoryId);
    }

    return $storeCategories;
}