Retrieve currently selected category children categories.

@return \Magento\Catalog\Model\ResourceModel\Category\Collection|\Magento\Catalog\Model\Category[]
439642
protected function getChildrenCategories()
    {
        if ($this->childrenCategories === null) {
            $currentCategory = $this->dataProvider->getCategory();
            $this->childrenCategories = $currentCategory->getChildrenCategories();
        }

        return $this->childrenCategories;
    }
260704
public function getChildren()
    {
        if (isset($this->relations['children'])) {
            return $this->relations['children'];
        }

        $children = $this->getAttribute('children');

        return $children === null ? [] : $children;
    }
24993
public function children()
    {
        return $this->subChildren()
            ->with(['children' => function ($query) {
                $query->select(get_class($this)::getFillableFields());
            }])
            ->select(get_class($this)::getFillableFields());
    }
935575
public function getChildren()
    {
        $children = [];
        if ($this->entity->getChildren()) {
            foreach ($this->entity->getChildren() as $child) {
                $children[] = new self($child, $this->locale);
            }
        }

        return $children;
    }
993418
public function get_categories_with_fields() : array {
        if ($this->categories === null) {
            $this->categories = api::get_categories_with_fields($this->get_component(), $this->get_area(), $this->get_itemid());
        }
        $handler = $this;
        array_walk($this->categories, function(category_controller $c) use ($handler) {
            $c->set_handler($handler);
        });
        return $this->categories;
    }
1177571
private function getAttributeKeys()
    {
        if (!isset($this->attributeKeys)) {
            $this->attributeKeys = $this->category->getList();
        }

        return $this->attributeKeys;
    }
166731
public function getCategoryfromPage()
    {
        $this->logger->debug('Category:getCategoryfromPage');
        if (!$this->setIdentifier('', 's')) {
            return [];
        }
        $this->setGeneratorCategories();
        return $this->getCategoryinfoResponse();
    }
882016
public function getCategories()
    {
        $categoryEntities = $this->entity->getCategories();

        $categories = [];
        if ($categoryEntities) {
            foreach ($categoryEntities as $categoryEntity) {
                $categories[] = new Category($categoryEntity, $this->locale);
            }
        }

        return $categories;
    }
1062735
public function get_parent_category() {
        if ($this->is_category_item() or $this->is_course_item()) {
            return $this->get_item_category();

        } else {
            return grade_category::fetch(array('id'=>$this->categoryid));
        }
    }
61351
public function children()
    {
        return $this->menu->items->filter(function ($item) {
            return $item->hasParent() && $item->parent->name == $this->name;
        });
    }
104437
public function getParentCategory()
    {
        $parentCategory = null;
        $currentCategory = $this->getCurrentCategory();
        if (null !== $currentCategory) {
            $parentCategoryId = $currentCategory->getParentId();
            $parentCategory = $this->_categoryRepository->get(
                $parentCategoryId,
                $this->_storeManager->getStore()->getId()
            );
            if (null !== $parentCategory && 1 >= $parentCategory->getLevel()) {
                $parentCategory = null;
            }
        }
        return $parentCategory;
    }
544507
public function parentCategoriesAreActive()
    {
        $treeIsActive = true;
        $parentCategoryList = $this->getParentCategories();
        while ($category = $parentCategoryList->Next()) {
            if (false === $category->fieldActive) {
                $treeIsActive = false;
                break;
            }
        }

        return $treeIsActive;
    }
317541
public static function &GetDefaultCategory()
    {
        static $oCategory;
        if (!$oCategory) {
            $oRootCategories = &TdbShopCategoryList::GetChildCategories();
            if ($oRootCategories->Length() > 0) {
                $oCategory = &$oRootCategories->Current();
            }
        }

        return $oCategory;
    }
314582
public function getChildren()
    {
        $children = new ArrayCollection();
        if ($this->reference) {
            $children->add($this->reference);
        }

        return $children;
    }
51573
public function get_parent_category() {
        if (!empty($this->parent)) {
            $parent_category = new grade_category(array('id' => $this->parent));
            return $parent_category;
        } else {
            return null;
        }
    }
507367
public function getParents()
    {
        $parents = $this()->beColl();

        $category = $this;
        while ($parent = $category->getParent()->find()) {
            $parents[] = $category = $parent;
        }

        return $parents;
    }
625178
@Override
    public List<Category> getCategories() {
        return categories == null ? (categories = new ArrayList<Category>()) : categories;
    }