Magento 2 - How to get category name and category tree for product or for category id?

Question

Magento 2.2.7

I have to output category name and "tree" or path for product. For instance if my product is in category Lg775 my output should be: Hardware/Motherboards/Intel/Lg775

so far I have this code that gives me category ID:

 //Load the product categories
 $categories = $product_data->getCategoryIds();
 //Select the last category in the list
 $categoryId = end($categories); 

Thank you all Magento experts for all the help so far! I really appreciate it :)

---

UPDATE - Solved

So I used the answer I checked however I had to modify the code so here is my code how to get full category path for "categoryID"

<?php

namespace Vendor\Module\Helper;


class CategoryTree {

    /**
     * @var \Magento\Store\Model\StoreManagerInterface
     */
    private $storeManager;

    /**
     * @var \Magento\Catalog\Api\CategoryRepositoryInterface
     */
    private $categoryRepository;

    /**
     * @var \Magento\Catalog\Model\ResourceModel\Category\Tree
     */
    private $tree;

    public function __construct(
        \Magento\Catalog\Api\CategoryRepositoryInterface $categoryRepository,
        \Magento\Catalog\Model\ResourceModel\Category\Tree $tree,
        \Magento\Store\Model\StoreManagerInterface $storeManager) {
       $this->tree = $tree;
       $this->categoryRepository = $categoryRepository;
       $this->storeManager = $storeManager;
    } // end of function __construct


    public function getTreeByCategoryId($categoryId)
    {
        $storeId = $this->storeManager->getStore()->getId();
        $category = $this->categoryRepository->get($categoryId, $storeId);
        $categoryTree = $this->tree->setStoreId($storeId)->loadBreadcrumbsArray($category->getPath());

        $categoryTreepath = array();
        foreach($categoryTree as $eachCategory){
            echo $eachCategory['name'];
            $categoryTreepath[] = $eachCategory['name'];
        }
      $categoryTree = implode(" &gt; ",$categoryTreepath);
      return $categoryTree;
    } // end of function getTreeByCategoryId

} // end of class

later I called that class like this:

      $categoryObject=\Magento\Framework\App\ObjectManager::getInstance();
      $category=$categoryObject->create('Vendor\Module\Helper\CategoryTree');
      $categoryTreepath=$category->getTreeByCategoryId($categoryId);
      var_dump($categoryTreepath);

The result was just what I needed :) Thank you all!

Answer 1

If you want to get a particular category tree you have to use below method

Magento\Catalog\Model\ResourceModel\Category\Tree::loadBreadcrumbsArray($path, $addCollectionData = true, $withRootNode = false);

As per this method definition, you have to provide category path $path, of your category instead category ID.

So, first, you have to get category path by category id then load and after that get category tree by tree.

Code:

<?php

namespace StackExchange\Magento\Model;


class CategoryTree {

    /**
     * @var \Magento\Store\Model\StoreManagerInterface
     */
    private $storeManager;

    /**
     * @var \Magento\Catalog\Api\CategoryRepositoryInterface
     */
    private $categoryRepository;

    /**
     * @var \Magento\Catalog\Model\ResourceModel\Category\Tree
     */
    private $tree;

    public function __construct(
        \Magento\Catalog\Api\CategoryRepositoryInterface $categoryRepository,
        \Magento\Catalog\Model\ResourceModel\Category\Tree   $tree ,
        \Magento\Store\Model\StoreManagerInterface $storeManager    
   ) {

       $this->tree = $tree;
       $this->categoryRepository = $categoryRepository;
       $this->storeManager = $storeManager;
    }
    public function getTreeByCategoryId()
    {
        $storeId = $this->storeManager->getStore()->getId();
        $categoryId = 45;
        $category = $this->categoryRepository->get($categoryId, $storeId);
        $categoryTree = $this->tree->setStoreId($storeId)->loadBreadcrumbsArray($category->getPath());

        $categoryTreepath = '';
        foreach($categoryTree as $eachCategory){
             echo $category['name'];
            echo '<pre>';
            print_r($eachCategory);
           $categoryTreepath = $categoryTreepath. '/'.$category['name'];
        }
    }
}

Answer 2

You can get breadcrumb of the category by category Id using Magento\Catalog\Model\CategoryFactory as follows:

...
protected $_categoryFactory;
...
public function __construct(
    \Magento\Catalog\Model\CategoryFactory $categoryFactory
) {
    $this->_categoryFactory = $categoryFactory;
}

public function execute() {
    //Load the product categories
    $categories = $product_data->getCategoryIds();
    //Select the last category in the list
    $categoryId = end($categories);
    $category = $this->_categoryFactory->create()->load($categoryId);
    //Parent Categories
    $parentCategories = $category->getParentCategories();

    foreach ($parentCategories as $cat) {
        echo $cat->getId() . ": " . $cat->getName() . " :: " . $cat->getUrl() . "<br />";
    }
}

I hope this may helpful to anyone!