woocommerce build categories tree

I have this categories into my wordpress (woocommerce), and I need to build a menù like this using data retrieved from woocommerce api.

What’s an efficient way to build a menù like this? I have tried to inspect wordpress code without figured out.

This API lets me retrieve all product categories.

https://woocommerce.github.io/woocommerce-rest-api-docs/#list-all-product-categories

this is the object obtained from request:

array(5) {
  [0] => object(stdClass)#77 (10) {
    ["id"] => int(15)
    ["name"] => string(13) "Uncategorized"
    ["slug"] => string(13) "uncategorized"
    ["parent"] => int(0)
    ["description"] => string(0) ""
    ["display"] => string(7) "default"
    ["image"] => NULL
    ["menu_order"] => int(0)
    ["count"] => int(0)
    ["_links"] => object(stdClass)#89 (2) {
      ["self"] => array(1) {
        [0] => object(stdClass)#88 (1) {
          ["href"] => string(68) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories/15"
        }
      }
      ["collection"] => array(1) {
        [0] => object(stdClass)#90 (1) {
          ["href"] => string(65) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories"
        }
      }
    }
  }
  [1] => object(stdClass)#91 (10) {
    ["id"] => int(19)
    ["name"] => string(16) "SUB SUB SUB ZERO"
    ["slug"] => string(16) "sub-sub-sub-zero"
    ["parent"] => int(18)
    ["description"] => string(0) ""
    ["display"] => string(7) "default"
    ["image"] => NULL
    ["menu_order"] => int(0)
    ["count"] => int(1)
    ["_links"] => object(stdClass)#93 (3) {
      ["self"] => array(1) {
        [0] => object(stdClass)#92 (1) {
          ["href"] => string(68) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories/19"
        }
      }
      ["collection"] => array(1) {
        [0] => object(stdClass)#94 (1) {
          ["href"] => string(65) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories"
        }
      }
      ["up"] => array(1) {
        [0] => object(stdClass)#95 (1) {
          ["href"] => string(68) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories/18"
        }
      }
    }
  }
  [2] => object(stdClass)#96 (10) {
    ["id"] => int(18)
    ["name"] => string(12) "SUB-SUB ZERO"
    ["slug"] => string(12) "sub-sub-zero"
    ["parent"] => int(17)
    ["description"] => string(4) "ssss"
    ["display"] => string(7) "default"
    ["image"] => NULL
    ["menu_order"] => int(0)
    ["count"] => int(1)
    ["_links"] => object(stdClass)#98 (3) {
      ["self"] => array(1) {
        [0] => object(stdClass)#97 (1) {
          ["href"] => string(68) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories/18"
        }
      }
      ["collection"] => array(1) {
        [0] => object(stdClass)#99 (1) {
          ["href"] => string(65) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories"
        }
      }
      ["up"] => array(1) {
        [0] => object(stdClass)#100 (1) {
          ["href"] => string(68) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories/17"
        }
      }
    }
  }
  [3] => object(stdClass)#101 (10) {
    ["id"] => int(17)
    ["name"] => string(8) "SUB-ZERO"
    ["slug"] => string(8) "sub-zero"
    ["parent"] => int(16)
    ["description"] => string(3) "sub"
    ["display"] => string(7) "default"
    ["image"] => NULL
    ["menu_order"] => int(0)
    ["count"] => int(1)
    ["_links"] => object(stdClass)#103 (3) {
      ["self"] => array(1) {
        [0] => object(stdClass)#102 (1) {
          ["href"] => string(68) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories/17"
        }
      }
      ["collection"] => array(1) {
        [0] => object(stdClass)#104 (1) {
          ["href"] => string(65) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories"
        }
      }
      ["up"] => array(1) {
        [0] => object(stdClass)#105 (1) {
          ["href"] => string(68) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories/16"
        }
      }
    }
  }
  [4] => object(stdClass)#106 (10) {
    ["id"] => int(16)
    ["name"] => string(4) "ZERO"
    ["slug"] => string(8) "zeroslug"
    ["parent"] => int(0)
    ["description"] => string(11) "prova categ"
    ["display"] => string(7) "default"
    ["image"] => NULL
    ["menu_order"] => int(0)
    ["count"] => int(1)
    ["_links"] => object(stdClass)#108 (2) {
      ["self"] => array(1) {
        [0] => object(stdClass)#107 (1) {
          ["href"] => string(68) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories/16"
        }
      }
      ["collection"] => array(1) {
        [0] => object(stdClass)#109 (1) {
          ["href"] => string(65) "https://woocommerce.devzone.com/wp-json/wc/v3/products/categories"
        }
      }
    }
  }
}

Answer

Finally I figured out, using a recursive function:

    private function _categoriaOrder($level = 0) {
        echo "<ul>";
        for($i = 0; $i < count($this->_mycats[$level]); $i++) {
            echo "<li style='list-style-type: none;'><label style="margin-bottom:0;" for="woo_id_categoria_{$this->_mycats[$level][$i]['id']}"><input value="{$this->_mycats[$level][$i]['id']}" id="woo_id_categoria_{$this->_mycats[$level][$i]['id']}" name="woo_id_categoria[]" type="checkbox">&nbsp;<span>" . $this->_mycats[$level][$i]['id'] . " " . $this->_mycats[$level][$i]['name'] . "</span></label>";
            if(array_key_exists($this->_mycats[$level][$i]['id'], $this->_mycats)) {
                $this->_categoriaOrder($this->_mycats[$level][$i]['id']);
            }
            echo "</li>";
        }
        echo "</ul>";
    }

    public function getCategoriaTree(){
        $categorie = $this->woo->getCategoria(); //here is the object with categories from woocommerce

        foreach($categorie as $k => $category){
            $this->_mycats[(int)$category->parent][] = array(
                'id' => $category->id,
                'name' => $category->name,
            );

            $categories_ordered[(int)$category->parent] = $category;
        }

        ob_start();
        $this->_categoriaOrder(); 
        $output = ob_get_contents();
        ob_end_clean();

        return $output;
    }

use the function getCategoriaTree() for retrieve html.

I hope this could help someone, I spent some hours for get it.