拼合树结构输出html列表（php）

Question

我有一个有序的树（节点的输出顺序正确）。每个节点都有name，depth和parent_id属性。我试图输出一个嵌套列表，以便我可以直观地看到结构。我在提出正确的方面遇到了一些麻烦。解决这个问题的最佳方法是什么？我是否需要更改数据结构和/或逻辑？

这是数据：

array(24) {
  [5]=>
  array(3) {
    ["depth"]=>
    int(0)
    ["name"]=>
    string(16) "Basketball Sport"
    ["parent_id"]=>
    NULL
  }
  [3]=>
  array(3) {
    ["depth"]=>
    int(1)
    ["name"]=>
    string(16) "Basketball Shoes"
    ["parent_id"]=>
    string(1) "5"
  }
  [2]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(6) "Jordon"
    ["parent_id"]=>
    string(1) "3"
  }
  [4]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(6) "Lebron"
    ["parent_id"]=>
    string(1) "3"
  }
  [7]=>
  array(3) {
    ["depth"]=>
    int(1)
    ["name"]=>
    string(17) "Basketball Shorts"
    ["parent_id"]=>
    string(1) "5"
  }
  [8]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(22) "Long Basketball Shorts"
    ["parent_id"]=>
    string(1) "7"
  }
  [9]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(23) "Short Basketball Shorts"
    ["parent_id"]=>
    string(1) "7"
  }
  [10]=>
  array(3) {
    ["depth"]=>
    int(0)
    ["name"]=>
    string(10) "Golf Sport"
    ["parent_id"]=>
    NULL
  }
  [12]=>
  array(3) {
    ["depth"]=>
    int(1)
    ["name"]=>
    string(4) "Bags"
    ["parent_id"]=>
    string(2) "10"
  }
  [13]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(9) "Nike Bags"
    ["parent_id"]=>
    string(2) "12"
  }
  [11]=>
  array(3) {
    ["depth"]=>
    int(1)
    ["name"]=>
    string(5) "Clubs"
    ["parent_id"]=>
    string(2) "10"
  }
  [14]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(10) "Nike Clubs"
    ["parent_id"]=>
    string(2) "11"
  }
  [6]=>
  array(3) {
    ["depth"]=>
    int(0)
    ["name"]=>
    string(12) "Tennis Sport"
    ["parent_id"]=>
    NULL
  }
  [1]=>
  array(3) {
    ["depth"]=>
    int(1)
    ["name"]=>
    string(8) "Racquets"
    ["parent_id"]=>
    string(1) "6"
  }
  [22]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(4) "Head"
    ["parent_id"]=>
    string(1) "1"
  }
  [24]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(6) "Prince"
    ["parent_id"]=>
    string(1) "1"
  }
  [23]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(6) "Wilson"
    ["parent_id"]=>
    string(1) "1"
  }
  [15]=>
  array(3) {
    ["depth"]=>
    int(1)
    ["name"]=>
    string(12) "Tennis Shoes"
    ["parent_id"]=>
    string(1) "6"
  }
  [16]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(17) "Mens Tennis Shoes"
    ["parent_id"]=>
    string(2) "15"
  }
  [19]=>
  array(3) {
    ["depth"]=>
    int(3)
    ["name"]=>
    string(23) "Cheap Mens Tennis Shoes"
    ["parent_id"]=>
    string(2) "16"
  }
  [18]=>
  array(3) {
    ["depth"]=>
    int(3)
    ["name"]=>
    string(27) "Expensive Mens Tennis Shoes"
    ["parent_id"]=>
    string(2) "16"
  }
  [17]=>
  array(3) {
    ["depth"]=>
    int(2)
    ["name"]=>
    string(19) "Womens Tennis Shoes"
    ["parent_id"]=>
    string(2) "15"
  }
  [20]=>
  array(3) {
    ["depth"]=>
    int(3)
    ["name"]=>
    string(28) "Women Practical Tennis Shoes"
    ["parent_id"]=>
    string(2) "17"
  }
  [21]=>
  array(3) {
    ["depth"]=>
    int(3)
    ["name"]=>
    string(26) "Women Stylish Tennis Shoes"
    ["parent_id"]=>
    string(2) "17"
  }
}

列表输出（注意它如何不断深化）：

CODE：

<ul id="category_root">
        <?php 
        $current_depth = 0;

        foreach($categories as $category_id => $category_info)  
        {
            //Same level
            if ($current_depth == $category_info['depth'])
            {
                // echo 'SAME LEVEL'. $category_info['name'].'<br />';
                echo '<li class="same_level">'.$category_info['name'].'</li>';
            }//Sub category
            elseif ($current_depth < $category_info['depth'])
            {
                echo '<ul><li class="subcat_start">'.$category_info['name'];
            }//End sub category
            elseif($current_depth > $category_info['depth'])
            {
                echo '</li></ul>'.$category_info['name'];
            }


            $current_depth = $category_info['depth'];
        }
        ?>
</ul>