Advanced Search

Create tree structure in PHP

/ Published in: PHP
Save to your folder(s)
This snippet demonstrates how to build tree structure with PHP.

Expand | Embed | Plain Text

Copy this code and paste it in your HTML 
  1. <?php
  2. class Node
  3. {
  4.     public $depth = 0;          //for printing
  5.     public $parentNode = null;  //reference to parent node
  6.     public $text = '';          //display text
  7.     public $children = array(); //children node(s)
  8.  
  9.     function __construct($params = null)
  10.     {
  11.         foreach($params as $key=>$val)
  12.             $this->$key = $val;
  13.         if (isset($this->parentNode))
  14.             $this->parentNode->addChild($this);
  15.     }
  16.     public function addChild(Node $node)
  17.     {
  18.         $this->children[] = $node;
  19.     }
  20. }
  21. //-------------- end of class Node
  22. class Tree
  23. {
  24.     public $root = null;
  25.  
  26.     function __construct($maxLevel = 3)
  27.     {
  28.         $this->buildTree($maxLevel);
  29.     }
  30.  
  31.     public function buildTree($maxLevel = 3)
  32.     {
  33.         $this->root = new Node(array('text'=>'Root'));
  34.         $this->populateChildren($this->root, 1, $maxLevel);
  35.     }
  36.  
  37.     public function printNodes()
  38.     {
  39.         $this->printChildren($this->root);
  40.     }
  41.  
  42.     private function printChildren(Node $node)
  43.     {
  44.         $N = $node->depth * 4;
  45.         for ($idx = 0; $idx < $N; $idx++)
  46.             echo '&nbsp;';
  47.  
  48.         echo $node->text . "<br />\n";
  49.         foreach($node->children as $child)
  50.             $this->printChildren($child);
  51.     }
  52.  
  53.     private function populateChildren(Node $pnode, $level, $maxLevel)
  54.     {
  55.         //demonstrate how to populate tree's node
  56.         if ($level <= $maxLevel)
  57.         {
  58.             for($idx = 0; $idx < $level; $idx++)
  59.             {
  60.                 $child = new Node(array(
  61.                     'parentNode'=> $pnode, 
  62.                     'text' => "$level::Node[$idx]", 
  63.                     'depth'=>$level)
  64.                 );
  65.                 $this->populateChildren($child, $level + 1, $maxLevel);
  66.             }
  67.         }
  68.     }	
  69. }
  70. //-------------- end of class Tree
  71.  
  72. //test displaying tree
  73. $tree = new Tree(4);
  74. $tree->printNodes();

Report this snippet


Comments

RSS Icon Subscribe to comments

You need to login to post a comment.