Objet composite

<?php
class Component
{
 
  // Attributes
  private $basePath; 
  private $name;
  private $parent;
 
  public function __construct($name, CDirectory $parent = null)
  {
    // Debug : echo "constructor Component";
    $this->name = $name;
    $this->parent = $parent;
    if($this->parent != null)
    {
       $this->parent->addChild($this);
       $this->basePath = $this->parent->getPath();
    }
    else
    {
      $this->basePath = '';                   
    }
  }
 
 
  // Getters  
  public function getBasePath() { return $this->basePath; }
  public function getName() { return $this->name; }
  public function getParent() { return $this->parent; }
 
  // Setters
  public function setBasePath($basePath) { $this->basePath = $basePath; }
  public function setName($name) { $this->name = $name; }
  public function setParent(CDirectory $parent) { $this->parent = $parent; }
 
  // Method
  public function getPath() { return $this->getBasePath().'/'.$this->getName(); }
}
 
class CFile extends Component
{
 
  // Attributes
  private $type;
 
 
  public function __construct($name, $type, CDirectory $parent = null)
  {
    // Debug : echo "constructor CFile";
    $this->type = $type;
 
    // Retrieve constructor of Component
    parent::__construct($name, $parent); 
  }
 
  // Getters  
  public function getType() { return $this->type; }
 
  // Setters
  public function setType($type) { $this->type = $type; }
 
  // Methods of Component class
  public function getName() { return parent::getName().'.'.$this->getType();
  public function getPath() { return parent::getPath().'.'.$this->getType(); }
}
 
class CDirectory extends Component
{
 
  // Attributes
  private $childs;
 
  public function __construct($name, CDirectory $parent = null)
  {
    // Debug : echo "constructor CDirectory";
    $this->childs = array();
 
    // Retrieve constructor of Component
    parent::__construct($name, $parent);
  }
 
  // Getters  
  public function getChilds() { return $this->childs; }
 
  // Setters
  public function setChilds($childs) { $this->childs = $childs; }
 
 
  // Methods
  public function addChild(Component $child)
  {
    $child->setParent($this);
    $this->childs[] = $child;
  }
 
  public function showChildsTree($level = 0)
  {
    echo "<br/>".str_repeat('&nbsp;', $level).$this->getName();
    foreach($this->getChilds() as $child)
    {
      if($child instanceof self)
      {
        $child->showChildsTree($level+1);
      }
      else
      {
        echo "<br/>".str_repeat('&nbsp;', $level+1).$child->getName();
      }   
    }
  }
}
?>

<?php
$root = new CDirectory('root');
$dir1 = new CDirectory('dir1', $root);
$dir2 = new CDirectory('dir2', $root);
$dir3 = new CDirectory('dir3', $root);
$dir4 = new CDirectory('dir4', $dir2);
$file1 = new CFile('file1','txt', $dir1);
$file2 = new CFile('doc', 'pdf', $dir4);
 
$root->showChildsTree();
?>