PHP Classes

File: Node.php

Recommend this page to a friend!
  Classes of m   Node   Node.php   Download  
File: Node.php
Role: Class source
Content type: text/plain
Description: The node class file
Class: Node
Build an hierarchic tree of node elements
Author: By
Last change: added new basic method.
revised the addChild method.
revised export and import method.
Date: 17 years ago
Size: 7,081 bytes
 

Contents

Class file image Download
<?php
/**
 * Node class file
 * @author Mathieu Lachance <lachance.mathieu@poincomm.com>
 * @link http://www.mathieulachance.com/
 * @copyright Copyright (c) 2007 Mathieu Lachance
 * @license http://creativecommons.org/licenses/by/2.5/ca/
 * @version 2.0 2007-03-15 15h45
 */

/**
 * Class Node
 * The Node class is used to generate a tree architecture.
 * Each Node contains :
 * - a name, wich is not necessarly unique to the tree, the $name protected property
 * - the reference of his parent, the $parent protected property
 * - an integer indexed array containing all the references of the child nodes, the $child protected property
 *
 * When adding a new Node with the addChild method, the node class generate a public user defined property called
 * as same as the new Node name.
 * Therefore, this kind of dynamic property can be accessed freely with the powerfull syntax :
 * - $tree->nodeName->... when there is only one node named nodeName
 * - $tree->nodeName[index]->... when there is more than one node named nodeName
 *
 * Moreover, each node can be exported as xml with the use of the export method.
 * They can be re-imported from xml with the combine use of SimpleXML extension and the import method.
 * - TO DO : find a better way than using SimpleXML extension
 */
class Node
{
 
/**
  * @var string $name the node name
  */
 
protected $name = null;
 
/**
  * @var Node $parent a reference to the parent node
  */
 
protected $parent = null;
 
/**
  * @var array $children an integer indexed array containing all the references to the child nodes
  */
 
protected $children = null;
 
/**
  * @var int $count the number of child nodes
  */
 
protected $count = null;
 
 
/**
   * Constructor
   * @param string $name the node name
   */
 
public function __construct($name = null){
   
$this->name = (string)$name; // ensure the $name is a string an assign it to the node name
   
$this->children = array(); // initialise the childs array
   
$this->count = 0; // initialise the count of the childs array
 
}
 
 
/**
   * Wether :
   * - create a public user defined property called by the node $n name and
   * assign the node $n to this user defined property
   * - append the node $n to the public user defined property called by the node $n name
   * @param Node $n the node to append
   */
 
public function addChild(Node $n){
   
$n->parent = $this; // assign the parent node to the node $n
   
$name = $n->name; // get the node name
   
if (!(isset($this->$name))) { // check wether the public user defined property $name is already defined
     
$this->$name = $n; // assign the node $n to the user defined property $name
   
}
    else{
      if (!(
is_array($this->$name))){ // if the public user defined property $name is not an array containing nodes
       
$this->$name = array($this->$name); // convert the user defined property as an array
     
}
     
array_push($this->$name, $n); // append the new node $n to the user defined property
   
}
   
array_push($this->children, $n); // append the new node $n to the childs array
   
$this->count++; // increments $this->count the number of child nodes
   
   
return $n;
  }
 
 
/**
   * @return string $name the node name
   */
 
public function getName(){
    return
$this->name;
  }
 
 
/**
   * @return Node $parent the reference to the parent node
   */
 
public function getParent(){
    return
$this->parent;
  }
 
 
/**
   * @return array $children the integer indexed array containing all the references to the child nodes
   */
 
public function getChildren(){
    return
$this->children;
  }
 
 
/**
   * @return int $count the number of child nodes
   */
 
public function getChildrenCount(){
    return
$this->count;
  }

 
/**
   * @return bool wether : true if there is no child contained in the children array, else false
   */
 
public function isEmpty(){
    return (
$this->count == 0);
  }
 
 
/**
   * export the node and all his childs to an xml format
   * @param $level the node indentation deep
   * @return string $x the xml output of the node
   */
 
public function export($level = null){
   
$level = (int)$level;
                                           
// if it's the root level element
   
$ws = str_repeat(" ", $level); // calculate the whitespace, TO DO : this one could be a constant
   
if ($this->count == 0){ // if the current node is empty
     
return "$ws<$this->name/>\n"; // return a closing tag of the current node name as the xml output
   
}
   
$x = "$ws<$this->name>\n"; // open an tag of the current node name
   
foreach($this->children as $child){ // for each child of the current node
     
$x .= $child->export($level+1); // export the child node
   
}
   
$x .= "$ws</$this->name>\n"; // close the opened tag of the current node name
   
return $x; // return the xml output of the current node
 
}

 
/**
   * @return the xml output of the node
   */
 
public function __toString(){
    return
$this->export();
  }
 
 
/**
   * import all xml nodes from a SimpleXMLElement
   * @param SimpleXMLElement $sxe the xml fragment of the last import method iteration
   * @param Node $p the parent node reference of the last import method iteration
   */
 
public function import(SimpleXMLElement $sxe, Node $p = null){
   
$this->name = $sxe->getName(); // reasign the node name with the root element of the SimpleXMLElelment
   
$this->parent = $p; // assign the parent node
   
if (count($sxe->children()) > 0){ // if the xml node is not empty
     
foreach($sxe->children() as $child){ // for each children
       
$n = new Node($child->getName()); // create the new node
       
$this->addChild($n); // append the new node
       
$n->import($child, $this); // now import all nodes from the child element of the SimpleXMLElement
     
}
    }
  }

}


/* start of benchmark */
$start = microtime(true);

/* export test */
$n = new Node("html");
$n->addChild(new Node("head"));
$n->head->addChild(new Node("meta"));
$n->head->addChild(new Node("meta"));
$n->addChild(new Node("body"));
$n->body->addChild(new Node("div"));
$n->body->addChild(new Node("div"));
$n->body->div[1]->addChild(new Node("span"));

echo
$n->export(); // ouput : <html><head><meta /><meta /></head><body><div /><div><span /></div></body></html>

/* import test */
$x = new SimpleXMLElement($n->export());
$n = new Node();
$n->import($x);

echo
$n->export(); // ouput : <html><head><meta /><meta /></head><body><div /><div><span /></div></body></html>

/* serialization test */
$n = serialize($n);
$n = unserialize($n);

echo
$n->export(); // ouput : <html><head><meta /><meta /></head><body><div /><div><span /></div></body></html>

/* end of benchmark */
$end = microtime(true);
echo
$end - $start; // ouput : 0.00128698348999

?>