CI Library - Array Structure

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**
 * Scribble
 *
 * @author		Pascal Kriete
 * @package		Scribble
 * @copyright	Copyright (c) 2008, Pascal Kriete
 */

// ------------------------------------------------------------------------

/**
 * Structure Helper Library
 *
 * @package		Scribble
 * @subpackage	Libraries
 * @category	Structure
 * @author		Pascal Kriete
 */
class Structure {

	var $_struct = array();

	/**
	 * Constructor
	 *
	 * @access	public
	 */
	function Structure($data)
	{
		$this->_struct = $data[0];
		
		/* Json:
		Structure = {
			"4893j4f": {"title":"firsttitle"},
			"485hfkd": {"title":"secondtitle"},
			"kg84083": {"title":"thirdtitle","children": {
				"fkjowi":{"title":"firstchild"},
				"8j4tjd":{"title":"secondchild"}
			}},
			"9088jl": {"title":"fourthtitle"}}
		
		$structure = array(
					'4893j4f' => array('title' => 'firsttitle'),
					'485hfkd' => array('title' => 'secondtitle'),
					'kg84083' => array('title' => 'thirdtitle', 'children' => array(
								'fkjowi' => array('title' => 'firstchild'),
								'8j4tjd' => array('title' => 'secondchild')
						)
					),
					'9088jl' => array('title' => 'fourthtitle')
				);
		
		$this->_struct = $structure;
		
		$this->move_node('8j4tjd', '8j4tjd');
//		$this->remove_node('kg84083');
//		$this->add_node('abcdef', array('title' => 'NEW NODE!'), '9088jl');
		
		echo '<pre>';
		print_r($this->_struct);
		echo '</pre>';

		exit;
		*/
	}
	
	// --------------------------------------------------------------------

	/**
	 * Accessor
	 *
	 * @access	public
	 */
	function get()
	{
		return $this->_struct;
	}
	
	// --------------------------------------------------------------------

	/**
	 * Add a node to the current structure
	 *
	 * @access	public
	 * @param	string	new node identifier
	 * @param	mixed	array of new node data
	 * @param	string	parent identifier
	 */
	function add_node($node_id, $node_data, $parent_id = FALSE)
	{
		// Parent given?
		if ( ! $parent_id)
		{
			$this->_struct[$node_id] = $node_data;
		}
		else
		{
			// Get a path to the new parent
			$path = $this->get_path($parent_id);
			
			if ( ! $path)
			{
				return FALSE;
			}
			
			// And now a reference
			$ref =& $this->get_reference($path);
			
			$ref['children'][$node_id] = $node_data;
		}
		return TRUE;
	}
	
	// --------------------------------------------------------------------

	/**
	 * Remove a node from the current structure
	 *
	 * @access	public
	 * @param	string	node identifier
	 * @param	bool	delete child tree?
	 */
	function remove_node($node_id, $inherit_children = FALSE)
	{
		// Does the node even exist?
		$path = $this->get_path($node_id);
		
		if ( ! $path)
		{
			return FALSE;
		}

		// Get a reference to the parent
		$parent =& $this->_struct;
		
		// Not on the root node
		if (count($path) > 1)
		{
			$tmp = array_slice($path, 0, -1, TRUE);
			$parent =& $this->get_reference($tmp);
		}
		
		// Get a reference to the node
		$ref =& $this->get_reference($path);
		
		// If inherit_children is true - save them first
		if ($inherit_children && isset($ref['children']))
		{
			foreach($ref['children'] as $key => &$value)
			{
				$parent[$key] = $value;
			}
		}

		// And finally kill it
		unset($parent[$node_id]);
		return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	 * Move a node to a new position
	 *
	 * @access	public
	 * @param	string	node identifier
	 * @param	string	new parent identifier (0 for root)
	 */
	function move_node($node_id, $new_parent_id)
	{
		// Nonsense
		if ($node_id === $new_parent_id)
		{
			return TRUE;
		}
		
		// Does the node even exist?
		$path = $this->get_path($node_id);
		$p_path = $this->get_path($new_parent_id);
		
		if ($new_parent_id == '0')
		{
			$p_path = array();
		}

		if ( ! $path OR ( ! $p_path AND $new_parent_id != '0'))
		{
			return FALSE;
		}
		
		// Get a reference to the parent(s)
		$parent =& $this->_struct;
		$new_parent =& $this->get_reference($p_path);
		
		// Not attached to the root node
		if (count($path) > 1)
		{
			$tmp = array_slice($path, 0, -1, TRUE);
			$parent =& $this->get_reference($tmp);
		}
		
		if ($new_parent_id != '0')
		{
			// New parent needs a 'children' key
			if ( ! isset($new_parent['children']))
			{
				$new_parent['children'] = array();
			}

			$new_parent =& $new_parent['children'];
		}

		// Get a reference to the node
		$ref =& $this->get_reference($path);
		
		// Move it to the new parent
		$new_parent[$node_id] = $ref;

		// And finally kill it
		unset($parent[$node_id]);
		return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	 * Get reference to the element at the end of the given path
	 *
	 * @access	public
	 * @param	array	path array
	 * @return	ref		reference to the array segment
	 */
	function &get_reference($path)
	{
		$subject =& $this->_struct;
		
		foreach($path as $node)
		{
			$subject =& $subject[$node];
		}
		
		return $subject;
	}

	// --------------------------------------------------------------------

	/**
	 * Get path to the id
	 *
	 * @access	public
	 * @param	array	array to search
	 * @param	int		id of the node to find
	 * @return	array	array of nodes in the path
	 */
	function get_path($id)
	{
		return $this->_get_path_callback($id, $this->_struct);
	}

	// --------------------------------------------------------------------
	
	/**
	 * Recursive function that does the work for get_path
	 *
	 * @access	private
	 * @param	int		id of the node to find
	 * @param	array	array to search
	 * @param	array	recursive path array
	 * @return	array	array of nodes in the path
	 */
	function _get_path_callback($needle, $haystack, $path = array())
	{
		foreach($haystack as $key => $val)
		{
			if($key == $needle)
			{
				$path[] = $key;
				return $path;
			}
			else if ( is_array($val) && $sub_path = $this->_get_path_callback($needle, $val, $path))
			{
				$path = array_merge($path, Array($key), $sub_path);
				return $path;
			}
		}
		return FALSE;
	}
}

// END Structure class

/* End of file structure.php */
/* Location: ./application/libraries/structure.php */