<?php
/**
 OOB/N1 Framework [©2004, 2005 - Nutus]
 @license: BSD
 @author: Pablo Micolini / Nutus 2005
 OOB/N1 Framework:: Advanced Resources Integration (ARI)
 
 Provides safe-forms by checking that a form can't be sent twise avoiding duplicate data
*/
class OOB_safepost {


	private $llave = array ();
	private $hayllave = FALSE;
	private $form_name;


/** The form name must be provided to the constructor */	
	public function __construct ($form = 'form')
	{
	$this->form_name = $form;
	}

/** Start the safe form */	
	public function Iniciar() {
		if ($this->hayllave == FALSE) {
			$this->llave[0] = md5(microtime());
			$this->llave[1] = md5(rand());
			$_SESSION[$this->form_name .'_'.$this->llave[1]] = $this->llave[0];
			} 
		$this->hayllave = TRUE;
		return $this->llave;
	} 

	
/** Provides the form code that must be passed to the output */
	public function FormElement() {
		if ($this->hayllave === FALSE)
		$this->Iniciar();
		
		return  '<input name="' . $this->form_name . '-0" type="hidden" value="' . $this->llave[0] . '" />' .
				'<input name="' . $this->form_name . '-1" type="hidden" value="' . $this->llave[1] . '" />';
	} 

/** Validates the form, and returns false if it has been already posted */
	public function Validar() {

			if (isset($_POST[$this->form_name . "-0"]) && isset($_POST[$this->form_name . "-1"]) && isset($_SESSION[$this->form_name . '_' .$_POST[$this->form_name . "-1"]]) && $_SESSION[$this->form_name . '_' .$_POST[$this->form_name . "-1"]] === $_POST[$this->form_name . "-0"])
			{
			unset ($_SESSION[$this->form_name . '_' .$_POST[$this->form_name . "-1"]]);
			return TRUE; 	
			}
			else
			return FALSE;
			
	} 
	

	

} 
?>