if ( $data !== false )
			return json_decode($data);
		return false;
	}
	
	/**
	* Get unsecured Url (no login / no IP check) to a private publication
	*
	* @param integer $pub_id Publication's ID
	* @param integer $page_nr (optional) Direct Url to a page
	* @param integer $expdelay (optional) Lifetime of the generated Url
	* @return void
	*/
	public function getUnsecuredUrl( $pub_id, $page_nr = 1, $expdelay = 0 ) {
		$pub_id = intval($pub_id);
		$page_nr = intval($page_nr);
		$page_nr = $page_nr < 1 ? 1 : $page_nr;
		$expdelay = intval($expdelay);
		$expdelay = $expdelay > 0 ? $expdelay : $this->expdelay;
		$time = self::timestamp();
		$hash = self::hash( self::$accesskey, self::$secretkey, $time, $expdelay, $pub_id, ( $page_nr > 1 ? $page_nr : 1 ) );				
		return $url = self::$ppurl.'?cmd=uu&h='.$hash.'&aki='.self::$accesskey.'&time='.$time.'&exp='.$expdelay.'&pub='.$pub_id.( $page_nr > 1 ? '&page='.$page_nr : '' );		
  	}
  
	/**
	* Set request expire delay in seconds
	*
	* @param integer $expdelay Keep the query alive to $expdelay seconds
	* @return void
	*/
	public function setExpDelay( $expdelay ) {
		$this->expdelay = intval($expdelay);
 	}
  
  	/**
	* Get server's timestamp in GMT +0000 timezon
	*
	* @return integer
	*/
	private static function timestamp() {
		$dtzone = new DateTimeZone('Europe/London');
		$dtime = new DateTime( 'now', $dtzone );		
		return $dtime->getTimestamp();
	}
		
	/**
	* Generate hash code from arguments
	*
	* @return string
	*/
	public static function hash() {
		$args = func_get_args();
		return substr(self::sha3(implode('',$args)),0,16);
  	}
  
  	/**
	* Encode string with sha512
	*
	* @param string $str
	* @return string
	*/
	private static function sha3($str) {
		return hash("sha512", $str);
	}


	/**
     * Get URL content
     * 
     * @param string $url URL to get
     * @param number $timeout timeout to wait for response.
     * @return mixed Return value or false.
     */
    public static function url( $url, $timeout = 5 ) {
    	$result = false;

    	//check if curl_init available
        if ( is_callable('curl_init') ) {
            try {
				$ch = curl_init();

				curl_setopt($ch, CURLOPT_URL, $url);
    			curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    			curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
    			curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);                    
                   
                $result = @curl_exec($ch);
                   
                curl_close($ch);
            } catch (Exception $e) {
            }
        } else {
        	$context = stream_context_create( 
		        			array( 
		        				'http'=> array( 
		        					'timeout' => $timeout,
		        				), 
		        				'https'=> array(
		        					'timeout' => $timeout,
		        				),        			
			        			'ssl' => array(
							        'verify_peer' => false,
							    )
			        		)
		        		);        	
            $result = @file_get_contents( $url, false, $context );
        }

        return $result;
    }
	
}

?>