PHP Currency Conversion Script

CurrencyConverter.php

<?php

/*
* File: CurrencyConverter.php
* Author: Simon Jarvis
* Copyright: 2005 Simon Jarvis
* Date: 10/12/05
* Link: http://www.white-hat-web-design.co.uk/articles/php-currency-conversion.php
* 
* This program is free software; you can redistribute it and/or 
* modify it under the terms of the GNU General Public License 
* as published by the Free Software Foundation; either version 2 
* of the License, or (at your option) any later version.
* 
* This program is distributed in the hope that it will be useful, 
* but WITHOUT ANY WARRANTY; without even the implied warranty of 
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
* GNU General Public License for more details: 
* http://www.gnu.org/licenses/gpl.html
*
*/

class CurrencyConverter {
	
	private $xml_file = "www.ecb.int/stats/eurofxref/eurofxref-daily.xml";
	private $mysql_host, $mysql_user, $mysql_pass, $mysql_db, $mysql_table;
	private $exchange_rates = array();

	//Load Currency Rates
	public function __construct($host,$user,$pass,$db,$tb) {
		$this->mysql_host = $host;
		$this->mysql_user = $user;
		$this->mysql_pass = $pass;
		$this->mysql_db = $db;
		$this->mysql_table = $tb;

		$this->checkLastUpdated();

		$conn = mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);
		$rs = mysql_select_db($this->mysql_db,$conn);

		$sql = "SELECT * FROM ".$this->mysql_table;
		$rs =  mysql_query($sql,$conn);
	
		while($row = mysql_fetch_array($rs)) {
			$this->exchange_rates[$row['currency']] = $row['rate'];			
		}
	}

	/* Perform the actual conversion, defaults to £1.00 GBP to USD */
	public function convert($amount=1,$from="GBP",$to="USD",$decimals=2) {
		return number_format(($amount/$this->exchange_rates[$from])*$this->exchange_rates[$to],$decimals);
	}

	/* Check to see how long since the data was last updated */
	private function checkLastUpdated() {
		$conn = mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);

		$rs = mysql_select_db($this->mysql_db,$conn);

		$sql = "SHOW TABLE STATUS FROM ".$this->mysql_db." LIKE '".$this->mysql_table."'";

		$rs =  mysql_query($sql,$conn);

		if(mysql_num_rows($rs) == 0 ) {
			$this->createTable();
		} else {
			$row = mysql_fetch_array($rs);
			if(time() > (strtotime($row["Update_time"])+(12*60*60)) ) {
				$this->downloadExchangeRates();			
			}
		}
	}

	/* Download xml file, extract exchange rates and store values in database */
	private function downloadExchangeRates() {
		$currency_domain = substr($this->xml_file,0,strpos($this->xml_file,"/"));
		$currency_file = substr($this->xml_file,strpos($this->xml_file,"/"));
		$fp = @fsockopen($currency_domain, 80, $errno, $errstr, 10);
		if($fp) {
			$out = "GET ".$currency_file." HTTP/1.1\r\n";
			$out .= "Host: ".$currency_domain."\r\n";
			$out .= "User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8) Gecko/20051111 Firefox/1.5\r\n";
			$out .= "Connection: Close\r\n\r\n";
			fwrite($fp, $out);
			while (!feof($fp)) {
				$buffer .= fgets($fp, 128);
			}
			fclose($fp);

			$pattern = "{<Cube\s*currency='(\w*)'\s*rate='([\d\.]*)'/>}is";
			preg_match_all($pattern,$buffer,$xml_rates);
			array_shift($xml_rates);

			for($i=0;$i<count($xml_rates[0]);$i++) {
				$exchange_rate[$xml_rates[0][$i]] = $xml_rates[1][$i];
			}

			$conn = mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);

			$rs = mysql_select_db($this->mysql_db,$conn);
				
			foreach($exchange_rate as $currency=>$rate) {
				if((is_numeric($rate)) && ($rate != 0)) {
					$sql = "SELECT * FROM ".$this->mysql_table." WHERE currency='".$currency."'";
					$rs =  mysql_query($sql,$conn) or die(mysql_error());
					if(mysql_num_rows($rs) > 0) {
						$sql = "UPDATE ".$this->mysql_table." SET rate=".$rate." WHERE currency='".$currency."'";
					} else {
						$sql = "INSERT INTO ".$this->mysql_table." VALUES('".$currency."',".$rate.")";
					}
					$rs =  mysql_query($sql,$conn) or die(mysql_error());
				}
			}	
		}
	}

	/* Create the currency exchange table */
	private function createTable() {
		$conn = mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);
		$rs = mysql_select_db($this->mysql_db,$conn);

		$sql = "CREATE TABLE ".$this->mysql_table." ( currency char(3) NOT NULL default '', rate float NOT NULL default '0', PRIMARY KEY(currency) ) ENGINE=MyISAM";
		$rs =  mysql_query($sql,$conn) or die(mysql_error());

		$sql = "INSERT INTO ".$this->mysql_table." VALUES('EUR',1)";
		$rs =  mysql_query($sql,$conn) or die(mysql_error());
		
		$this->downloadExchangeRates();	
	}

}

?>

Thank you so much for this! I've used it for a while and it works like clockwork! :)