GoogleTranslator.class.php

<?php

/**
 * GoogleTranslator for PHP - library for translating text via Google Translator API.
 *
 * @author     David Grudl
 * @author     Will Skates
 * @copyright  Copyright (c) 2010 David Grudl
 * @license    New BSD License
 * @link       http://phpfashion.com/
 * @link       http://twitter.com/willskates
 * @version    1.0 - Modified (Will Skates).
 */
abstract class GoogleTranslator
{
	
	// An array to store the language params.
	public static $langs = array(
		'sourceLang'=>'',
		'destLang'=>''
	);
	
	//An array to contain a list of translations which are already complete.
	public static $translations = array();
	
	// ------------------------------------------------------------------------
	
	/**
	 * Translate.
	 * 
	 * Translates text from a source to a destination language.
	 * 
	 * Note: Source and destination language references must be in ISO format (e.g. en,de)
	 * 
	 * @param	String 	$text 		- The text we want to translate.
	 * @param	String 	$sourceLang - The source language reference (optional).
	 * @param	String	$destLang	- The destination language reference (optional).
	 */
	public static function translate($text,$sourceLang = false,$destLang = false)
	{
	
		//Store the variable names that we need to access (these are mimiced in self::$langs).
		$vars = array('sourceLang','destLang');		
		foreach ($vars as $k=>$v) { 
			/*
			 * Check to see if the parameter was passed with the function.
			 * If not, use one that has already been set (if possible).
			 */
			if ( $$v === false ) { $$v = self::$langs[$v]; }
			if ( empty($$v) ) { 
				throw new GoogleTranslatorException('No value was set for ' . $v . '.');
			}
		}
		
		//Create an array reference string for this translation.
		$ref = md5($text . $sourceLang . $destLang);
		
		//If we've already done the work, don't bother doing it again.
		if ( isset(self::$translations[$ref]) ) { return self::$translations[$ref]; }
		
		
		//Get the translation from the api.
		$curl = curl_init();
		curl_setopt($curl, CURLOPT_URL, 'http://ajax.googleapis.com/ajax/services/language/translate');
		curl_setopt($curl, CURLOPT_HEADER, FALSE);
		curl_setopt($curl, CURLOPT_TIMEOUT, 20);
		curl_setopt($curl, CURLOPT_RETURNTRANSFER, TRUE); // no echo, just return result
		curl_setopt($curl, CURLOPT_POSTFIELDS, array(
			'v' => '1.0',
			'langpair' => $sourceLang . '|' . $destLang,
			'q' => (string) $text
		));

		$result = curl_exec($curl);
		if (curl_errno($curl)) {
			throw new GoogleTranslatorException('Server error: ' . curl_error($curl));
		}

		$code = curl_getinfo($curl, CURLINFO_HTTP_CODE);
		if ($code != 200) {
			throw new GoogleTranslatorException("Server error #$code", $code);
		}

		$json = @json_decode($result); // intentionally @ - Why?
		if (!isset($json->responseData->translatedText)) {
			throw new GoogleTranslatorException('Invalid server response');
		}
		
		//Make sure we don't have to make the translation a second time.
		self::$translations[$ref] = $json->responseData->translatedText;
		
		return self::$translations[$ref];
		
	}
	
	// ------------------------------------------------------------------------
	
	/**
	 * Set Languages
	 * 
	 * In case the developer using this class wants to batch process a lot of
	 * translations from one to another, allow them to set the translation languages here.
	 * 
	 * The function also allows either parameter to be optional so that they can be set 
	 * individually.
	 * 
	 * E.g.
	 * To set the source: 		GoogleTranslator::setLanguages('en');
	 * To set the destination:	GoogleTranslator::setLanguages(false,'de');
	 * To set both:				GoogleTranslator::setLanguages('en','de');
	 * 
	 * @param	String 	$sourceLang - The source language reference (optional).
	 * @param	String	$destLang	- The destination language reference (optional).
	 */
	public static function setLanguages($sourceLang = false,$destLang = false)
	{
		
		if ($sourceLang === false && $destLang === false ) {
			throw new GoogleTranslatorException('You must set either a source or destination language.');
		}
		
		$vars = array('sourceLang','destLang');
		foreach ($vars as $k=>$v) { if ( $$v !== false ) { self::$langs[$v] = $$v; } }
	}
	
	// ------------------------------------------------------------------------


}



/**
 * An exception generated by GoogleTranslator.
 */
class GoogleTranslatorException extends Exception
{
}