Subversion-Projekte lars-tiefland.prado

<?php

/**
 * MessageFormat class file.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the BSD License.
 *
 * Copyright(c) 2004 by Qiang Xue. All rights reserved.
 *
 * To contact the author write to {@link mailto:qiang.xue@gmail.com Qiang Xue}
 * The latest version of PRADO can be obtained from:
 * {@link http://prado.sourceforge.net/}
 *
 * @author Wei Zhuo <weizhuo[at]gmail[dot]com>
 * @version $Revision: 1.5 $  $Date: 2005/08/27 03:21:12 $
 * @package System.I18N.core
 */

/**
 * Get the MessageSource classes.
 */
require_once(dirname(__FILE__).'/MessageSource.php');

/**
 * Get the encoding utilities
 */
require_once(dirname(__FILE__).'/util.php');

/**
 * MessageFormat class.
 * 
 * Format a message, that is, for a particular message find the 
 * translated message. The following is an example using 
 * a SQLite database to store the translation message. 
 * Create a new message format instance and echo "Hello"
 * in simplified Chinese. This assumes that the world "Hello"
 * is translated in the database.
 *
 * <code>
 *  $source = MessageSource::factory('SQLite', 'sqlite://messages.db');
 *      $source->setCulture('zh_CN');
 *      $source->setCache(new MessageCache('./tmp'));
 *
 *      $formatter = new MessageFormat($source); 
 *      
 *      echo $formatter->format('Hello');
 * </code>
 *
 * @author Xiang Wei Zhuo <weizhuo[at]gmail[dot]com>
 * @version v1.0, last update on Fri Dec 24 20:46:16 EST 2004
 * @package System.I18N.core
 */
class MessageFormat
{
        /**
         * The message source.
         * @var MessageSource 
         */
        protected $source;
        
        /**
         * A list of loaded message catalogues.
         * @var array 
         */
        protected $catagloues = array();
        
        /**
         * The translation messages.
         * @var array 
         */
        protected $messages = array();
        
        /**
         * A list of untranslated messages.
         * @var array 
         */
        protected $untranslated = array();
        
        /**
         * The prefix and suffix to append to untranslated messages.
         * @var array 
         */
        protected $postscript = array('','');
        
        /**
         * Set the default catalogue.
         * @var string 
         */
        public $Catalogue;

        /**
         * Output encoding charset
         * @var string
         */
        protected $charset = 'UTF-8'; 

        /**
         * Constructor.
         * Create a new instance of MessageFormat using the messages
         * from the supplied message source.
         * @param MessageSource the source of translation messages.
         * @param string charset for the message output.
         */
        function __construct(IMessageSource $source, $charset='UTF-8')
        {
                $this->source = $source;        
                $this->setCharset($charset);
        }

        /** 
         * Sets the charset for message output.
         * @param string charset, default is UTF-8
         */
        public function setCharset($charset)
        {
                $this->charset = $charset;
        }

        /**
         * Gets the charset for message output. Default is UTF-8.
         * @return string charset, default UTF-8
         */
        public function getCharset()
        {
                return $this->charset;
        }
        
        /**
         * Load the message from a particular catalogue. A listed
         * loaded catalogues is kept to prevent reload of the same
         * catalogue. The load catalogue messages are stored
         * in the $this->message array.
         * @param string message catalogue to load.
         */
        protected function loadCatalogue($catalogue)
        {
                if(in_array($catalogue,$this->catagloues))
                        return;
                        
                if($this->source->load($catalogue))
                {
                        $this->messages[$catalogue] = $this->source->read();
                        $this->catagloues[] = $catalogue;                                               
                }
        }

        /**
         * Format the string. That is, for a particular string find
         * the corresponding translation. Variable subsitution is performed
         * for the $args parameter. A different catalogue can be specified
         * using the $catalogue parameter.
         * The output charset is determined by $this->getCharset();
         * @param string the string to translate.
         * @param array a list of string to substitute.
         * @param string get the translation from a particular message
         * @param string charset, the input AND output charset
         * catalogue.
         * @return string translated string.
         */
        public function format($string,$args=array(), $catalogue=null, $charset=null) 
        {
                if(empty($charset)) $charset = $this->getCharset();
                
                //force args as UTF-8
                foreach($args as $k => $v)
                        $args[$k] = I18N_toUTF8($v, $charset);
                $s = $this->formatString(I18N_toUTF8($string, $charset),$args,$catalogue);
                return I18N_toEncoding($s, $charset);
        }

        /**
         * Do string translation.
         * @param string the string to translate.
         * @param array a list of string to substitute.
         * @param string get the translation from a particular message
         * catalogue.
         * @return string translated string.
         */
        protected function formatString($string, $args=array(), $catalogue=null)
        {               
                if(empty($catalogue))
                {
                        if(empty($this->Catalogue))
                                $catalogue = 'messages';
                        else 
                                $catalogue = $this->Catalogue;
                }
                                
                $this->loadCatalogue($catalogue);
                
                if(empty($args))
                        $args = array();                
                
                foreach($this->messages[$catalogue] as $variant)
                {
                        // foreach of the translation units
                        foreach($variant as $source => $result)
                        { 
                                // we found it, so return the target translation
                                if($source == $string)
                                {
                                        //check if it contains only strings.
                                        if(is_string($result))
                                                $target = $result;
                                        else
                                        {
                                                $target = $result[0];
                                        }
                                        //found, but untranslated
                                        if(empty($target))
                                        {
                                                return  $this->postscript[0].
                                                                strtr($string, $args).
                                                                $this->postscript[1];           
                                        }
                                        else
                                                return strtr($target, $args);
                                }
                        }
                }
                
                // well we did not find the translation string.
                $this->source->append($string);
                
                return  $this->postscript[0].
                                strtr($string, $args).
                                $this->postscript[1];
        }
        
        /**
         * Get the message source.
         * @return MessageSource 
         */
        function getSource()
        {
                return $this->source;
        }
        
        /**
         * Set the prefix and suffix to append to untranslated messages.
         * e.g. $postscript=array('[T]','[/T]'); will output 
         * "[T]Hello[/T]" if the translation for "Hello" can not be determined.
         * @param array first element is the prefix, second element the suffix.
         */
        function setUntranslatedPS($postscript)
        {
                if(is_array($postscript) && count($postscript)>=2)
                {
                        $this->postscript[0] = $postscript[0];
                        $this->postscript[1] = $postscript[1];
                }
        }
}