/system/core/Lang.php 语言类

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * Language Class
 * 语言类
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Language
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/libraries/language.html
 */
class CI_Lang {

	/**
	 * List of translations
	 * 翻译列表
	 * @var array
	 */
	var $language	= array();
	
	
	/**
	 * List of loaded language files
	 * 加载的语言文件列表
	 * @var array
	 */
	var $is_loaded	= array();

	
	/**
	 * Constructor
	 *
	 * @access	public
	 */
	function __construct()
	{
		log_message('debug', "Language Class Initialized 语言类初始化");
	}

	// --------------------------------------------------------------------

	/**
	 * Load a language file
	 * 加载语言文件
	 * @access	public
	 * @param	mixed	the name of the language file to be loaded. Can be an array
	 * 语言文件的名称被载入。可以是一个数组
	 * @param	string	the language (english, etc.)
	 * @param	bool	return loaded array of translations 返回翻译加载阵列
	 * @param 	bool	add suffix to $langfile 增加至$ langfile的后缀
	 * @param 	string	alternative path to look for language file 替代路径寻找语言文件
	 * @return	mixed
	 */
	function load($langfile = '', $idiom = '', $return = FALSE, $add_suffix = TRUE, $alt_path = '')
	{
		//将语言文件中的.php后缀去掉
		$langfile = str_replace('.php', '', $langfile);

		//如果添加后后缀为真时
		if ($add_suffix == TRUE)
		{
			//将$langfile里抽_lang.去掉，然后在后面在加上这个字会
			$langfile = str_replace('_lang.', '', $langfile).'_lang';
		}
        //然后添加.php后缀，这添加来添加去的，干嘛呢>>>
		$langfile .= '.php';

		//如果该文件在已经加载的语言包数据中已经存在，就直接返回
		if (in_array($langfile, $this->is_loaded, TRUE))
		{
			return;
		}

		$config =& get_config(); //配置文件对象

		//
		if ($idiom == '')
		{
			//如果没有设置默认的语言，那么设置为english
			$deft_lang = ( ! isset($config['language'])) ? 'english' : $config['language'];
			$idiom = ($deft_lang == '') ? 'english' : $deft_lang;
		}

		// Determine where the language file is and load it
		// 确定语言文件并加载它
		if ($alt_path != '' && file_exists($alt_path.'language/'.$idiom.'/'.$langfile))
		{
			include($alt_path.'language/'.$idiom.'/'.$langfile); //如果存在，直接引用语言包
		}
		else
		{
			$found = FALSE;

			//get_instance() 是$CI对象
			//$this->_ci_library_paths
			//get_package_paths(true) 返回所有_ci_library_paths中的路径信息
			//然后循环在这些目录里面查找语言文件
			foreach (get_instance()->load->get_package_paths(TRUE) as $package_path)
			{
				if (file_exists($package_path.'language/'.$idiom.'/'.$langfile))
				{
					include($package_path.'language/'.$idiom.'/'.$langfile);
					$found = TRUE;
					break;
				}
			}

			if ($found !== TRUE)
			{
				show_error('Unable to load the requested language file 无法加载请求的语言文件: language/'.$idiom.'/'.$langfile);
			}
		}


		//如果语言文件中没有$lang的话
		if ( ! isset($lang))
		{
			log_message('error', 'Language file contains no data 语言文件不包含任何数据: language/'.$idiom.'/'.$langfile);
			return;
		}

		//如果$return==true直接将语言文件内容返回
		if ($return == TRUE)
		{
			return $lang;
		}

		//将该文件放入is_loaded数组中去
		$this->is_loaded[] = $langfile;
		//然后将language与$lang数组进行合并
		$this->language = array_merge($this->language, $lang);
		unset($lang);

		log_message('debug', 'Language file loaded 语言文件加载: language/'.$idiom.'/'.$langfile);
		return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	 * Fetch a single line of text from the language array
	 * 从语言数组取一行文字
	 * @access	public
	 * @param	string	$line	the language line 语言线
	 * @return	string
	 */
	function line($line = '')
	{
		$value = ($line == '' OR ! isset($this->language[$line])) ? FALSE : $this->language[$line];

		// Because killer robots like unicorns!
		// 因为杀手机器人像独角兽！
		if ($value === FALSE)
		{
			log_message('error', 'Could not find the language line  找不到语言在线 "'.$line.'"');
		}

		return $value;
	}

}
// END Language Class

/* End of file Lang.php */
/* Location: ./system/core/Lang.php */