CI框架装载器Loader.php源码分析

顾名思义，装载器就是加载元素的，使用CI时，经常加载的有：

$this->load->library()
$this->load->view()
$this->load->model()
$this->load->database()
$this->load->helper()
$this->load->config()
$this->load->add_package_path()

/**

 * Loader Class

 *

 * 用户加载views和files，常见的函数有model(),view(),library(),helper()

 * 

 * Controller的好助手，$this->load =& load_class('Loader', 'core');，加载了loader，Controller就无比强大了

 */

class CI_Loader {

 protected $_ci_ob_level;

 protected $_ci_view_paths  = array();

 protected $_ci_library_paths = array();

 protected $_ci_model_paths  = array();

 protected $_ci_helper_paths  = array();

 protected $_base_classes  = array(); // Set by the controller class

 protected $_ci_cached_vars  = array();

 protected $_ci_classes   = array();

 protected $_ci_loaded_files  = array();

 

 protected $_ci_models   = array();

 protected $_ci_helpers   = array();

 protected $_ci_varmap   = array('unit_test' => 'unit',

           'user_agent' => 'agent');

 public function __construct()

 {       

                //获取缓冲嵌套级别

  $this->_ci_ob_level  = ob_get_level();

  //library路径

                $this->_ci_library_paths = array(APPPATH, BASEPATH);

                //helper路径

  $this->_ci_helper_paths = array(APPPATH, BASEPATH);

                //model路径

  $this->_ci_model_paths = array(APPPATH);

                //view路径

  $this->_ci_view_paths = array(APPPATH.'views/' => TRUE);

  log_message('debug', "Loader Class Initialized");

 }

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

 /**

  * 初始化Loader

  *

  */

 public function initialize()

 {

  $this->_ci_classes = array();

  $this->_ci_loaded_files = array();

  $this->_ci_models = array();

                //将is_loaded（common中记录加载核心类函数）加载的核心类交给_base_classes

  $this->_base_classes =& is_loaded();

                //加载autoload.php配置中文件

  $this->_ci_autoloader();

  return $this;

 }

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

 /**

  * 检测类是否加载

  */

 public function is_loaded($class)

 {

  if (isset($this->_ci_classes[$class]))

  {

   return $this->_ci_classes[$class];

  }

  return FALSE;

 }

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

 /**

  * 加载Class

  */

 public function library($library = '', $params = NULL, $object_name = NULL)

 {

  if (is_array($library))

  {

   foreach ($library as $class)

   {

    $this->library($class, $params);

   }

   return;

  }

                //如果$library为空或者已经加载。。。

  if ($library == '' OR isset($this->_base_classes[$library]))

  {

   return FALSE;

  }

  if ( ! is_null($params) && ! is_array($params))

  {

   $params = NULL;

  }

  $this->_ci_load_class($library, $params, $object_name);

 }

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

 /**

  * 加载和实例化model

  */

 public function model($model, $name = '', $db_conn = FALSE)

 {

                //CI支持数组加载多个model

  if (is_array($model))

  {

   foreach ($model as $babe)

   {

    $this->model($babe);

   }

   return;

  }

  if ($model == '')

  {

   return;

  }

  $path = '';

  // 是否存在子目录

  if (($last_slash = strrpos($model, '/')) !== FALSE)

  {

   // The path is in front of the last slash

   $path = substr($model, 0, $last_slash + 1);

   // And the model name behind it

   $model = substr($model, $last_slash + 1);

  }

  if ($name == '')

  {

   $name = $model;

  }

  if (in_array($name, $this->_ci_models, TRUE))

  {

   return;

  }

  $CI =& get_instance();

  if (isset($CI->$name))

  {

   show_error('The model name you are loading is the name of a resource that is already being used: '.$name);

  }

  $model = strtolower($model); //model文件名全小写

  foreach ($this->_ci_model_paths as $mod_path)

  {

   if ( ! file_exists($mod_path.'models/'.$path.$model.'.php'))

   {

    continue;

   }

   if ($db_conn !== FALSE AND ! class_exists('CI_DB'))

   {

    if ($db_conn === TRUE)

    {

     $db_conn = '';

    }

    $CI->load->database($db_conn, FALSE, TRUE);

   }

   if ( ! class_exists('CI_Model'))

   {

    load_class('Model', 'core');

   }

   require_once($mod_path.'models/'.$path.$model.'.php');

   $model = ucfirst($model);

   $CI->$name = new $model();

                        //保存在Loader::_ci_models中，以后可以用它来判断某个model是否已经加载过。

   $this->_ci_models[] = $name;

   return;

  }

  // couldn't find the model

  show_error('Unable to locate the model you have specified: '.$model);

 }

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

 /**

  * 数据库Loader

  */

 public function database($params = '', $return = FALSE, $active_record = NULL)

 {

  // Grab the super object

  $CI =& get_instance();

  // 是否需要加载db

  if (class_exists('CI_DB') AND $return == FALSE AND $active_record == NULL AND isset($CI->db) AND is_object($CI->db))

  {

   return FALSE;

  }

  require_once(BASEPATH.'database/DB.php');

  if ($return === TRUE)

  {

   return DB($params, $active_record);

  }

  // Initialize the db variable.  Needed to prevent

  // reference errors with some configurations

  $CI->db = '';

  // Load the DB class

  $CI->db =& DB($params, $active_record);

 }

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

 /**

  * 加载数据库工具类

  */

 public function dbutil()

 {

  if ( ! class_exists('CI_DB'))

  {

   $this->database();

  }

  $CI =& get_instance();

  // for backwards compatibility, load dbforge so we can extend dbutils off it

  // this use is deprecated and strongly discouraged

  $CI->load->dbforge();

  require_once(BASEPATH.'database/DB_utility.php');

  require_once(BASEPATH.'database/drivers/'.$CI->db->dbdriver.'/'.$CI->db->dbdriver.'_utility.php');

  $class = 'CI_DB_'.$CI->db->dbdriver.'_utility';

  $CI->dbutil = new $class();

 }

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

 /**

  * Load the Database Forge Class

  *

  * @return string

  */

 public function dbforge()

 {

  if ( ! class_exists('CI_DB'))

  {

   $this->database();

  }

  $CI =& get_instance();

  require_once(BASEPATH.'database/DB_forge.php');

  require_once(BASEPATH.'database/drivers/'.$CI->db->dbdriver.'/'.$CI->db->dbdriver.'_forge.php');

  $class = 'CI_DB_'.$CI->db->dbdriver.'_forge';

  $CI->dbforge = new $class();

 }

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

 /**

  * 加载视图文件

  */

 public function view($view, $vars = array(), $return = FALSE)

 {

  return $this->_ci_load(array('_ci_view' => $view, '_ci_vars' => $this->_ci_object_to_array($vars), '_ci_return' => $return));

 }

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

 /**

  * 加载普通文件

  */

 public function file($path, $return = FALSE)

 {

  return $this->_ci_load(array('_ci_path' => $path, '_ci_return' => $return));

 }

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

 /**

  * 设置变量

  *

  * Once variables are set they become available within

  * the controller class and its "view" files.

  *

  */

 public function vars($vars = array(), $val = '')

 {

  if ($val != '' AND is_string($vars))

  {

   $vars = array($vars => $val);

  }

  $vars = $this->_ci_object_to_array($vars);

  if (is_array($vars) AND count($vars) > 0)

  {

   foreach ($vars as $key => $val)

   {

    $this->_ci_cached_vars[$key] = $val;

   }

  }

 }

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

 /**

  * 检查并获取变量

  */

 public function get_var($key)

 {

  return isset($this->_ci_cached_vars[$key]) ? $this->_ci_cached_vars[$key] : NULL;

 }

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

 /**

  * 加载helper

  */

 public function helper($helpers = array())

 {

  foreach ($this->_ci_prep_filename($helpers, '_helper') as $helper)

  {

   if (isset($this->_ci_helpers[$helper]))

   {

    continue;

   }

   $ext_helper = APPPATH.'helpers/'.config_item('subclass_prefix').$helper.'.php';

   // 如果是扩展helper的话

   if (file_exists($ext_helper))

   {

    $base_helper = BASEPATH.'helpers/'.$helper.'.php';

    if ( ! file_exists($base_helper))

    {

     show_error('Unable to load the requested file: helpers/'.$helper.'.php');

    }

    include_once($ext_helper);

    include_once($base_helper);

    $this->_ci_helpers[$helper] = TRUE;

    log_message('debug', 'Helper loaded: '.$helper);

    continue;

   }

   // 如果不是扩展helper，helper路径中加载helper

   foreach ($this->_ci_helper_paths as $path)

   {

    if (file_exists($path.'helpers/'.$helper.'.php'))

    {

     include_once($path.'helpers/'.$helper.'.php');

     $this->_ci_helpers[$helper] = TRUE;

     log_message('debug', 'Helper loaded: '.$helper);

     break;

    }

   }

   // 如果该helper还没加载成功的话，说明加载helper失败

   if ( ! isset($this->_ci_helpers[$helper]))

   {

    show_error('Unable to load the requested file: helpers/'.$helper.'.php');

   }

  }

 }

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

 /**

  * 可以看到helpers调用也是上面的helper,只是helpers的别名而已

  */

 public function helpers($helpers = array())

 {

  $this->helper($helpers);

 }

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

 /**

  * 加载language文件

  */

 public function language($file = array(), $lang = '')

 {

  $CI =& get_instance();

  if ( ! is_array($file))

  {

   $file = array($file);

  }

  foreach ($file as $langfile)

  {

   $CI->lang->load($langfile, $lang);

  }

 }

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

 /**

  * 加载配置文件

  */

 public function config($file = '', $use_sections = FALSE, $fail_gracefully = FALSE)

 {

  $CI =& get_instance();

  $CI->config->load($file, $use_sections, $fail_gracefully);

 }

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

 /**

  * Driver

  *

  * 加载 driver library

  */

 public function driver($library = '', $params = NULL, $object_name = NULL)

 {

  if ( ! class_exists('CI_Driver_Library'))

  {

   // we aren't instantiating an object here, that'll be done by the Library itself

   require BASEPATH.'libraries/Driver.php';

  }

  if ($library == '')

  {

   return FALSE;

  }

  // We can save the loader some time since Drivers will *always* be in a subfolder,

  // and typically identically named to the library

  if ( ! strpos($library, '/'))

  {

   $library = ucfirst($library).'/'.$library;

  }

  return $this->library($library, $params, $object_name);

 }

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

 /**

  * 添加 Package 路径

  *

  * 把package路径添加到库，模型，助手，配置路径

  */

 public function add_package_path($path, $view_cascade=TRUE)

 {

  $path = rtrim($path, '/').'/';

  array_unshift($this->_ci_library_paths, $path);

  array_unshift($this->_ci_model_paths, $path);

  array_unshift($this->_ci_helper_paths, $path);

  $this->_ci_view_paths = array($path.'views/' => $view_cascade) + $this->_ci_view_paths;

  $config =& $this->_ci_get_component('config');

  array_unshift($config->_config_paths, $path);

 }

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

 /**

  * 获取Package Paths，默认不包含BASEPATH

  */

 public function get_package_paths($include_base = FALSE)

 {

  return $include_base === TRUE ? $this->_ci_library_paths : $this->_ci_model_paths;

 }

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

 /**

  * 剔除Package Path

  *

  * Remove a path from the library, model, and helper path arrays if it exists

  * If no path is provided, the most recently added path is removed.

  *

  */

 public function remove_package_path($path = '', $remove_config_path = TRUE)

 {

  $config =& $this->_ci_get_component('config');

  if ($path == '')

  {

   $void = array_shift($this->_ci_library_paths);

   $void = array_shift($this->_ci_model_paths);

   $void = array_shift($this->_ci_helper_paths);

   $void = array_shift($this->_ci_view_paths);

   $void = array_shift($config->_config_paths);

  }

  else

  {

   $path = rtrim($path, '/').'/';

   foreach (array('_ci_library_paths', '_ci_model_paths', '_ci_helper_paths') as $var)

   {

    if (($key = array_search($path, $this->{$var})) !== FALSE)

    {

     unset($this->{$var}[$key]);

    }

   }

   if (isset($this->_ci_view_paths[$path.'views/']))

   {

    unset($this->_ci_view_paths[$path.'views/']);

   }

   if (($key = array_search($path, $config->_config_paths)) !== FALSE)

   {

    unset($config->_config_paths[$key]);

   }

  }

  // 保证应用默认的路径依然存在

  $this->_ci_library_paths = array_unique(array_merge($this->_ci_library_paths, array(APPPATH, BASEPATH)));

  $this->_ci_helper_paths = array_unique(array_merge($this->_ci_helper_paths, array(APPPATH, BASEPATH)));

  $this->_ci_model_paths = array_unique(array_merge($this->_ci_model_paths, array(APPPATH)));

  $this->_ci_view_paths = array_merge($this->_ci_view_paths, array(APPPATH.'views/' => TRUE));

  $config->_config_paths = array_unique(array_merge($config->_config_paths, array(APPPATH)));

 }

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

 /**

  * Loader

  *

  * This function is used to load views and files.

  * Variables are prefixed with _ci_ to avoid symbol collision with

  * variables made available to view files

  *

  * @param array

  * @return void

  */

 protected function _ci_load($_ci_data)

 {

  // Set the default data variables

  foreach (array('_ci_view', '_ci_vars', '_ci_path', '_ci_return') as $_ci_val)

  {

   $$_ci_val = ( ! isset($_ci_data[$_ci_val])) ? FALSE : $_ci_data[$_ci_val];

  }

  $file_exists = FALSE;

                //如果$_ci_path不为空，则说明当前要加载普通文件。Loader::file才会有path

  if ($_ci_path != '')

  {

   $_ci_x = explode('/', $_ci_path);

   $_ci_file = end($_ci_x);

  }

  else

  {

   $_ci_ext = pathinfo($_ci_view, PATHINFO_EXTENSION);

   $_ci_file = ($_ci_ext == '') ? $_ci_view.'.php' : $_ci_view;

   foreach ($this->_ci_view_paths as $view_file => $cascade)

   {

    if (file_exists($view_file.$_ci_file))

    {

     $_ci_path = $view_file.$_ci_file;

     $file_exists = TRUE;

     break;

    }

    if ( ! $cascade)

    {

     break;

    }

   }

  }

                //view文件不存在则会报错

  if ( ! $file_exists && ! file_exists($_ci_path))

  {

   show_error('Unable to load the requested file: '.$_ci_file);

  }

  // 把CI的所有属性都传递给loader，view中$this指的是loader

  $_ci_CI =& get_instance();

  foreach (get_object_vars($_ci_CI) as $_ci_key => $_ci_var)

  {

   if ( ! isset($this->$_ci_key))

   {

    $this->$_ci_key =& $_ci_CI->$_ci_key;

   }

  }

  /*

   * Extract and cache variables

   *

   * You can either set variables using the dedicated $this->load_vars()

   * function or via the second parameter of this function. We'll merge

   * the two types and cache them so that views that are embedded within

   * other views can have access to these variables.

   */

  if (is_array($_ci_vars))

  {

   $this->_ci_cached_vars = array_merge($this->_ci_cached_vars, $_ci_vars);

  }

  extract($this->_ci_cached_vars);

  /*

   * 将视图内容放到缓存区

   *

   */

  ob_start();

  // 支持短标签

  if ((bool) @ini_get('short_open_tag') === FALSE AND config_item('rewrite_short_tags') == TRUE)

  {

   echo eval('?>'.preg_replace("/;*\s*\?>/", "; ?>", str_replace('<?=', '<?php echo ', file_get_contents($_ci_path))));

  }

  else

  {

   include($_ci_path); // include() vs include_once() allows for multiple views with the same name

  }

  log_message('debug', 'File loaded: '.$_ci_path);

  // 是否直接返回view数据

  if ($_ci_return === TRUE)

  {

   $buffer = ob_get_contents();

   @ob_end_clean();

   return $buffer;

  }

  //当前这个视图文件是被另一个视图文件通过$this->view()方法引入，即视图文件嵌入视图文件

  if (ob_get_level() > $this->_ci_ob_level + 1)

  {

   ob_end_flush();

  }

  else

  {       ////把缓冲区的内容交给Output组件并清空关闭缓冲区。

   $_ci_CI->output->append_output(ob_get_contents());

   @ob_end_clean();

  }

 }

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

 /**

  * 加载类

  */

 protected function _ci_load_class($class, $params = NULL, $object_name = NULL)

 {

  // 去掉.php和两端的/获取的$class就是类名或目录名+类名

  $class = str_replace('.php', '', trim($class, '/'));

  // CI允许dir/filename方式

  $subdir = '';

  if (($last_slash = strrpos($class, '/')) !== FALSE)

  {

   // 目录

   $subdir = substr($class, 0, $last_slash + 1);

   // 文件名

   $class = substr($class, $last_slash + 1);

  }

  // 允许加载的类名首字母大写或全小写

  foreach (array(ucfirst($class), strtolower($class)) as $class)

  {

   $subclass = APPPATH.'libraries/'.$subdir.config_item('subclass_prefix').$class.'.php';

   // 是否是扩展类

   if (file_exists($subclass))

   {

    $baseclass = BASEPATH.'libraries/'.ucfirst($class).'.php';

    if ( ! file_exists($baseclass))

    {

     log_message('error', "Unable to load the requested class: ".$class);

     show_error("Unable to load the requested class: ".$class);

    }

    // Safety:  Was the class already loaded by a previous call?

    if (in_array($subclass, $this->_ci_loaded_files))

    {

     // Before we deem this to be a duplicate request, let's see

     // if a custom object name is being supplied.  If so, we'll

     // return a new instance of the object

     if ( ! is_null($object_name))

     {

      $CI =& get_instance();

      if ( ! isset($CI->$object_name))

      {

       return $this->_ci_init_class($class, config_item('subclass_prefix'), $params, $object_name);

      }

     }

     $is_duplicate = TRUE;

     log_message('debug', $class." class already loaded. Second attempt ignored.");

     return;

    }

    include_once($baseclass);

    include_once($subclass);

    $this->_ci_loaded_files[] = $subclass;

                                //实例化类

    return $this->_ci_init_class($class, config_item('subclass_prefix'), $params, $object_name);

   }

   // 如果不是扩展，和上面类似

   $is_duplicate = FALSE;

   foreach ($this->_ci_library_paths as $path)

   {

    $filepath = $path.'libraries/'.$subdir.$class.'.php';

    // Does the file exist?  No?  Bummer...

    if ( ! file_exists($filepath))

    {

     continue;

    }

    // Safety:  Was the class already loaded by a previous call?

    if (in_array($filepath, $this->_ci_loaded_files))

    {

     // Before we deem this to be a duplicate request, let's see

     // if a custom object name is being supplied.  If so, we'll

     // return a new instance of the object

     if ( ! is_null($object_name))

     {

      $CI =& get_instance();

      if ( ! isset($CI->$object_name))

      {

       return $this->_ci_init_class($class, '', $params, $object_name);

      }

     }

     $is_duplicate = TRUE;

     log_message('debug', $class." class already loaded. Second attempt ignored.");

     return;

    }

    include_once($filepath);

    $this->_ci_loaded_files[] = $filepath;

    return $this->_ci_init_class($class, '', $params, $object_name);

   }

  } // END FOREACH

  // 如果还没有找到该class，最后的尝试是该class会不会在同名的子目录下

  if ($subdir == '')

  {

   $path = strtolower($class).'/'.$class;

   return $this->_ci_load_class($path, $params);

  }

  // 加载失败，报错

  if ($is_duplicate == FALSE)

  {

   log_message('error', "Unable to load the requested class: ".$class);

   show_error("Unable to load the requested class: ".$class);

  }

 }

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

 /**

  * 实例化已经加载的类

  */

 protected function _ci_init_class($class, $prefix = '', $config = FALSE, $object_name = NULL)

 {

  // 是否有类的配置信息

  if ($config === NULL)

  {

   // Fetch the config paths containing any package paths

   $config_component = $this->_ci_get_component('config');

   if (is_array($config_component->_config_paths))

   {

    // Break on the first found file, thus package files

    // are not overridden by default paths

    foreach ($config_component->_config_paths as $path)

    {

     // We test for both uppercase and lowercase, for servers that

     // are case-sensitive with regard to file names. Check for environment

     // first, global next

     if (defined('ENVIRONMENT') AND file_exists($path .'config/'.ENVIRONMENT.'/'.strtolower($class).'.php'))

     {

      include($path .'config/'.ENVIRONMENT.'/'.strtolower($class).'.php');

      break;

     }

     elseif (defined('ENVIRONMENT') AND file_exists($path .'config/'.ENVIRONMENT.'/'.ucfirst(strtolower($class)).'.php'))

     {

      include($path .'config/'.ENVIRONMENT.'/'.ucfirst(strtolower($class)).'.php');

      break;

     }

     elseif (file_exists($path .'config/'.strtolower($class).'.php'))

     {

      include($path .'config/'.strtolower($class).'.php');

      break;

     }

     elseif (file_exists($path .'config/'.ucfirst(strtolower($class)).'.php'))

     {

      include($path .'config/'.ucfirst(strtolower($class)).'.php');

      break;

     }

    }

   }

  }

  if ($prefix == '')

  {       //system下library

   if (class_exists('CI_'.$class))

   {

    $name = 'CI_'.$class;

   }

   elseif (class_exists(config_item('subclass_prefix').$class))

   {       //扩展library

    $name = config_item('subclass_prefix').$class;

   }

   else

   {

    $name = $class;

   }

  }

  else

  {

   $name = $prefix.$class;

  }

  // Is the class name valid?

  if ( ! class_exists($name))

  {

   log_message('error', "Non-existent class: ".$name);

   show_error("Non-existent class: ".$class);

  }

  // Set the variable name we will assign the class to

  // Was a custom class name supplied?  If so we'll use it

  $class = strtolower($class);

  if (is_null($object_name))

  {

   $classvar = ( ! isset($this->_ci_varmap[$class])) ? $class : $this->_ci_varmap[$class];

  }

  else

  {

   $classvar = $object_name;

  }

  // Save the class name and object name

  $this->_ci_classes[$class] = $classvar;

  // 将初始化的类的实例给CI超级句柄

  $CI =& get_instance();

  if ($config !== NULL)

  {

   $CI->$classvar = new $name($config);

  }

  else

  {

   $CI->$classvar = new $name;

  }

 }

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

 /**

  * 自动加载器

         * 

         * autoload.php配置的自动加载文件有：

         *  | 1. Packages

            | 2. Libraries

            | 3. Helper files

            | 4. Custom config files

            | 5. Language files

            | 6. Models

  */

 private function _ci_autoloader()

 {

  if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/autoload.php'))

  {

   include(APPPATH.'config/'.ENVIRONMENT.'/autoload.php');

  }

  else

  {

   include(APPPATH.'config/autoload.php');

  }

  if ( ! isset($autoload))

  {

   return FALSE;

  }

  // 自动加载packages,也就是将package_path加入到library，model，helper，config

  if (isset($autoload['packages']))

  {

   foreach ($autoload['packages'] as $package_path)

   {

    $this->add_package_path($package_path);

   }

  }

  // 加载config文件

  if (count($autoload['config']) > 0)

  {

   $CI =& get_instance();

   foreach ($autoload['config'] as $key => $val)

   {

    $CI->config->load($val);

   }

  }

  // 加载helper和language

  foreach (array('helper', 'language') as $type)

  {

   if (isset($autoload[$type]) AND count($autoload[$type]) > 0)

   {

    $this->$type($autoload[$type]);

   }

  }

  // 这个好像是为了兼容以前版本的

  if ( ! isset($autoload['libraries']) AND isset($autoload['core']))

  {

   $autoload['libraries'] = $autoload['core'];

  }

  // 加载libraries

  if (isset($autoload['libraries']) AND count($autoload['libraries']) > 0)

  {

   // 加载db

   if (in_array('database', $autoload['libraries']))

   {

    $this->database();

    $autoload['libraries'] = array_diff($autoload['libraries'], array('database'));

   }

   // 加载所有其他libraries

   foreach ($autoload['libraries'] as $item)

   {

    $this->library($item);

   }

  }

  // Autoload models

  if (isset($autoload['model']))

  {

   $this->model($autoload['model']);

  }

 }

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

 /**

  * 返回由对象属性组成的关联数组

  */

 protected function _ci_object_to_array($object)

 {

  return (is_object($object)) ? get_object_vars($object) : $object;

 }

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

 /**

  * 获取CI某个组件的实例

  */

 protected function &_ci_get_component($component)

 {

  $CI =& get_instance();

  return $CI->$component;

 }

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

 /**

  * 处理文件名，这个函数主要是返回正确文件名

  */

 protected function _ci_prep_filename($filename, $extension)

 {

  if ( ! is_array($filename))

  {

   return array(strtolower(str_replace('.php', '', str_replace($extension, '', $filename)).$extension));

  }

  else

  {

   foreach ($filename as $key => $val)

   {

    $filename[$key] = strtolower(str_replace('.php', '', str_replace($extension, '', $val)).$extension);

   }

   return $filename;

  }

 }

}