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<?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
 */

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

/**
 * Loader Class
 *
 * Loads views and files
 *
 * @package             CodeIgniter
 * @subpackage  Libraries
 * @author              ExpressionEngine Dev Team
 * @category    Loader
 * @link                http://codeigniter.com/user_guide/libraries/loader.html
 */
class CI_Loader {

        // All these are set automatically. Don't mess with them.
        /**
         * Nesting level of the output buffering mechanism
         *
         * @var int
         * @access protected
         */
        protected $_ci_ob_level;
        /**
         * List of paths to load views from
         *
         * @var array
         * @access protected
         */
        protected $_ci_view_paths               = array();
        /**
         * List of paths to load libraries from
         *
         * @var array
         * @access protected
         */
        protected $_ci_library_paths    = array();
        /**
         * List of paths to load models from
         *
         * @var array
         * @access protected
         */
        protected $_ci_model_paths              = array();
        /**
         * List of paths to load helpers from
         *
         * @var array
         * @access protected
         */
        protected $_ci_helper_paths             = array();
        /**
         * List of loaded base classes
         * Set by the controller class
         *
         * @var array
         * @access protected
         */
        protected $_base_classes                = array(); // Set by the controller class
        /**
         * List of cached variables
         *
         * @var array
         * @access protected
         */
        protected $_ci_cached_vars              = array();
        /**
         * List of loaded classes
         *
         * @var array
         * @access protected
         */
        protected $_ci_classes                  = array();
        /**
         * List of loaded files
         *
         * @var array
         * @access protected
         */
        protected $_ci_loaded_files             = array();
        /**
         * List of loaded models
         *
         * @var array
         * @access protected
         */
        protected $_ci_models                   = array();
        /**
         * List of loaded helpers
         *
         * @var array
         * @access protected
         */
        protected $_ci_helpers                  = array();
        /**
         * List of class name mappings
         *
         * @var array
         * @access protected
         */
        protected $_ci_varmap                   = array('unit_test' => 'unit',
                                                                                        'user_agent' => 'agent');

        /**
         * Constructor
         *
         * Sets the path to the view files and gets the initial output buffering level
         */
        public function __construct()
        {
                $this->_ci_ob_level  = ob_get_level();
                $this->_ci_library_paths = array(APPPATH, BASEPATH);
                $this->_ci_helper_paths = array(APPPATH, BASEPATH);
                $this->_ci_model_paths = array(APPPATH);
                $this->_ci_view_paths = array(APPPATH.'views/'  => TRUE);

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

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

        /**
         * Initialize the Loader
         *
         * This method is called once in CI_Controller.
         *
         * @param       array
         * @return      object
         */
        public function initialize()
        {
                $this->_ci_classes = array();
                $this->_ci_loaded_files = array();
                $this->_ci_models = array();
                $this->_base_classes =& is_loaded();

                $this->_ci_autoloader();

                return $this;
        }

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

        /**
         * Is Loaded
         *
         * A utility function to test if a class is in the self::$_ci_classes array.
         * This function returns the object name if the class tested for is loaded,
         * and returns FALSE if it isn't.
         *
         * It is mainly used in the form_helper -> _get_validation_object()
         *
         * @param       string  class being checked for
         * @return      mixed   class object name on the CI SuperObject or FALSE
         */
        public function is_loaded($class)
        {
                if (isset($this->_ci_classes[$class]))
                {
                        return $this->_ci_classes[$class];
                }

                return FALSE;
        }

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

        /**
         * Class Loader
         *
         * This function lets users load and instantiate classes.
         * It is designed to be called from a user's app controllers.
         *
         * @param       string  the name of the class
         * @param       mixed   the optional parameters
         * @param       string  an optional object name
         * @return      void
         */
        public function library($library = '', $params = NULL, $object_name = NULL)
        {
                if (is_array($library))
                {
                        foreach ($library as $class)
                        {
                                $this->library($class, $params);
                        }

                        return;
                }

                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);
        }

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

        /**
         * Model Loader
         *
         * This function lets users load and instantiate models.
         *
         * @param       string  the name of the class
         * @param       string  name for the model
         * @param       bool    database connection
         * @return      void
         */
        public function model($model, $name = '', $db_conn = FALSE)
        {
                if (is_array($model))
                {
                        foreach ($model as $babe)
                        {
                                $this->model($babe);
                        }
                        return;
                }

                if ($model == '')
                {
                        return;
                }

                $path = '';

                // Is the model in a sub-folder? If so, parse out the filename and path.
                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);

                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();

                        $this->_ci_models[] = $name;
                        return;
                }

                // couldn't find the model
                show_error('Unable to locate the model you have specified: '.$model);
        }

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

        /**
         * Database Loader
         *
         * @param       string  the DB credentials
         * @param       bool    whether to return the DB object
         * @param       bool    whether to enable active record (this allows us to override the config setting)
         * @return      object
         */
        public function database($params = '', $return = FALSE, $active_record = NULL)
        {
                // Grab the super object
                $CI =& get_instance();

                // Do we even need to load the database class?
                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);
        }

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

        /**
         * Load the Utilities Class
         *
         * @return      string
         */
        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();
        }

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

        /**
         * Load View
         *
         * This function is used to load a "view" file.  It has three parameters:
         *
         * 1. The name of the "view" file to be included.
         * 2. An associative array of data to be extracted for use in the view.
         * 3. TRUE/FALSE - whether to return the data or load it.  In
         * some cases it's advantageous to be able to return data so that
         * a developer can process it in some way.
         *
         * @param       string
         * @param       array
         * @param       bool
         * @return      void
         */
        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));
        }

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

        /**
         * Load File
         *
         * This is a generic file loader
         *
         * @param       string
         * @param       bool
         * @return      string
         */
        public function file($path, $return = FALSE)
        {
                return $this->_ci_load(array('_ci_path' => $path, '_ci_return' => $return));
        }

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

        /**
         * Set Variables
         *
         * Once variables are set they become available within
         * the controller class and its "view" files.
         *
         * @param       array
         * @param       string
         * @return      void
         */
        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;
                        }
                }
        }

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

        /**
         * Get Variable
         *
         * Check if a variable is set and retrieve it.
         *
         * @param       array
         * @return      void
         */
        public function get_var($key)
        {
                return isset($this->_ci_cached_vars[$key]) ? $this->_ci_cached_vars[$key] : NULL;
        }

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

        /**
         * Load Helper
         *
         * This function loads the specified helper file.
         *
         * @param       mixed
         * @return      void
         */
        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';

                        // Is this a helper extension request?
                        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;
                        }

                        // Try to load the 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;
                                }
                        }

                        // unable to load the helper
                        if ( ! isset($this->_ci_helpers[$helper]))
                        {
                                show_error('Unable to load the requested file: helpers/'.$helper.'.php');
                        }
                }
        }

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

        /**
         * Load Helpers
         *
         * This is simply an alias to the above function in case the
         * user has written the plural form of this function.
         *
         * @param       array
         * @return      void
         */
        public function helpers($helpers = array())
        {
                $this->helper($helpers);
        }

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

        /**
         * Loads a language file
         *
         * @param       array
         * @param       string
         * @return      void
         */
        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);
                }
        }

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

        /**
         * Loads a config file
         *
         * @param       string
         * @param       bool
         * @param       bool
         * @return      void
         */
        public function config($file = '', $use_sections = FALSE, $fail_gracefully = FALSE)
        {
                $CI =& get_instance();
                $CI->config->load($file, $use_sections, $fail_gracefully);
        }

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

        /**
         * Driver
         *
         * Loads a driver library
         *
         * @param       string  the name of the class
         * @param       mixed   the optional parameters
         * @param       string  an optional object name
         * @return      void
         */
        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);
        }

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

        /**
         * Add Package Path
         *
         * Prepends a parent path to the library, model, helper, and config path arrays
         *
         * @param       string
         * @param       boolean
         * @return      void
         */
        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;

                // Add config file path
                $config =& $this->_ci_get_component('config');
                array_unshift($config->_config_paths, $path);
        }

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

        /**
         * Get Package Paths
         *
         * Return a list of all package paths, by default it will ignore BASEPATH.
         *
         * @param       string
         * @return      void
         */
        public function get_package_paths($include_base = FALSE)
        {
                return $include_base === TRUE ? $this->_ci_library_paths : $this->_ci_model_paths;
        }

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

        /**
         * Remove 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.
         *
         * @param       type
         * @param       bool
         * @return      type
         */
        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]);
                        }
                }

                // make sure the application default paths are still in the array
                $this->_ci_library_paths = array_unique(array_merge($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;

                // Set the path to the requested file
                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;
                                }
                        }
                }

                if ( ! $file_exists && ! file_exists($_ci_path))
                {
                        show_error('Unable to load the requested file: '.$_ci_file);
                }

                // This allows anything loaded using $this->load (views, files, etc.)
                // to become accessible from within the Controller and Model functions.

                $_ci_CI =& get_instance();
                foreach (get_object_vars($_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);

                /*
                 * Buffer the output
                 *
                 * We buffer the output for two reasons:
                 * 1. Speed. You get a significant speed boost.
                 * 2. So that the final rendered template can be
                 * post-processed by the output class.  Why do we
                 * need post processing?  For one thing, in order to
                 * show the elapsed page load time.  Unless we
                 * can intercept the content right before it's sent to
                 * the browser and then stop the timer it won't be accurate.
                 */
                ob_start();

                // If the PHP installation does not support short tags we'll
                // do a little string replacement, changing the short tags
                // to standard PHP echo statements.

                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);

                // Return the file data if requested
                if ($_ci_return === TRUE)
                {
                        $buffer = ob_get_contents();
                        @ob_end_clean();
                        return $buffer;
                }

                /*
                 * Flush the buffer... or buff the flusher?
                 *
                 * In order to permit views to be nested within
                 * other views, we need to flush the content back out whenever
                 * we are beyond the first level of output buffering so that
                 * it can be seen and included properly by the first included
                 * template and any subsequent ones. Oy!
                 *
                 */
                if (ob_get_level() > $this->_ci_ob_level + 1)
                {
                        ob_end_flush();
                }
                else
                {
                        $_ci_CI->output->append_output(ob_get_contents());
                        @ob_end_clean();
                }
        }

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

        /**
         * Load class
         *
         * This function loads the requested class.
         *
         * @param       string  the item that is being loaded
         * @param       mixed   any additional parameters
         * @param       string  an optional object name
         * @return      void
         */
        protected function _ci_load_class($class, $params = NULL, $object_name = NULL)
        {
                // Get the class name, and while we're at it trim any slashes.
                // The directory path can be included as part of the class name,
                // but we don't want a leading slash
                $class = str_replace('.php', '', trim($class, '/'));

                // Was the path included with the class name?
                // We look for a slash to determine this
                $subdir = '';
                if (($last_slash = strrpos($class, '/')) !== FALSE)
                {
                        // Extract the path
                        $subdir = substr($class, 0, $last_slash + 1);

                        // Get the filename from the path
                        $class = substr($class, $last_slash + 1);
                }

                // We'll test for both lowercase and capitalized versions of the file name
                foreach (array(ucfirst($class), strtolower($class)) as $class)
                {
                        $subclass = APPPATH.'libraries/'.$subdir.config_item('subclass_prefix').$class.'.php';

                        // Is this a class extension request?
                        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;

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

                        // Lets search for the requested library file and load it.
                        $is_duplicate = FALSE;
                        foreach ($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

                // One last attempt.  Maybe the library is in a subdirectory, but it wasn't specified?
                if ($subdir == '')
                {
                        $path = strtolower($class).'/'.$class;
                        return $this->_ci_load_class($path, $params);
                }

                // If we got this far we were unable to find the requested class.
                // We do not issue errors if the load call failed due to a duplicate request
                if ($is_duplicate == FALSE)
                {
                        log_message('error', "Unable to load the requested class: ".$class);
                        show_error("Unable to load the requested class: ".$class);
                }
        }

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

        /**
         * Instantiates a class
         *
         * @param       string
         * @param       string
         * @param       bool
         * @param       string  an optional object name
         * @return      null
         */
        protected function _ci_init_class($class, $prefix = '', $config = FALSE, $object_name = NULL)
        {
                // Is there an associated config file for this class?  Note: these should always be lowercase
                if ($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 ($prefix == '')
                {
                        if (class_exists('CI_'.$class))
                        {
                                $name = 'CI_'.$class;
                        }
                        elseif (class_exists(config_item('subclass_prefix').$class))
                        {
                                $name = config_item('subclass_prefix').$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;

                // Instantiate the class
                $CI =& get_instance();
                if ($config !== NULL)
                {
                        $CI->$classvar = new $name($config);
                }
                else
                {
                        $CI->$classvar = new $name;
                }
        }

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

        /**
         * Autoloader
         *
         * The config/autoload.php file contains an array that permits sub-systems,
         * libraries, and helpers to be loaded automatically.
         *
         * @param       array
         * @return      void
         */
        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;
                }

                // Autoload packages
                if (isset($autoload['packages']))
                {
                        foreach ($autoload['packages'] as $package_path)
                        {
                                $this->add_package_path($package_path);
                        }
                }

                // Load any custom config file
                if (count($autoload['config']) > 0)
                {
                        $CI =& get_instance();
                        foreach ($autoload['config'] as $key => $val)
                        {
                                $CI->config->load($val);
                        }
                }

                // Autoload helpers and languages
                foreach (array('helper', 'language') as $type)
                {
                        if (isset($autoload[$type]) AND count($autoload[$type]) > 0)
                        {
                                $this->$type($autoload[$type]);
                        }
                }

                // A little tweak to remain backward compatible
                // The $autoload['core'] item was deprecated
                if ( ! isset($autoload['libraries']) AND isset($autoload['core']))
                {
                        $autoload['libraries'] = $autoload['core'];
                }

                // Load libraries
                if (isset($autoload['libraries']) AND count($autoload['libraries']) > 0)
                {
                        // Load the database driver.
                        if (in_array('database', $autoload['libraries']))
                        {
                                $this->database();
                                $autoload['libraries'] = array_diff($autoload['libraries'], array('database'));
                        }

                        // Load all other libraries
                        foreach ($autoload['libraries'] as $item)
                        {
                                $this->library($item);
                        }
                }

                // Autoload models
                if (isset($autoload['model']))
                {
                        $this->model($autoload['model']);
                }
        }

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

        /**
         * Object to Array
         *
         * Takes an object as input and converts the class variables to array key/vals
         *
         * @param       object
         * @return      array
         */
        protected function _ci_object_to_array($object)
        {
                return (is_object($object)) ? get_object_vars($object) : $object;
        }

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

        /**
         * Get a reference to a specific library or model
         *
         * @param       string
         * @return      bool
         */
        protected function &_ci_get_component($component)
        {
                $CI =& get_instance();
                return $CI->$component;
        }

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

        /**
         * Prep filename
         *
         * This function preps the name of various items to make loading them more reliable.
         *
         * @param       mixed
         * @param       string
         * @return      array
         */
        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;
                }
        }
}

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