php优秀框架codeigniter学习系列——CodeIgniter.php概览

1     if ($EXT->call_hook('cache_override') === FALSE && $OUT->_display_cache($CFG, $URI) === TRUE)
2     {
3         exit;
4     }

$SEC =& load_class('Security', 'core');

1 $IN    =& load_class('Input', 'core');

1 /*
2  * ------------------------------------------------------
3  *  Load the Language class
4  * ------------------------------------------------------
5  */
6     $LANG =& load_class('Lang', 'core');

 1     // Load the base controller class
 2     require_once BASEPATH.'core/Controller.php';
 3 
 4     /**
 5      * Reference to the CI_Controller method.
 6      *
 7      * Returns current CI instance object
 8      *
 9      * @return CI_Controller
10      */
11     function &get_instance()
12     {
13         return CI_Controller::get_instance();
14     }
15 
16     if (file_exists(APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php'))
17     {
18         require_once APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php';
19     }

/*
 * ------------------------------------------------------
 *  Sanity checks
 * ------------------------------------------------------
 *
 *  The Router class has already validated the request,
 *  leaving us with 3 options here:
 *
 *    1) an empty class name, if we reached the default
 *       controller, but it didn't exist;
 *    2) a query string which doesn't go through a
 *       file_exists() check
 *    3) a regular request for a non-existing page
 *
 *  We handle all of these as a 404 error.
 *
 *  Furthermore, none of the methods in the app controller
 *  or the loader class can be called via the URI, nor can
 *  controller methods that begin with an underscore.
 */

    $e404 = FALSE;
    $class = ucfirst($RTR->class);
    $method = $RTR->method;

    if (empty($class) OR ! file_exists(APPPATH.'controllers/'.$RTR->directory.$class.'.php'))
    {
        $e404 = TRUE;
    }
    else
    {
        require_once(APPPATH.'controllers/'.$RTR->directory.$class.'.php');

        if ( ! class_exists($class, FALSE) OR $method[0] === '_' OR method_exists('CI_Controller', $method))
        {
            $e404 = TRUE;
        }
        elseif (method_exists($class, '_remap'))
        {
            $params = array($method, array_slice($URI->rsegments, 2));
            $method = '_remap';
        }
        elseif ( ! method_exists($class, $method))
        {
            $e404 = TRUE;
        }
        /**
         * DO NOT CHANGE THIS, NOTHING ELSE WORKS!
         *
         * - method_exists() returns true for non-public methods, which passes the previous elseif//对于私有方法一样会返回true
         * - is_callable() returns false for PHP 4-style constructors, even if there's a __construct()
         * - method_exists($class, '__construct') won't work because CI_Controller::__construct() is inherited
         * - People will only complain if this doesn't work, even though it is documented that it shouldn't.
         *
         * ReflectionMethod::isConstructor() is the ONLY reliable check,
         * knowing which method will be executed as a constructor.
         */
        elseif ( ! is_callable(array($class, $method)))
        {
            $reflection = new ReflectionMethod($class, $method);
            if ( ! $reflection->isPublic() OR $reflection->isConstructor())
            {
                $e404 = TRUE;
            }
        }
    }

    if ($e404)
    {
        if ( ! empty($RTR->routes['404_override']))
        {
            if (sscanf($RTR->routes['404_override'], '%[^/]/%s', $error_class, $error_method) !== 2)
            {
                $error_method = 'index';
            }

            $error_class = ucfirst($error_class);

            if ( ! class_exists($error_class, FALSE))
            {
                if (file_exists(APPPATH.'controllers/'.$RTR->directory.$error_class.'.php'))
                {
                    require_once(APPPATH.'controllers/'.$RTR->directory.$error_class.'.php');
                    $e404 = ! class_exists($error_class, FALSE);
                }
                // Were we in a directory? If so, check for a global override
                elseif ( ! empty($RTR->directory) && file_exists(APPPATH.'controllers/'.$error_class.'.php'))
                {
                    require_once(APPPATH.'controllers/'.$error_class.'.php');
                    if (($e404 = ! class_exists($error_class, FALSE)) === FALSE)
                    {
                        $RTR->directory = '';
                    }
                }
            }
            else
            {
                $e404 = FALSE;
            }
        }

        // Did we reset the $e404 flag? If so, set the rsegments, starting from index 1
        if ( ! $e404)
        {
            $class = $error_class;
            $method = $error_method;

            $URI->rsegments = array(
                1 => $class,
                2 => $method
            );
        }
        else
        {
            show_404($RTR->directory.$class.'/'.$method);
        }
    }

    if ($method !== '_remap')
    {
        $params = array_slice($URI->rsegments, 2);
    }