CI framework source code reading---------Router.php_PHP tutorial

[php]  

/** 

 * 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 

 */  

  

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

  

/** 

 * Router Class 

 * 

 * Parses URIs and determines routing 

 * 

 * @package     CodeIgniter 

 * @subpackage  Libraries 

 * @author      ExpressionEngine Dev Team 

 * @category    Libraries 

 * @link        http://codeigniter.com/user_guide/general/routing.html 

 */  

class CI_Router {  

  

    /** 

     * Config class 

     * 配置 

     * @var object 

     * @access public 

     */  

    var $config;  

    /**

* List of routes

* Route list, value comes from APPPATH/config/route.php

* @var array

* @access public

*/  

    var $routes         = array();  

    /**

* List of error routes

* Error routing list

* @var array

* @access public

*/  

    var $error_routes   = array();  

    /** 

     * Current class name 

     * URI中的Controller 

     * @var string 

     * @access public 

     */  

    var $class          = '';  

    /**

* Current method name

* The function called is displayed in the URI, the default is index()

* @var string

* @access public

*/  

    var $method         = 'index';  

    /**

* Sub-directory that contains the requested controller class

* The actual directory information in the URI

* @var string

* @access public

*/  

    var $directory      = '';  

    /**

* Default controller (and method if specific)

* Default controller

* @var string

* @access public

*/  

    var $default_controller;  

  

    /**

* Constructor

*

* Runs the route mapping function.

* Load and instantiate the config class and URI class

*/  

    function __construct()  

    {  

        $this->config =& load_class('Config', 'core');  

$this->uri =& load_class('URI', 'core');

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

}

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

/**

* Set the route mapping

*

* This function determines what should be served based on the URI request,

* as well as any "routes" that have been set in the routing config file.

* Set the default routing information. If there is no controller information, load the default controller according to the settings of routes.php,

*

* @access private

* @return void

*/

function _set_routing()

{

// Are query strings enabled in the config file? Normally CI doesn't utilize query strings

// since URI segments are more search-engine friendly, but they can optionally be used.

// If this feature is enabled, we will gather the directory/class/method a little differently

// If the project allows the query_strings format and requests the controller via $_GET, it will be routed in the query_string format

// Why do we need to judge whether the controller is specified by get method above?

// Actually it’s because if query_string request routing is allowed, but it is not configured under APPPATH/config/config.php

// Controller_trigger, function_trigger, directory_trigger cannot be used in query_strings form

// At this time, we will still use the "segment" form.

$segments = array();

if ($this->config->item('enable_query_strings') === TRUE AND isset($_GET[$this->config->item('controller_trigger')]))

{

                                        //Get the variable names passed by the directory name, control name and method name. These three items are defined in config/config.php.

if (isset($_GET[$this->config->item('directory_trigger')]))

                                                                 

$this->set_directory(trim($this->uri->_filter_uri($_GET[$this->config->item('directory_trigger')])));

$segments[] = $this->fetch_directory();

      }  

if (isset($_GET[$this->config->item('controller_trigger')]))

                                                                 

                     $this->set_class(trim($this->uri->_filter_uri($_GET[$this->config->item('controller_trigger')])));

$segments[] = $this->fetch_class();

      }  

if (isset($_GET[$this->config->item('function_trigger')]))

                                                                 

$this->set_method(trim($this->uri->_filter_uri($_GET[$this->config->item('function_trigger')])));

$segments[] = $this->fetch_method();

      }  

} }

// Load the routes.php file.

// Load routes.php under APPPATH according to the current environment

if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/routes.php'))

{

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

} }

elseif (is_file(APPPATH.'config/routes.php'))

{

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

} }

// The following $route variable is defined in routes.php to set the default controller and default 404 page

$this->routes = ( ! isset($route) OR ! is_array($route)) ? array() : $route;

Unset ($ Route); // Drain it after use, dismantle the bridge across the river, and no mercy.

// Set the default controller so we can display it in the event

// the URI doesn't correlated to a valid controller.

// Set the default controller based on the configuration information just now. If not, it will be FLASE.

$this->default_controller = ( ! isset($this->routes['default_controller']) OR $this->routes['default_controller'] == '') ? FALSE : strtolower($this ->routes['default_controller']);

// Were there any query string segments? If so, we'll validate them and bail out since we're done.

// Verify whether any of the directory name, control name and method name is obtained through query string.

// If you get it, directly determine the route and return

if (count($segments) > 0)

{

// Determine and set the route.

Return $ this- & gt; _Validate_request ($ segments);

} }

// Fetch the complete URI string

// The purpose of this function is to detect and process the uri and get the information we need to determine the routing (such as index.php/index/welcome/1)

// Put the string index/welcome/1) into $this->uri->uri_string.

$this->uri->_fetch_uri_string();

// Is there a URI string? If not, the default controller specified in the "routes" file will be shown.

// If uri_string is empty, then set the route to the default.

/*if ($this->uri->uri_string == '')

{

return $this->_set_default_controller();

}*/

// Do we need to remove the URL suffix?

// Remove the URI suffix, because CI allows adding a suffix after the uri, but it is actually redundant for us to find routes and will have an impact, so remove it first.

$this->uri->_remove_url_suffix();

// Compile compile the segments into an array

// Split the uri into regular segments, filter each segment, and store it in $this->segments[]

$this->uri->_explode_segments();

// Parse any custom routing that may exist

// Process routing, set APPPATH/config/routes.php according to routing

$this->_parse_routes();

// Re-index the segment array so that it starts with 1 rather than 0

// Set the uri segment index to start from 1

$this->uri->_reindex_segments();

}

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

/**

* Set the default controller

* Set default controller

* @access private

* @return void

*/

function _set_default_controller()

{

// Read the default controller name from the configuration file in the Router::_set_routing() function, if not there will be FALSE

// Line 158 of this file

if ($this->default_controller === FALSE)

{

show_error("Unable to determine what should be displayed. A default route has not been specified in the routing file.");

} }

// Is the method being specified?

// Determine whether there is a specified method by judging whether $this->default_controller has /.

// If not set as the default method index

if (strpos($this->default_controller, '/') !== FALSE)

{

$x = explode('/', $this->default_controller);

$this->set_class($x[0]);

$this->set_method($x[1]);

$this->_set_request($x);

} }

else

{

$this->set_class($this->default_controller);

$this->set_method('index');

$this->_set_request(array($this->default_controller, 'index'));

} }

// re-index the routed segments array so it starts with 1 rather than 0

                                     // Re-index the segment so that the outgoing segments are saved starting with the subscript 1.

$this->uri->_reindex_segments();

log_message('debug', "No URI present. Default controller set.");

}

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

/**

* Set the Route

* Set routing

* This function takes take, prepare action an array of URI segments as

* input, and sets the current class/method

*

* @access private

* @param array

* @param bool

* @return void

*/

function _set_request($segments = array())

{

// The function of Router::_validate_request() is to detect and find a correctly existing route and determine it

$segments = $this->_validate_request($segments);

// This function is called by _set_default_controller. If you look at lines 216-230, you will find that $segments will definitely not be empty.

// Then the following two sentences may be to prevent this method from being called in other places and calling _set_default_controller() when the parameter is empty

// If you call it back, $segments will not be empty, because it is impossible to set routing when $segments is empty.

if (count($segments) == 0)

{

Return $ this- & gt; _set_default_Controller ();

} }

// Set the class name which is also the directory name

$this->set_class($segments[0]);

// If the method name exists, set it. If it does not exist, set it to index

if (isset($segments[1]))

{

// A standard request method

$this->set_method($segments[1]);

} }

else

{

                          // This lets the "routed" segment array identify that the default  

// index method is being used.

$segments[1] = 'index';

} }

// Update our "routed" segment array to contain the segments.

// Note: If there is no custom routing, this array will be

// identical to $this->uri->segments

// Update the segment array of the route. If there is no custom route here, it will be the same as $this->uri->segments

$this->uri->rsegments = $segments;

}

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

/**

* Validates validates the supplied segments. Attempts attempt to determine the path to

* the controller.

* Validates the provided segment and attempts to determine the path to the controller

* @access private

* @param array

* @return array

*/

function _validate_request($segments)

{

// ? ? ? ? ? ? ? ? ? ? ? ? ? ?

if (count($segments) == 0)

{

return $segments;

} }

// Does the requested controller exist in the root folder?

// Determine whether $segments[0] exists in the php file under the APPPATH/controllers/ folder

if (file_exists(APPPATH.'controllers/'.$segments[0].'.php'))

{

return $segments;

} }

// Is the controller in a sub-folder?

// Whether $segments[0] is a subdirectory under APPPATH/controllers

if (is_dir(APPPATH.'controllers/'.$segments[0]))

{

// Set the directory and remove it from the segment array

                                                                                                    // If it is indeed a directory, then the directory part of the route can be determined. Set directory

$this->set_directory($segments[0]);

                      // Remove the directory part. Further route search.

$segments = array_slice($segments, 1);

                                                                     

// If there are other paragraphs in addition to the directory in the URI request, it means that there is a specified controller.

if (count($segments) > 0)

                                                                 

                                                                                                                                                                                                 

// Determine the request's $ segments [0] whether the app file in the Appppath/Controller/subdirectory

                    if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].'.php'))

                                                                         

// There are two ways to report an error, one is default, and the other is self -determined.

                                                                                                                                                                                                                        // The following 404_override is a route defined in config/routes.php that cannot be found

// The default processing controller at that time, if we are defined, we call it.

                  if ( ! emptyempty($this->routes['404_override']))  

                                                                                 

                                                         

                                                                                                                                                                                                                        $x = explode('/', $this->routes['404_override']);

// Remove the directory part of the route that I just set, because the route is now the 404 route we defined.

$this->set_directory('');

// It can be seen here that the 404 routing we define is not allowed to be placed in a certain directory, and we can only be placed directly in controllers/below

                                                                                                                                                                 

                                                                                        $this->set_method(isset($x[1]) ? $x[1] : 'index');

                        return $x;                                          

                                                                       

              else  

                                                                                 

                                                                                                                                                                                                                                                                                                 

show_404($this->fetch_directory().$segments[0]);

                                                                       

        }  

      }  

        else  

                                                                 

// If we only have a directory in the URI request, we will come to this

                       // Is the method being specified in the route?

// The judgment below is just judging the $ this-& gt; default_controller. Is there any specified method?

              if (strpos($this->default_controller, '/') !== FALSE)

                                                                         

                                                                                                                                                                             

$this->set_class($x[0]);

                    $this->set_method($x[1]);  

                }  

                else  

                {  

                    $this->set_class($this->default_controller);  

                    $this->set_method('index');  

                }  

  

                // Does the default controller exist in the sub-folder?  

                // 判断APPPATH/controllers/目录/下面是否存在默认的方法  

                if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$this->default_controller.'.php'))  

                {  

                    $this->directory = '';  

                    return array();  

                }  

  

            }  

  

            return $segments;  

        }  

  

  

        // If we've gotten 达到 this far 遥远的 it means that the URI does not correlate 使相关联 to a valid  

        // controller class.  We will now see if there is an override  

        // 来到这里，就说明了，即找不到controllers/下相应的控制器，也找不到这样的目录。那就报错咯。  

        if ( ! emptyempty($this->routes['404_override']))  

        {  

            $x = explode('/', $this->routes['404_override']);  

  

            $this->set_class($x[0]);  

            $this->set_method(isset($x[1]) ? $x[1] : 'index');  

  

            return $x;  

        }  

  

  

        // Nothing else to do at this point but show a 404  

        // 展示一个404页面  

        show_404($segments[0]);  

    }  

  

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

  

    /**

* Parse Routes

* Parse route

* This function matches any routes that may exist in

* the config/routes.php file against, against the URI to

* determine decision, determination if the class/method need to be remapped. Redraw the map

*

* @access private

* @return void

*/  

    function _parse_routes()  

    {  

        // Turn the segment array into a URI string  

        // 将segments数组转为uri字符串的形式  

        $uri = implode('/', $this->uri->segments);  

  

        // Is there a literal 文字的，字面的 match?  If so we're done  

        // 如果这个uri是routes.php中定义的那么。。。。。  

        if (isset($this->routes[$uri]))  

        {  

Return $ this-& gt; _Set_request (explode ('/', $ this-& gt; routes [$ uri]));

} }

// Loop through the route array looking for wild-cards

foreach ($this->routes as $key => $val)

{

// Convert Wild-CARDS To Regex Using the pass to make a regular conversion

// If the $ key contains: Any convert to.+,: Num convert to [0-9]+

$key = str_replace(':any', '.+', str_replace(':num', '[0-9]+', $key));

// Does the RegEx match? Perform regular matching

                                                                                                                                                                                                                        

                                                // To match. For example

                                                                                                                                                                                                    $route['show:any:num'] = 'anynum';                                      

// With these two configurations, we can match a uri like showaa123 to its corresponding value which is anynum

if (preg_match('#^'.$key.'$#', $uri))

                                                                 

                                                       

                                                                                                                                                                                                                                                             // Do we have a back-reference? If there is $ in $val and there is (

in $key

                                     // I don’t understand the function of this if. . . Waiting for rescue by experts

                                                                                                                                                                                                                                                                            to

                if (strpos($val, '$') !== FALSE AND strpos($key, '(') !== FALSE)

                                                                         

// Replace the characters in the URI to the $ value

$val = preg_replace('#^'.$key.'$#', $val, $uri);

        }  

Return $ this- & gt; _Set_request (explode ('/', $ value));

      }  

} }

// If we got this far it means we didn't encounter a

// matching route so we'll set the site default route

// If we get this far, it means we didn’t encounter a matching route

// So we will set the website default route

$this->_set_request($this->uri->segments);

}

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

/** 

     * Set the class name 

     * 

     * @access  public 

     * @param   string 

     * @return  void 

     */

function set_class($class)

{

$this->class = str_replace(array('/', '.'), '', $class);

}

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

/** 

     * Fetch the current class 

     * 

     * @access  public 

     * @return  string 

     */

function fetch_class()

{

return $this->class;

    }  

  

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

  

    /** 

     *  Set the method name 

     * 

     * @access  public 

     * @param   string 

     * @return  void 

     */  

    function set_method($method)  

    {  

        $this->method = $method;  

    }  

  

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

  

    /** 

     *  Fetch the current method 

     * 

     * @access  public 

     * @return  string 

     */  

    function fetch_method()  

    {  

        if ($this->method == $this->fetch_class())  

        {  

            return 'index';  

        }  

  

        return $this->method;  

    }  

  

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

  

    /** 

     *  Set the directory name 

     * 

     * @access  public 

     * @param   string 

     * @return  void 

     */  

    function set_directory($dir)  

    {  

        $this->directory = str_replace(array('/', '.'), '', $dir).'/';  

    }  

  

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

  

    /** 

     *  Fetch the sub-directory (if any) that contains the requested controller class 

     * 

     * @access  public 

     * @return  string 

     */  

    function fetch_directory()  

    {  

        return $this->directory;  

    }  

  

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

  

    /**

* Set the controller overrides

* Controller overrides

* This function can cover directories, controllers, and methods again.

* @access public

* @param array

* @return null

*/  

    function _set_overrides($routing)  

    {  

        if ( ! is_array($routing))  

        {  

            return;  

        }  

  

        if (isset($routing['directory']))  

        {  

            $this->set_directory($routing['directory']);  

        }  

  

        if (isset($routing['controller']) AND $routing['controller'] != '')  

        {  www.2cto.com

            $this->set_class($routing['controller']);  

        }  

  

        if (isset($routing['function']))  

        {  www.2cto.com

            $routing['function'] = ($routing['function'] == '') ? 'index' : $routing['function'];  

            $this->set_method($routing['function']);  

        }  

    }  

  

  

}  

// END Router Class  

  

/* End of file Router.php */  

/* Location: ./system/core/Router.php */  

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