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CI framework source code reading---------Router.php_PHP tutorial
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- 2016-07-14 10:09:16882browse
[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')]))
$this->set_class(trim($this->uri->_filter_uri($_GET[$this->config->item('controller_trigger')])));
$segments[] = $this->fetch_class();
}
if (isset($_GET[$this->config->item('function_trigger')]))
// 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);
// 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
return $x;
else
show_404($this->fetch_directory().$segments[0]);
// 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]+', $key));
// Does the RegEx match? Perform regular matching
// With these two configurations, we can match a uri like showaa123 to its corresponding value which is anynum
if (preg_match('#^'.$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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