在建構式這裡，我們再次見識到全域函數 load_class的重要性。
它載入了Config與URI兩個類別。

我們也在這裡見識到CI的固執。
就不能用PHP的require或是include函式嗎？
正因為這樣的dependency，CI框架的內部相依性非常強，幾乎沒有元件可以搬出CI框架之外使用。
舉例來說，你也許覺得這個Router類別很讚，但你無法把它拿去放進你自己撰寫的框架。
若是用require或是include撰寫，把相關的類別一併搬過去就可以了。

// -------------------------------------------------------------------- /** * 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. * * @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 $segments = array(); if ($this->config->item('enable_query_strings') === TRUE AND isset($_GET[$this->config->item('controller_trigger')])) { 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(); } }

CI預設是根據URL區段去呼叫對應的controller跟method，不過它允許你改成query string。
例如：index.php?c=controller&m=method會根據c參數呼叫controller、m參數呼叫method。
注意c跟m這兩個只是預設，可以去config.php修改喔！

// Load the routes.php file. 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'); } $this->routes = ( ! isset($route) OR ! is_array($route)) ? array() : $route; unset($route);

載入routes.php之後，這邊只用一行就確認了$route有被設定並且是陣列。
並且還在例外情況預設了空陣列。

// Set the default controller so we can display it in the event // the URI doesn't correlated to a valid controller. $this->default_controller = ( ! isset($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. if (count($segments) > 0) { return $this->_validate_request($segments); } // Fetch the complete URI string $this->uri->_fetch_uri_string(); // Is there a URI string? If not, the default controller specified in the "routes" file will be shown. if ($this->uri->uri_string == '') { return $this->_set_default_controller(); } // Do we need to remove the URL suffix? $this->uri->_remove_url_suffix(); // Compile the segments into an array $this->uri->_explode_segments(); // Parse any custom routing that may exist $this->_parse_routes(); // Re-index the segment array so that it starts with 1 rather than 0 $this->uri->_reindex_segments(); }

這邊執行一些判斷URL與設定controller/method的動作。
幾乎都在呼叫URL類別的函式。

// -------------------------------------------------------------------- /** * Set the default controller * * @access private * @return void */ function _set_default_controller() { if ($this->default_controller === FALSE) { show_error("Unable to determine what should be displayed. A default route has not been specified in the routing file."); } // Is the method being specified? if (strpos($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 $this->uri->_reindex_segments(); log_message('debug', "No URI present. Default controller set."); }

// -------------------------------------------------------------------- /** * Set the Route * * This function takes 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()) { $segments = $this->_validate_request($segments); if (count($segments) == 0) { return $this->_set_default_controller(); } $this->set_class($segments[0]); if (isset($segments[1])) { // A standard method request $this->set_method($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 $this->uri->rsegments = $segments; }

// -------------------------------------------------------------------- /** * Validates the supplied segments. Attempts to determine the path to * the controller. * * @access private * @param array * @return array */ function _validate_request($segments) { if (count($segments) == 0) { return $segments; } // Does the requested controller exist in the root folder? if (file_exists(APPPATH.'controllers/'.$segments[0].'.php')) { return $segments; } // Is the controller in a sub-folder? if (is_dir(APPPATH.'controllers/'.$segments[0])) { // Set the directory and remove it from the segment array $this->set_directory($segments[0]); $segments = array_slice($segments, 1); if (count($segments) > 0) { // Does the requested controller exist in the sub-folder? if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].'.php')) { if ( ! empty($this->routes['404_override'])) { $x = explode('/', $this->routes['404_override']); $this->set_directory(''); $this->set_class($x[0]); $this->set_method(isset($x[1]) ? $x[1] : 'index'); return $x; } else { show_404($this->fetch_directory().$segments[0]); } } } else { // Is the method being specified in the route? if (strpos($this->default_controller, '/') !== FALSE) { $x = explode('/', $this->default_controller); $this->set_class($x[0]); $this->set_method($x[1]); } else { $this->set_class($this->default_controller); $this->set_method('index'); } // Does the default controller exist in the sub-folder? if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$this->default_controller.'.php')) { $this->directory = ''; return array(); } } return $segments; } // If we've gotten this far it means that the URI does not correlate to a valid // controller class. We will now see if there is an override if ( ! empty($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 $x; } // Nothing else to do at this point but show a 404 show_404($segments[0]); }

// -------------------------------------------------------------------- /** * Parse Routes * * This function matches any routes that may exist in * the config/routes.php file against the URI to * determine if the class/method need to be remapped. * * @access private * @return void */ function _parse_routes() { // Turn the segment array into a URI string $uri = implode('/', $this->uri->segments); // Is there a literal match? If so we're done if (isset($this->routes[$uri])) { return $this->_set_request(explode('/', $this->routes[$uri])); } // Loop through the route array looking for wild-cards foreach ($this->routes as $key => $val) { // Convert wild-cards to RegEx $key = str_replace(':any', '.+', str_replace(':num', '[0-9]+', $key)); // Does the RegEx match? if (preg_match('#^'.$key.'$#', $uri)) { // Do we have a back-reference? if (strpos($val, '$') !== FALSE AND strpos($key, '(') !== FALSE) { $val = preg_replace('#^'.$key.'$#', $val, $uri); } return $this->_set_request(explode('/', $val)); } } // If we got this far it means we didn't encounter a // matching route so we'll set the site 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 * * @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'] != '') { $this->set_class($routing['controller']); } if (isset($routing['function'])) { $routing['function'] = ($routing['function'] == '') ? 'index' : $routing['function']; $this->set_method($routing['function']); } } } // END Router Class /* End of file Router.php */ /* Location: ./system/core/Router.php */