yii framework source code analysis for creating controller code

The url path 1 using the yii framework looks like hostname/? r = xxxx xxxx/xxxx & sdfs = dsfdsf

We can see that controller in protected directory is sometimes used, and controller in module is sometimes used. For details, please refer to the following analysis:

The following code excerpt from yii framework Yiiroot core code % % / framework web/CWebApplication php

 
================================================================================================= 
//1.runController Is to perform 1 a controller The method of ,$route is $_GET['r'] 
public function runController($route) 
{ 
// I'm going to call createController Go to create 1 a controller Example, so to speak createController Is to choose controller The key to  
if(($ca=$this->createController($route))!==null) 
{ 
list($controller,$actionID)=$ca; 
$oldController=$this->_controller; 
$this->_controller=$controller; 
$controller->init(); 
$controller->run($actionID); 
$this->_controller=$oldController; 
} 
else 
throw new CHttpException(404,Yii::t('yii','Unable to resolve the request "{route}".', 
array('{route}'=>$route===''?$this->defaultController:$route))); 
} 
================================================================================================== 
//2. So let's analyze createController, So let's say we're visiting route is site/contact 
public function createController($route,$owner=null) 
{ 
// The first time I enter this function, $owner Parameter is null  
if($owner===null) 
$owner=$this; 
// if $route Parameter is not included / , then use the default controller 
if(($route=trim($route,'/'))==='') 
$route=$owner->defaultController; 
$caseSensitive=$this->getUrlManager()->caseSensitive; 
// To be able to fully run the following loop, give $route After it 1 a / 
$route.='/'; 
// will / The location is saved at $pos In the  
while(($pos=strpos($route,'/'))!==false) 
{ 
//$id It's the first half, which is site 
$id=substr($route,0,$pos); 
if(!preg_match('/^\w+$/',$id)) 
return null; 
if(!$caseSensitive) 
$id=strtolower($id); 
//$route Into the second half, which is contact 
$route=(string)substr($route,$pos+1); 
//controller Root or subdirectory prefix  
if(!isset($basePath)) // first segment 
{ 
// First entry, $owner Is null without this member variable  
// Not first entry or $owner There are values, and it's possible that this member variable is set. See also CWebModule class  
if(isset($owner->controllerMap[$id])) 
{ 
return array( 
Yii::createComponent($owner->controllerMap[$id],$id,$owner===$this?null:$owner), 
$this->parseActionParams($route), 
); 
} 
// If you can get it through getModule Method to get 1 Two independent modules, then call again createController , and is suitable for site is module Name of the case, reference protected/config/main.php Configuration files, such as yours controller in %webroot%/protected/module/site/controller/ContactController.php 
if(($module=$owner->getModule($id))!==null) 
return $this->createController($route,$module); 
//controller The directory:  
// for CWebApplication , corresponding to config['basePath']( See configuration files )./controller/ , such as yours controller in %webroot%/protected/controller/SiteController.php 
// for CModule Subclass, corresponding to the subclass folder ./contoller/ , such as yours controller in %webroot%/protected/module/site/controller/ContactController.php 
$basePath=$owner->getControllerPath(); 
$controllerID=''; 
} 
else 
$controllerID.='/'; 
$className=ucfirst($id).'Controller'; 
$classFile=$basePath.DIRECTORY_SEPARATOR.$className.'.php'; 
// if $classFile There is, according to what we have above controller Class file path, create class instance  
// If it doesn't exist, it's in a subdirectory controller , continue the loop to find the final controller, Such as your controller in %webroot%/protected/controller/somedir/SiteController 
if(is_file($classFile)) 
{ 
if(!class_exists($className,false)) 
require($classFile); 
if(class_exists($className,false) && is_subclass_of($className,'CController')) 
{ 
$id[0]=strtolower($id[0]); 
return array( 
new $className($controllerID.$id,$owner===$this?null:$owner), 
$this->parseActionParams($route), 
); 
} 
return null; 
} 
$controllerID.=$id; 
$basePath.=DIRECTORY_SEPARATOR.$id; 
} 
}