yii源码分析1

转载请注明：TheViper http://www.cnblogs.com/TheViper/

本文将对yii中的mvc,路由器，filter,组件机制等最主要的部分进行自己的一点浅析，力求说明自己做一个php mvc不是那么的遥不可及，其实是很简单的。

源码基于yii 1.13,为了方便说明，我对其进行了大量的裁剪，不过还是让他保有上面的那些最重要的功能。裁剪下来，其实没有几个文件了，而且每个文件代码最多100多行，避免因为代码太多而懒得看。

所谓的mvc都是让所有请求从一个地方进去，通过对请求，配置的解析，分发到对应的类方法中。

首先当然是入口文件，index.php.

1 <?php
2 $app = "app";
3 $yii = dirname ( __FILE__ ) . '/framework/yii.php';
4 $config = dirname ( __FILE__ ) . '/app/protected/config/main.php';//载入配置
5 require_once ($yii);
6 Yii::createWebApplication ( $config )->run ();

引入yii.php

1 <?php
2 define ( "VIEWS_DIR", "$app/protected/views/" );
3 define ( "CONTROLLERS_DIR", "$app/protected/controllers/" );
4 require(dirname(__FILE__).'/YiiBase.php');
5 class Yii extends YiiBase
6 {
7 }

原来yii是个空的类啊，去看YiiBase.

  1 <?php
  2 defined ( 'YII_PATH' ) or define ( 'YII_PATH', dirname ( __FILE__ ) );
  3 class YiiBase {
  4     public static $classMap = array ();
  5     public static $enableIncludePath = true;
  6     private static $_aliases = array (
  7             'system' => YII_PATH 
  8     ); // alias => path
  9     private static $_imports = array (); // alias => class name or directory
 10     private static $_includePaths; // list of include paths
 11     private static $_app;
 12     private static $_logger;
 13     public static function createWebApplication($config = null) {
 14         return self::createApplication ( 'CWebApplication', $config );
 15     }
 16     public static function createApplication($class, $config = null) {
 17         return new $class ( $config );
 18     }
 19     public static function app() {
 20         return self::$_app;
 21     }
 22     //别名路径
 23     public static function getPathOfAlias($alias) {
 24         if (isset ( self::$_aliases [$alias] ))
 25             return self::$_aliases [$alias];
 26         elseif (($pos = strpos ( $alias, '.' )) !== false) {
 27             $rootAlias = substr ( $alias, 0, $pos );
 28             if (isset ( self::$_aliases [$rootAlias] ))
 29                 return self::$_aliases [$alias] = rtrim ( self::$_aliases [$rootAlias] . DIRECTORY_SEPARATOR . str_replace ( '.', DIRECTORY_SEPARATOR, substr ( $alias, $pos + 1 ) ), '*' . DIRECTORY_SEPARATOR );
 30         }
 31         return false;
 32     }
 33     public static function setPathOfAlias($alias, $path) {
 34         if (empty ( $path ))
 35             unset ( self::$_aliases [$alias] );
 36         else
 37             self::$_aliases [$alias] = rtrim ( $path, '\/' );
 38     }
 39     public static function setApplication($app) {
 40         if (self::$_app === null || $app === null)
 41             self::$_app = $app;
 42     }
 43     public static function import($alias, $forceInclude = false) {
 44         if (isset ( self::$_imports [$alias] )) // previously imported
 45             return self::$_imports [$alias];
 46         
 47         if (class_exists ( $alias, false ) || interface_exists ( $alias, false ))
 48             return self::$_imports [$alias] = $alias;
 49         if (($pos = strrpos ( $alias, '.' )) === false)         // a simple class name
 50         {
 51             // try to autoload the class with an autoloader if $forceInclude is true
 52             if ($forceInclude && (Yii::autoload ( $alias, true ) || class_exists ( $alias, true )))
 53                 self::$_imports [$alias] = $alias;
 54             return $alias;
 55         }
 56         
 57         $className = ( string ) substr ( $alias, $pos + 1 );
 58         $isClass = $className !== '*';
 59         
 60         if ($isClass && (class_exists ( $className, false ) || interface_exists ( $className, false )))
 61             return self::$_imports [$alias] = $className;
 62         
 63         if (($path = self::getPathOfAlias ( $alias )) !== false) {
 64             if ($isClass) {
 65                 if ($forceInclude) {
 66                     if (is_file ( $path . '.php' ))
 67                         require ($path . '.php');
 68                     else
 69                         throw new CException ( Yii::t ( 'yii', 'Alias "{alias}" is invalid. Make sure it points to an existing PHP file and the file is readable.', array (
 70                                 '{alias}' => $alias 
 71                         ) ) );
 72                     self::$_imports [$alias] = $className;
 73                 } else
 74                     self::$classMap [$className] = $path . '.php';
 75                 return $className;
 76             } else             // a directory
 77             {
 78                 if (self::$_includePaths === null) {
 79                     self::$_includePaths = array_unique ( explode ( PATH_SEPARATOR, get_include_path () ) );
 80                     if (($pos = array_search ( '.', self::$_includePaths, true )) !== false)
 81                         unset ( self::$_includePaths [$pos] );
 82                 }
 83                 
 84                 array_unshift ( self::$_includePaths, $path );
 85                 
 86                 if (self::$enableIncludePath && set_include_path ( '.' . PATH_SEPARATOR . implode ( PATH_SEPARATOR, self::$_includePaths ) ) === false)
 87                     self::$enableIncludePath = false;
 88                 
 89                 return self::$_imports [$alias] = $path;
 90             }
 91         }
 92     }
 93     //创建组件实例
 94     public static function createComponent($config) {
 95         if (is_string ( $config )) {
 96             $type = $config;
 97             $config = array ();
 98         } elseif (isset ( $config ['class'] )) {
 99             $type = $config ['class'];
100             unset ( $config ['class'] );
101         }
102         if (! class_exists ( $type, false )) {
103             $type = Yii::import ( $type, true );
104         }
105         if (($n = func_num_args ()) > 1) {
106             $args = func_get_args ();
107             if ($n === 2)
108                 $object = new $type ( $args [1] );
109             elseif ($n === 3)
110                 $object = new $type ( $args [1], $args [2] );
111             elseif ($n === 4)
112                 $object = new $type ( $args [1], $args [2], $args [3] );
113             else {
114                 unset ( $args [0] );
115                 $class = new ReflectionClass ( $type );
116                 // Note: ReflectionClass::newInstanceArgs() is available for PHP 5.1.3+
117                 // $object=$class->newInstanceArgs($args);
118                 $object = call_user_func_array ( array (
119                         $class,
120                         'newInstance' 
121                 ), $args );
122             }
123         } else
124             $object = new $type ();
125         foreach ( $config as $key => $value )
126             $object->$key = $value;
127         
128         return $object;
129     }
130     //按需加载相应的php
131     public static function autoload($className) {
132         include self::$_coreClasses [$className];
133     }
134     private static $_coreClasses = array (
135             'CApplication' => '/base/CApplication.php',
136             'CModule' => '/base/CModule.php',
137             'CWebApplication' => '/base/CWebApplication.php',
138             'CUrlManager' => 'CUrlManager.php',
139             'CComponent' => '/base/CComponent.php'
140         ,    'CUrlRule' => 'CUrlRule.php',
141             'CController' => 'CController.php',
142             'CInlineAction' => '/actions/CInlineAction.php',
143             'CAction' => '/actions/CAction.php',
144             'CFilterChain' => '/filters/CFilterChain.php',
145             'CFilter' => '/filters/CFilter.php',
146             'CList' => '/collections/CList.php',
147             'CHttpRequest' => 'CHttpRequest.php',
148             'CDb' => 'CDb.php',
149             'CInlineFilter' => 'filters/CInlineFilter.php' 
150     );
151 }
152 
153 spl_autoload_register ( array (
154         'YiiBase',
155         'autoload' 
156 ) );

看似很多，其实就三个地方注意下就可以了

1.spl_autoload_register,用这个就可以实现传说中的按需加载相应的php了,坑爹啊。

2.createComponent($config)这个方法是yii组件调用的核心。在配置中注册的所有组件都是通过它获取组件类的实例的。比如配置：

 1 <?php
 2 return array (
 3         'basePath' => dirname ( __FILE__ ) . DIRECTORY_SEPARATOR . '..',
 4         
 5         'import' => array (
 6                 'application.util.*' 
 7         ),
 8         
 9         'components' => array (
10                 'db' => array (
11                         'class' => 'CDb',
12                         'driver' => 'mysql',
13                         'hostname' => 'localhost',
14                         'username' => 'root',
15                         'password' => '',
16                         'database' => 'youtube' 
17                 ),
18                 'urlManager' => array (
19                         'urlFormat' => 'path',
20                         'rules' => array (
21                                 'comment_reply/<a:d+>/<ci:d+>' => 'reply/load_comment_reply',
22                                 'b/<id:d+>' => array (
23                                         'video/broadcast',
24                                         'urlSuffix' => '.html' 
25                                 ),
26                                 'c/<list_start:d+>' => 'video/list_more_video',
27                                 'u/reg' => 'user/reg',
28                                 'v/upload' => 'video/upload_video',
29                                 'login' => 'user/to_login',
30                                 'show_chanel/<chanel_id:d+>' => 'show/chanel' ,
31                                 'show/<show_id:d+>' => 'show/show',
32                         ) 
33                 ) 
34         ) 
35 );
36 ?>

这个文件就返回了个map,里面components中的db,urlManager便是我注册的系统中的组件,里面的array便是组件的参数.

从源码中看到$type = $config ['class'];$object = new $type;就创建了注册的类实例了。

3.import($alias, $forceInclude = false)。作用：导入一个类或一个目录。导入一个类就像包含相应的类文件。主要区别是导入一个类比较轻巧，它仅在类文件首次引用时包含。这个也是yii的一个核心优化点。

这个在上面createComponent($config)中有用到，

if (!class_exists ( $type, false )) {
　　$type = Yii::import ( $type, true );
}

如果$type类没有定义，就去导入。有些组件，核心在yii中多次create调用，这样就保证了仅在类文件首次引用时导入。

下面分析index.php中Yii::createWebApplication ( $config )的调用过程。

这个调用是去了CWebApplication。

 1 <?php
 2 class CWebApplication extends CApplication {
 3     public $controllerNamespace;
 4     private $_controllerPath;
 5     private $_viewPath;
 6     private $_systemViewPath;
 7     private $_controller;
 8     public $controllerMap=array();
 9     public function processRequest() {//开始执行请求
10         //获取urlManager组件，解析请求，得到controller/action这种格式的string,
11         //并且将隐藏参数与请求的参数一一对应，匹配起来，写入$_REQUEST中
12         $route = $this->getUrlManager ()->parseUrl ($this->getRequest());
13         $this->runController ( $route );
14     }
15     public function getRequest() {//获取request组件
16         return $this->getComponent ( 'request' );
17     }
18     protected function registerCoreComponents() {//注册核心组件
19         parent::registerCoreComponents ();
20     }
21     //执行contronller
22     public function runController($route) {
23         if (($ca = $this->createController ( $route )) !== null) {
24             list ( $controller, $actionID ) = $ca;
25             $oldController = $this->_controller;
26             $this->_controller = $controller;
27             $controller->init ();//钩子,在执行action方法前调用，子类去实现
28             $controller->run ( $actionID );//开始转入controller类中action方法的执行
29             $this->_controller = $oldController;
30         }
31     }
32     //创建controller类实例,从controller/action这种格式的string中解析出$controller, $actionID 
33     public function createController($route, $owner = null) {
34         if ($owner === null)
35             $owner = $this;
36         if (($route = trim ( $route, '/' )) === '')
37             $route = $owner->defaultController;
38 
39         $route .= '/';
40         while ( ($pos = strpos ( $route, '/' )) !== false ) {
41             $id = substr ( $route, 0, $pos );
42             if (! preg_match ( '/^w+$/', $id ))
43                 return null;
44             $id = strtolower ( $id );
45             $route = ( string ) substr ( $route, $pos + 1 );
46             if (! isset ( $basePath ))             // first segment
47             {
48                 $basePath = $owner->getControllerPath ();
49                 $controllerID = '';
50             } else {
51                 $controllerID .= '/';
52             }
53             $className = ucfirst ( $id ) . 'Controller';
54             $classFile = $basePath . DIRECTORY_SEPARATOR . $className . '.php';
55 
56             if (is_file ( $classFile )) {
57                 if (! class_exists ( $className, false ))
58                     require ($classFile);
59                 if (class_exists ( $className, false ) && is_subclass_of ( $className, 'CController' )) {
60                     $id [0] = strtolower ( $id [0] );
61                     return array (
62                             new $className ( $controllerID . $id, $owner === $this ? null : $owner ),
63                             $this->parseActionParams ( $route )
64                     );
65                 }
66                 return null;
67             }
68             $controllerID .= $id;
69             $basePath .= DIRECTORY_SEPARATOR . $id;
70         }
71     }
72     protected function parseActionParams($pathInfo) {
73         if (($pos = strpos ( $pathInfo, '/' )) !== false) {
74             $manager = $this->getUrlManager ();//再次获取urlManager,在上面第一次调用中已经导入。
75             $manager->parsePathInfo ( ( string ) substr ( $pathInfo, $pos + 1 ) );
76             $actionID = substr ( $pathInfo, 0, $pos );
77             return $manager->caseSensitive ? $actionID : strtolower ( $actionID );
78         } else
79             return $pathInfo;
80     }
81     public function getControllerPath() {
82         if ($this->_controllerPath !== null)
83             return $this->_controllerPath;
84         else
85             return $this->_controllerPath = $this->getBasePath () . DIRECTORY_SEPARATOR . 'controllers';
86     }
87     //两个钩子,子类去实现
88     public function beforeControllerAction($controller, $action) {
89         return true;
90     }
91     public function afterControllerAction($controller, $action) {
92     }
93     protected function init() {
94         parent::init ();
95     }
96 }

没有构造方法，构造方法在父类CApplication里面。

 1 <?php
 2 abstract class CApplication extends CModule {
 3     private $_id;
 4     private $_basePath;
 5     abstract public function processRequest();
 6     public function __construct($config = null) {
 7         if (is_string ( $config ))
 8             $config = require ($config);
 9         Yii::setApplication ( $this );//保存整个app实例
10         if (isset ( $config ['basePath'] )) {
11             $this->setBasePath ( $config ['basePath'] );
12             unset ( $config ['basePath'] );
13         } else
14             $this->setBasePath ( 'protected' );
15         //设置别名,后面就可以用application表示basePath了
16         Yii::setPathOfAlias ( 'application', $this->getBasePath () );
17         //钩子，模块 预 初始化时执行，子类实现。不过这时，配置还没有写入框架
18         $this->preinit ();
19         $this->registerCoreComponents ();
20         //父类实现
21         $this->configure ( $config );
22         //加载静态应用组件
23         $this->preloadComponents ();
24         //这才开始初始化模块
25         $this->init ();
26     }
27     protected function registerCoreComponents() {
28         $components = array (
29                 'request' => array (
30                         'class' => 'CHttpRequest'
31                 ),
32                 'urlManager' => array (
33                         'class' => 'CUrlManager'
34                 )
35         );
36 
37         $this->setComponents ( $components );//父类实现
38     }
39     public function run() {
40         $this->processRequest ();
41     }
42     public function getId() {
43         if ($this->_id !== null)
44             return $this->_id;
45         else
46             return $this->_id = sprintf ( '%x', crc32 ( $this->getBasePath () . $this->name ) );
47     }
48     public function setId($id) {
49         $this->_id = $id;
50     }
51     public function getBasePath() {
52         return $this->_basePath;
53     }
54     public function setBasePath($path) {
55         if (($this->_basePath = realpath ( $path )) === false || ! is_dir ( $this->_basePath ))
56             return;
57     }
58     public function getDb() {
59         return $this->getComponent ( 'db' );//父类实现
60     }
61     public function getUrlManager() {
62         return $this->getComponent ( 'urlManager' );
63     }
64     public function getController() {
65         return null;
66     }
67     public function getBaseUrl($absolute = false) {
68         return $this->getRequest ()->getBaseUrl ( $absolute );
69     }
70 }

__construct里面注释写的很详细了，值得注意的是registerCoreComponents ()。前面说了那么多，那么Yii::createWebApplication ( $config )到底是做什么的。

其实最终目的对这个裁剪过的yii而言就是注册核心组件。就这么简单.

setComponents ( $components )在父类CModule里面.

 1 <?php
 2 abstract class CModule extends CComponent {
 3     public $preload = array ();
 4     public $behaviors = array ();
 5     private $_id;
 6     private $_parentModule;
 7     private $_basePath;
 8     private $_modulePath;
 9     private $_params;
10     private $_modules = array ();
11     private $_moduleConfig = array ();
12     private $_components = array ();
13     private $_componentConfig = array ();
14     //重写是为了方便直接用 application.组件 这种方式直接获取组件
15     public function __get($name) {
16         if ($this->hasComponent ( $name ))
17             return $this->getComponent ( $name );
18         else
19             return parent::__get ( $name );
20     }
21     public function __isset($name) {
22         if ($this->hasComponent ( $name ))
23             return $this->getComponent ( $name ) !== null;
24         else
25             return parent::__isset ( $name );
26     }
27     public function hasComponent($id) {
28         return isset ( $this->_components [$id] ) || isset ( $this->_componentConfig [$id] );
29     }
30     //
31     public function getComponent($id, $createIfNull = true) {
32         if (isset ( $this->_components [$id] ))
33             return $this->_components [$id];
34         else if (isset ( $this->_componentConfig [$id] ) && $createIfNull) {
35             $config = $this->_componentConfig [$id];
36             $component = Yii::createComponent ( $config );//YiiBase,返回组件实例
37             $component->init ();//钩子，调用子类重写的init方法
38             //将组件写入数组保存，并返回
39             return $this->_components [$id] = $component;
40         }
41     }
42     public function setComponent($id, $component, $merge = true) {
43         //组件写入数组保存
44         if (isset ( $this->_componentConfig [$id] ) && $merge) {
45             
46             $this->_componentConfig [$id] = self::mergeArray ( $this->_componentConfig [$id], $component );
47         } else {
48             
49             $this->_componentConfig [$id] = $component;
50         }
51     }
52     public static function mergeArray($a, $b) {
53         $args = func_get_args ();
54         $res = array_shift ( $args );
55         while ( ! empty ( $args ) ) {
56             $next = array_shift ( $args );
57             foreach ( $next as $k => $v ) {
58                 if (is_integer ( $k ))
59                     isset ( $res [$k] ) ? $res [] = $v : $res [$k] = $v;
60                 elseif (is_array ( $v ) && isset ( $res [$k] ) && is_array ( $res [$k] ))
61                     $res [$k] = self::mergeArray ( $res [$k], $v );
62                 else
63                     $res [$k] = $v;
64             }
65         }
66         return $res;
67     }
68     public function setComponents($components, $merge = true) {
69         foreach ( $components as $id => $component )
70             $this->setComponent ( $id, $component, $merge );
71     }
72     //子类CApplication调用，用来为模块指定配置
73     public function configure($config) {
74         if (is_array ( $config )) {
75             foreach ( $config as $key => $value )
76                 $this->$key = $value;
77         }
78     }
79     protected function preloadComponents() {
80         foreach ( $this->preload as $id )
81             $this->getComponent ( $id );
82     }
83     //又是两个钩子
84     protected function preinit() {
85     }
86     protected function init() {
87     }
88 }

看到所谓的注册组件就是写入数组保存，getComponent()的时候就是用前面讲到的YiiBase里面的createComponent($config)返回组件实例。就这么简单。

而CApplication里面的什么getDb()，getUrlManager()也是在调用getComponent()。

最后附上，裁剪的yii http://files.cnblogs.com/TheViper/framework.zip