YII 的源碼分析(-)

WBOY
發布: 2016-08-08 09:33:00
原創
1211 人瀏覽過

做為源碼分析的首秀,我就挑了yii(讀作歪依依而不是歪愛愛);它的讚美之詞我就不多說了,直接入正題。先準備材料,建議直從官網下載yii的源碼包(1.1.15)最新版本。

在demos裡邊有一個最簡單的應用—helloworld.就是用yii框架輸出一句話:”hello world”;

我就從它下手,分析框架執行一個最小流程要經過哪些元件,淺析它的運作過程。

首先從單一入口文件開始閱讀。 (源碼一般都是從呼叫處開始分析)

Index.php->

// include Yii bootstrap file

//引入啟動檔案

require_once(dirname(__FILE__).'/../../framework/yii.php');

 

yii.php ->

//YiiBase is a helper class serving common framework functionalities.

//YiiBase是一個助手類,它服務於整個框架。 這裡定義了許多重要的常數

require(dirname(__FILE__).'/YiiBase.php');

//註冊自動載入類別

spl_autoload_register(array('YiiBase','autoload'));

//導入介面類別

require(YII_PATH.'/base/interfaces.php');

//啟動應用

Yii::createWebApplication()->run();

程式碼到這裡似乎就終結了,頁面的內容也程現出來,可是框架到底做了些什麼,我們卻一無所知。所以我們需要把這一步分解,把裡邊的細節露出來。

Yii::createWebApplication()->run() 總共可以分成三個部分

  1. Yii
  2. createWebApplication
  3. run

Yii 這個東西是什麼?

從yii.php 可以找到這樣一行程式碼class Yii extends YiiBase

說明它就是YiiBase的繼承類,而且作者的擴展是留空的,所以Yii就是YiiBase的一個引用而已。所以createWebApplication這個靜態方法也得去YiiBase找了。

在YiiBase.php中,很容易就發現了這個方法:

public static function createWebApplication($config=null)

         {

                   return self::createApplication('CWebApplication',$config);

         }

它又把任務傳遞給了createApplication:

         public static function createApplication($class,$config=null)

         {

                   return new $class($config);

         }

結合起來看,createWebApplication () 就是return new CWebApplication($config);

這個CWebApplication類別又在哪裡?它又是怎麼引入的呢?

帶著一連串的問題,我又回到了YiiBase.php

那裡邊定義了一個很長的數組,你可以找到:

'CWebApplication' => '/web/CWebApplication.php',這就是自動載入類別中的一員

關於它是如何實現自動加載的,可以查看spl_autoload_register的相關文檔,此處就節外生枝了.

 

我們繼續往CWebApplication這個裡邊深挖。開啟/web/CWebApplication.php這個檔案。

前面提到return new CWebApplication($config);根據我的經驗,用了new ,通常會有一個構造函數的,但我卻沒有找到它的構造函數,肯定是在它的父類中,於是我往上找,class CWebApplication extends CApplication 果然被我發現了,這就跟挖泥鰍一樣的,得順著線索一點點的找,要有耐心。

 

CApplication 中果然有建構函數,程式碼如下:

<spanmicrosoft yahei font-size:><span>public</span> <span>function</span> __construct(<span>$config</span>=<span>null</span><span>)

         {

                   Yii</span>::setApplication(<span>$this</span><span>);

 

                   </span><span>//</span><span> set basePath at early as possible to avoid trouble</span>

                   <span>if</span>(<span>is_string</span>(<span>$config</span><span>))

                            </span><span>$config</span>=<span>require</span>(<span>$config</span><span>);

                   </span><span>if</span>(<span>isset</span>(<span>$config</span>['basePath'<span>]))

                   {

                            </span><span>$this</span>->setBasePath(<span>$config</span>['basePath'<span>]);

                            </span><span>unset</span>(<span>$config</span>['basePath'<span>]);

                   }

                   </span><span>else</span>

                            <span>$this</span>->setBasePath('protected'<span>);

                   Yii</span>::setPathOfAlias('application',<span>$this</span>-><span>getBasePath());

                   Yii</span>::setPathOfAlias('webroot',<span>dirname</span>(<span>$_SERVER</span>['SCRIPT_FILENAME'<span>]));

                   </span><span>if</span>(<span>isset</span>(<span>$config</span>['extensionPath'<span>]))

                   {

                            </span><span>$this</span>->setExtensionPath(<span>$config</span>['extensionPath'<span>]);

                            </span><span>unset</span>(<span>$config</span>['extensionPath'<span>]);

                   }

                   </span><span>else</span><span>

                            Yii</span>::setPathOfAlias('ext',<span>$this</span>->getBasePath().DIRECTORY_SEPARATOR.'extensions'<span>);

                   </span><span>if</span>(<span>isset</span>(<span>$config</span>['aliases'<span>]))

                   {

                            </span><span>$this</span>->setAliases(<span>$config</span>['aliases'<span>]);

                            </span><span>unset</span>(<span>$config</span>['aliases'<span>]);

                   }</span></spanmicrosoft>
登入後複製

 

   //以上都可以看成是初始化,設定類別的引用,別名,路徑什麼的。

                   $this->preinit();//暫時未發現有什麼用,估計是留給後面擴充的

 

                   $this->initSystemHandlers();//設定錯誤處理

                   $this->registerCoreComponents();//註冊核心元件

 

                   $this->configure($config);        //化

                   $this->attachBehaviors($this->behaviors);

                   $this->preloadComponents();

 

                   $this->init();

         }

$this下面的某些方法,在當前類別是找不到的,因為它們可能是來自父類,最簡單的方法就是ctrl+f搜尋一下,沒有就去類的聲明處查看:

abstract class CApplication extends CModule  

顯然要進入CModule,如果此時還找不到想要方法,那麼繼續上一過程:

abstract class CModule extends CComponent

直到class CComponent

說明這就是當前這些傢伙的老巢了。從程式碼的中註解也可以看到:

CComponent is the base class for all components

說明我的想法是正確的,沒錯,它就是基底類別。

透過程式碼,我們可以發現,我們目前的應用,因為很多參數是空,所以很多邏輯都是直接跳過的。

看到這,$this的內容也大致明了啦。我們再回頭看看

return new CWebApplication($config)->run();

透過前面的層層分析,此時的run方法也很好找了。就在CApplication 裡邊:

<spanmicrosoft yahei font-size:><span>public</span> <span>function</span><span> run()

         {

                   </span><span>if</span>(<span>$this</span>->hasEventHandler('onBeginRequest'<span>)){

                            </span><span>$this</span>->onBeginRequest(<span>new</span> CEvent(<span>$this</span><span>));

                   }

 

                   </span><span>register_shutdown_function</span>(<span>array</span>(<span>$this</span>,'end'),0,<span>false</span><span>);

                   </span><span>$this</span>-><span>processRequest();  

                   </span><span>if</span>(<span>$this</span>->hasEventHandler('onEndRequest'<span>)){

                            </span><span>$this</span>->onEndRequest(<span>new</span> CEvent(<span>$this</span><span>));

                   }

 

         }</span></spanmicrosoft>
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重点放在:$this->processRequest(); 因为前面和后面部分都是注册事件相关的,当前条件下执行不到。

<spanmicrosoft yahei font-size:><span>abstract</span> <span>public</span> <span>function</span> processRequest(); 这个方法在当前类中是抽象的,所以肯定在它的子类中实现了。回去找CWebApplication:

         <span>public</span> <span>function</span><span> processRequest()

         {

                   </span><span>if</span>(<span>is_array</span>(<span>$this</span>->catchAllRequest) && <span>isset</span>(<span>$this</span>->catchAllRequest[0<span>]))

                   {

                            </span><span>$route</span>=<span>$this</span>->catchAllRequest[0<span>];

                            </span><span>foreach</span>(<span>array_splice</span>(<span>$this</span>->catchAllRequest,1) <span>as</span> <span>$name</span>=><span>$value</span><span>)

                                     </span><span>$_GET</span>[<span>$name</span>]=<span>$value</span><span>;

                   }

                   </span><span>else</span>

                            <span>$route</span>=<span>$this</span>->getUrlManager()->parseUrl(<span>$this</span>-><span>getRequest());

 

                   </span><span>$this</span>->runController(<span>$route</span><span>);

         }</span></spanmicrosoft>
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注意重点在$this->runController($route);

 

<spanmicrosoft yahei font-size:><span>public</span> <span>function</span> runController(<span>$route</span><span>)

         {

                   </span><span>if</span>((<span>$ca</span>=<span>$this</span>->createController(<span>$route</span>))!==<span>null</span><span>)

                   {

                            </span><span>list</span>(<span>$controller</span>,<span>$actionID</span>)=<span>$ca</span><span>;

 

                            </span><span>$oldController</span>=<span>$this</span>-><span>_controller;

                            </span><span>$this</span>->_controller=<span>$controller</span><span>;

                            </span><span>$controller</span>-><span>init();

                            </span><span>$controller</span>->run(<span>$actionID</span><span>);

                            </span><span>$this</span>->_controller=<span>$oldController</span><span>;

                   }

                   </span><span>else</span>

                            <span>throw</span> <span>new</span> CHttpException(404,Yii::t('yii','Unable to resolve the request "{route}".',

                                     <span>array</span>('{route}'=><span>$route</span>===''?<span>$this</span>->defaultController:<span>$route</span><span>)));

         }</span></spanmicrosoft>
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我们要注意的代码只有两行:

$controller->init();

$controller->run($actionID);

这里的$controller可以能过查看createController得知,就是默认的控制器Sitecontroller.php

而Action则是index,你问我是怎么看出来的?哈哈,我在猜不出来的地方echo或var_dump一下不就可以了吗?这么简单的逻辑,还轮不到xdebug 这样的神器出场。

显然,init什么也没有做,看看run做了什么

Sitecontroller中没有run方法,又要去它的父类中查找。

class SiteController extends CController

 

在CController中有这个方法:

<spanmicrosoft yahei font-size:><span>public</span> <span>function</span> run(<span>$actionID</span><span>)

         {

                   </span><span>if</span>((<span>$action</span>=<span>$this</span>->createAction(<span>$actionID</span>))!==<span>null</span><span>)

                   {

                            </span><span>if</span>((<span>$parent</span>=<span>$this</span>->getModule())===<span>null</span><span>){

                                     </span><span>$parent</span>=Yii::<span>app();

                            }

 

                            </span><span>if</span>(<span>$parent</span>->beforeControllerAction(<span>$this</span>,<span>$action</span><span>))

                            {

                                     </span><span>$this</span>->runActionWithFilters(<span>$action</span>,<span>$this</span>-><span>filters());

                                     </span><span>$parent</span>->afterControllerAction(<span>$this</span>,<span>$action</span><span>);

                            }

                   }

                   </span><span>else</span>

                            <span>$this</span>->missingAction(<span>$actionID</span><span>);

         }

 </span></spanmicrosoft>
登入後複製

 

能过查看$this->createAction($actionID),得到return new CInlineAction($this,$actionID);

我们呆会再看这个CInlineAction,先看$this->runActionWithFilters($action,$this->filters());

<spanmicrosoft yahei font-size:><span>public</span> <span>function</span> runActionWithFilters(<span>$action</span>,<span>$filters</span><span>)

         {

                   </span><span>if</span>(<span>empty</span>(<span>$filters</span><span>)){

                            </span><span>$this</span>->runAction(<span>$action</span><span>);

                   }

                   </span><span>else</span><span>

                   {

                            </span><span>$priorAction</span>=<span>$this</span>-><span>_action;

                            </span><span>$this</span>->_action=<span>$action</span><span>;

                            CFilterChain</span>::create(<span>$this</span>,<span>$action</span>,<span>$filters</span>)-><span>run();

                            </span><span>$this</span>->_action=<span>$priorAction</span><span>;

                   }

         }</span></spanmicrosoft>
登入後複製

 

显然$filters是空的,所以执行第一个表达式$this->runAction($action);

 

<spanmicrosoft yahei font-size:><span>public</span> <span>function</span> runAction(<span>$action</span><span>)

         {

 

                   </span><span>$priorAction</span>=<span>$this</span>-><span>_action;

                   </span><span>$this</span>->_action=<span>$action</span><span>;

                   </span><span>if</span>(<span>$this</span>->beforeAction(<span>$action</span><span>))

                   {

 

                            </span><span>if</span>(<span>$action</span>->runWithParams(<span>$this</span>->getActionParams())===<span>false</span><span>){

                                     </span><span>$this</span>->invalidActionParams(<span>$action</span><span>);

                            }

 

                            </span><span>else</span><span>{

                                     </span><span>$this</span>->afterAction(<span>$action</span><span>);

 

                            }

 

                   }

                   </span><span>$this</span>->_action=<span>$priorAction</span><span>;

         }</span></spanmicrosoft>
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这段代码的重点是 $action->runWithParams($this->getActionParams())这一句;

这里的$action就是$this->createAction($actionID)返回的结果,而它的结果就是

return new CInlineAction($this,$actionID);

 

CInlineAction.php

是时候查看CInlineAction了;

 

        

<spanmicrosoft yahei font-size:> <span>public</span> <span>function</span> runWithParams(<span>$params</span><span>)

         {

                   </span><span>$methodName</span>='action'.<span>$this</span>-><span>getId();

                   </span><span>$controller</span>=<span>$this</span>-><span>getController();

                   </span><span>$method</span>=<span>new</span> ReflectionMethod(<span>$controller</span>, <span>$methodName</span><span>);

                   </span><span>if</span>(<span>$method</span>->getNumberOfParameters()>0<span>)

                            </span><span>return</span> <span>$this</span>->runWithParamsInternal(<span>$controller</span>, <span>$method</span>, <span>$params</span><span>);

                   </span><span>else</span>

                            <span>return</span> <span>$controller</span>-><span>$methodName</span><span>();

         }</span></spanmicrosoft>
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哇哦,好高级,居然还用了反射,不过我喜欢!

不过呢,打印$method发现:

object(ReflectionMethod)#6 (2) {

 

["name"]=>

 

string(11) "actionIndex"

 

["class"]=>

 

string(14) "SiteController"

 

}

没有参数,所以此处代码相当于是执行了SiteController->actionIndex();

在class SiteController extends CController中可以看到actionIndex 的定义

        

<spanmicrosoft yahei font-size:> <span>public</span> <span>function</span><span> actionIndex()

         {

                   </span><span>echo</span> 'Hello World'<span>;

         }</span></spanmicrosoft>
登入後複製

 

于是就看到屏幕上那一句Hello World ,整个程序也就跑完了。也许有人要问了,为什么输出一句话还这么复杂,不是脱了裤子打屁吗? (请允许我的粗俗);

如果是这么简单的需求,当然不可能这么干。举这个例子,只是说明yii的基础流程,为下面的复杂应用做一个过渡。

Yii作为一个优秀的oop框架,这个例子只是介绍了它的继承,接口,mvc中的vc特性,关于数据模型,我将在后面的分析中陆续给出。最终的目标,是利用yii框架简化我们的开发过程。

好了,今天的分析就在到了,如果有什么不妥的,请留言,如果觉得有帮助,请顺手点个推荐!

以上就介绍了YII 的源码分析(-),包括了方面的内容,希望对PHP教程有兴趣的朋友有所帮助。

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