YII 的源码分析(二)

上一篇简单分析了一下yii的流程，从创建一个应用，到屏幕上输出结果。这一次我来一个稍复杂一点的,重点在输出上，不再是简单的一行"hello world"，而是要经过view（视图）层的处理。

依然是demos目录，这次我们选择hangman，一个简单的猜字游戏。老规则，还是从入口处开始看。

index.php:

<span>php

</span><span>//</span><span> change the following paths if necessary</span>
<span>$yii</span>=<span>dirname</span>(<span>__FILE__</span>).'/../../framework/yii.php'<span>;
</span><span>$config</span>=<span>dirname</span>(<span>__FILE__</span>).'/protected/config/main.php'<span>;

</span><span>//</span><span> remove the following line when in production mode
// defined('YII_DEBUG') or define('YII_DEBUG',true);</span>

<span>require_once</span>(<span>$yii</span><span>);
Yii</span>::createWebApplication(<span>$config</span>)->run();

和helloworld应用相比，这次多了main.php,打开main看下源码：

<span>php

</span><span>return</span> <span>array</span><span>(
    </span>'name'=>'Hangman Game',
    'defaultController'=>'game',
    'components'=><span>array</span><span>(
        </span>'urlManager'=><span>array</span><span>(
            </span>'urlFormat'=>'path',
            'rules'=><span>array</span><span>(
                </span>'game/guess/<g:>'=>'game/guess',<span>
            )</span>,<span>
        )</span>,<span>
    )</span>,<span>
);</span></g:>

在我们以后的实际项目中，也是经常要用到配置文件的，所以我觉得有必要了解一下yii的配置文件--main.php

'name'=>'这里通常是定义网站的标题'，也就是我们打开index.php时，在网页上显示的标题。

'defaultController'=>'这里是默认的控制器',也就是我们的index.php后面没有指定控制器时系统采用的控制器，如果我们这里没有指出来，默认就是site

'components'=>'这里是组件的参数，用多维数组进行配置。' 具体的参数可以查看yii手册。

Yii::createWebApplication($config)->run(); 上一次我们已经详细分析过它了，这里再简单的走一遍：

CWebApplication.php -> CApplication.php -> __construct($config) :

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

        </span><span>$this</span>-><span>initSystemHandlers();
        </span><span>$this</span>-><span>registerCoreComponents();

        </span><span>$this</span>->configure(<span>$config</span><span>);
        </span><span>$this</span>->attachBehaviors(<span>$this</span>-><span>behaviors);
        </span><span>$this</span>-><span>preloadComponents();

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

上次我们没有配置过程，所以$this->configure($config)什么也没有做，但是这次有配置参数，所以我们进去看看yii做了哪些操作：

CApplication自己没有实现configure方法，是继承于CModule.php的：

    <span>public</span> <span>function</span> configure(<span>$config</span><span>)
    {
        </span><span>if</span>(<span>is_array</span>(<span>$config</span><span>))
        {
            </span><span>foreach</span>(<span>$config</span> <span>as</span> <span>$key</span>=><span>$value</span><span>)
                </span><span>$this</span>-><span>$key</span>=<span>$value</span><span>;
        }
    }</span>

代码非常简单，就是把配置参数的键做为类的属性名，value做为类的属性值进行了扩展。完成这一过程就运行CApplication 上的run方法了。

    <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>

我们前面说过，这里只要关注 $this->processRequest(); 就可以了。运行的结果就是执行$this->runController('');  

    <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>

由于url是index.php，后面没有任何参数，所以都是走的默认控制器，也就是我们在main.php中设定的game. 所以$controller 就等于 controllers/gameController.php, 通过上次的源码分析我们可以知道，在gameController.php中没有init方法时，都是走的父类中定义的默认方法(实际上是一个空方法)，

$controller->run($actionID<span>); == gameController</span>->run(''); gameController上没有实现run方法，于是又是去父类中找run

从class GameController extends CController 可以看出，父类是CController , 找到相应的run方法：

<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>

前面已经分析过了，没有指定时，都是默认参数。那么此时的$actionID为空，actionID就是gameController中定义的默认动作：public $defaultAction='play'; 

runActionWithFilters --->  runAction --> $action->runWithParams<br>这里的$action 需要从CAction -> CInlineAction中去找<br>

<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>

走了这么多过程，和hello world的流程是差不多的。据上次的分析可以知道，这里执行了

$controller->$methodName<span>(); 也就是GameController->actionPlay()<br>到此，我们本节的重点才真正开始：<br></span>

    <span>public</span> <span>function</span><span> actionPlay()
    {
        </span><span>static</span> <span>$levels</span>=<span>array</span><span>(
            </span>'10'=>'Easy game; you are allowed 10 misses.',
            '5'=>'Medium game; you are allowed 5 misses.',
            '3'=>'Hard game; you are allowed 3 misses.',<span>
        );

        </span><span>//</span><span> if a difficulty level is correctly chosen</span>
        <span>if</span>(<span>isset</span>(<span>$_POST</span>['level']) && <span>isset</span>(<span>$levels</span>[<span>$_POST</span>['level'<span>]]))
        {
            </span><span>$this</span>->word=<span>$this</span>-><span>generateWord();
            </span><span>$this</span>->guessWord=<span>str_repeat</span>('_',<span>strlen</span>(<span>$this</span>-><span>word));
            </span><span>$this</span>->level=<span>$_POST</span>['level'<span>];
            </span><span>$this</span>->misses=0<span>;
            </span><span>$this</span>->setPageState('guessed',<span>null</span><span>);
            </span><span>//</span><span> show the guess page</span>
            <span>$this</span>->render('guess'<span>);
        }
        </span><span>else</span><span>
        {
            </span><span>$params</span>=<span>array</span><span>(
                </span>'levels'=><span>$levels</span>,
                <span>//</span><span> if this is a POST request, it means the level is not chosen</span>
                'error'=>Yii::app()->request->isPostRequest,<span>
            );
            </span><span>//</span><span> show the difficulty level page</span>
            <span>$this</span>->render('play',<span>$params</span><span>);
        }
    }</span>

<span>显然走的是else的逻辑，重点请看</span> $this->render('play',$params); 这个render方法这么面熟，很多框架中都有类似的方法，比如discuz,smarty,CI 等等. 纵观yii框架，rnder 在它整个MVC模式中，是V得以实现的重要骨干。所以有必要把它翻个底朝天。<br>在CController.php中有这个方法：

    <span>public</span> <span>function</span> render(<span>$view</span>,<span>$data</span>=<span>null</span>,<span>$return</span>=<span>false</span><span>)
    {
        </span><span>if</span>(<span>$this</span>->beforeRender(<span>$view</span><span>))
        {
            </span><span>$output</span>=<span>$this</span>->renderPartial(<span>$view</span>,<span>$data</span>,<span>true</span><span>);
            </span><span>if</span>((<span>$layoutFile</span>=<span>$this</span>->getLayoutFile(<span>$this</span>->layout))!==<span>false</span><span>)
                </span><span>$output</span>=<span>$this</span>->renderFile(<span>$layoutFile</span>,<span>array</span>('content'=><span>$output</span>),<span>true</span><span>);

            </span><span>$this</span>->afterRender(<span>$view</span>,<span>$output</span><span>);

            </span><span>$output</span>=<span>$this</span>->processOutput(<span>$output</span><span>);

            </span><span>if</span>(<span>$return</span><span>)
                </span><span>return</span> <span>$output</span><span>;
            </span><span>else</span>
                <span>echo</span> <span>$output</span><span>;
        }
    }</span>

当我们echo $output=$this->renderPartial($view,$data,true);的时候，就发现，此时的$output已经就拿到我们最终的结果了。它对应的文件是views/game/play.php

也就是我们在index.php上最终看到的内容了。由于本次渲染比较简单，所以程序经过的流程也较少，但是从源码中可以看到，里边进行了许多的处理，比如主题什么的。本次就先分析到这。晚安！

<br>

以上就介绍了YII 的源码分析(二)，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。