YII 的源碼分析(三)

前面已經看完了啟動一個yii程式所要經過的流程，以及渲染一個頁面是怎麼完成的。今天要分析的是yii是如何處理使用者請求的。也就是控制和動作部分。

還是以helloworld為例示範此過程。我們在網址列輸入http://localhost/study/yii/demos/helloworld/index.php，頁面顯示了hello world.

前面的分析都是用的預設值，但是如果url有參數的時候，yii又是怎麼處理的呢？帶著這個問題，我們具體來分析一下。

在CWebApplication中有這樣一行程式碼:

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

這就是傳說中的路由了，是不是有點小雞凍呢？先看看getUrlManager是個神馬。

    <span>public</span> <span>function</span><span> getUrlManager()
    {
        </span><span>return</span> <span>$this</span>->getComponent('urlManager'<span>);
    }</span>

這個又要透過找關係了.

    <span>public</span> <span>function</span> getComponent(<span>$id</span>,<span>$createIfNull</span>=<span>true</span><span>)
    {
        </span><span>if</span>(<span>isset</span>(<span>$this</span>->_components[<span>$id</span><span>]))
            </span><span>return</span> <span>$this</span>->_components[<span>$id</span><span>];
        </span><span>elseif</span>(<span>isset</span>(<span>$this</span>->_componentConfig[<span>$id</span>]) && <span>$createIfNull</span><span>)
        {
            </span><span>$config</span>=<span>$this</span>->_componentConfig[<span>$id</span><span>];
            </span><span>if</span>(!<span>isset</span>(<span>$config</span>['enabled']) || <span>$config</span>['enabled'<span>])
            {
                Yii</span>::trace("Loading \"<span>$id</span>\" application component",'system.CModule'<span>);
                </span><span>unset</span>(<span>$config</span>['enabled'<span>]);
                </span><span>$component</span>=Yii::createComponent(<span>$config</span><span>);
                </span><span>$component</span>-><span>init();
                </span><span>return</span> <span>$this</span>->_components[<span>$id</span>]=<span>$component</span><span>;
            }
        }
    }</span>

執行了return $this->_components[$id]; id就是傳進去的urlManager,其實從這裡也還看不出什麼，直接找到urlManager這個類，看parseUrl：

    <span>public</span> <span>function</span> parseUrl(<span>$request</span><span>)
    {
        </span><span>if</span>(<span>$this</span>->getUrlFormat()===self::<span>PATH_FORMAT)
        {
            </span><span>$rawPathInfo</span>=<span>$request</span>-><span>getPathInfo();
            </span><span>$pathInfo</span>=<span>$this</span>->removeUrlSuffix(<span>$rawPathInfo</span>,<span>$this</span>-><span>urlSuffix);
            </span><span>foreach</span>(<span>$this</span>->_rules <span>as</span> <span>$i</span>=><span>$rule</span><span>)
            {
                </span><span>if</span>(<span>is_array</span>(<span>$rule</span><span>))
                    </span><span>$this</span>->_rules[<span>$i</span>]=<span>$rule</span>=Yii::createComponent(<span>$rule</span><span>);
                </span><span>if</span>((<span>$r</span>=<span>$rule</span>->parseUrl(<span>$this</span>,<span>$request</span>,<span>$pathInfo</span>,<span>$rawPathInfo</span>))!==<span>false</span><span>)
                    </span><span>return</span> <span>isset</span>(<span>$_GET</span>[<span>$this</span>->routeVar]) ? <span>$_GET</span>[<span>$this</span>->routeVar] : <span>$r</span><span>;
            }
            </span><span>if</span>(<span>$this</span>-><span>useStrictParsing)
                </span><span>throw</span> <span>new</span> CHttpException(404,Yii::t('yii','Unable to resolve the request "{route}".',
                    <span>array</span>('{route}'=><span>$pathInfo</span><span>)));
            </span><span>else</span>
                <span>return</span> <span>$pathInfo</span><span>;
        }
        </span><span>elseif</span>(<span>isset</span>(<span>$_GET</span>[<span>$this</span>-><span>routeVar]))
            </span><span>return</span> <span>$_GET</span>[<span>$this</span>-><span>routeVar];
        </span><span>elseif</span>(<span>isset</span>(<span>$_POST</span>[<span>$this</span>-><span>routeVar]))
            </span><span>return</span> <span>$_POST</span>[<span>$this</span>-><span>routeVar];
        </span><span>else</span>
            <span>return</span> ''<span>;
    }</span>

從上面的程式碼來看，如果我們不在url上傳點東西，直接就return ''了。於是問題來了，參數要怎麼傳呢？

isset($_GET[$this-><span>routeVar]) <br></span>

<span>public</span> <span>$routeVar</span>='r';

於是有辦法了，讓我們一起來使點壞吧。加上這樣的一個參數helloworld/index.php?r=abc

發現報錯了。說明abc這個控制器是不存在的，事實上也是不存在的，使點小壞壞而已，正所謂男人不壞，女人不愛。

改成helloworld/index.php?r=site就可以顯示hello world了，這是什麼鬼原理呢？原因很簡單，因為定義了site控制器嘛。

<span>class</span> SiteController <span>extends</span><span> CController
{
    </span><span>/*</span><span>*
     * Index action is the default action in a controller.
     </span><span>*/</span>
    <span>public</span> <span>function</span><span> actionIndex()
    {
        </span><span>echo</span> 'Hello World'<span>;
    }</span><span>
}</span>

好吧，這個我沒有意見，但是actionIndex又是神麼鬼？在yii中，這稱為動作。它捕獲的是控制器後面的參數，如果我們輸?r=site/index就是index,動作是用“/"進行分隔的，為了驗正一下我說的不是騙女孩子的鬼話，我在site控制器裡加一個動作給你看：

<span>class</span> SiteController <span>extends</span><span> CController
{
    </span><span>/*</span><span>*
     * Index action is the default action in a controller.
     </span><span>*/</span>
    <span>public</span> <span>function</span><span> actionIndex()
    {
        </span><span>echo</span> 'Hello World'<span>;
    }

    </span><span>public</span> <span>function</span><span> actionView()
    {
        </span><span>echo</span> 'Hello View'<span>;
    }

}</span>

訪問?r=site/view的時候，是不是看到輸出'Hello View'了呢？肯定是的，雖然我讀的書少，但是你騙不了我的，有圖有真相：

我一點也不喜歡用site這個名字，test才是我的最愛，於是我又建了一個test控制器來嘗試。

眼尖的一定看到怎麼寫了一個actions，這是什麼鬼？我也是剛試了才知道，它其實是另一種表示方式。

我記得在blog那個例子中有用過，用來顯示驗證碼：

    <span>/*</span><span>*
     * Declares class-based actions.
     </span><span>*/</span>
    <span>public</span> <span>function</span><span> actions()
    {
        </span><span>return</span> <span>array</span><span>(
            </span><span>//</span><span> captcha action renders the CAPTCHA image displayed on the contact page</span>
            'captcha'=><span>array</span><span>(
                </span>'class'=>'CCaptchaAction',
                'backColor'=>0xFFFFFF,<span>
            )</span>,
            <span>//</span><span> page action renders "static" pages stored under 'protected/views/site/pages'
            // They can be accessed via: index.php?r=site/page&view=FileName</span>
            'page'=><span>array</span><span>(
                </span>'class'=>'CViewAction',<span>
            )</span>,<span>
        );
    }</span>

我把它理解為集中聲明第三方業務的動作集合，因為本控制器內的動作，我覺得還是action+ID 的方式直接。

什麼鬼？你說我用的是index.php/site/captcha 而不是index.php?r=site/captcha .這又得從設定檔說起。

        'urlManager'=><span>array</span><span>(
            </span>'urlFormat'=>'path',
            'rules'=><span>array</span><span>(
                </span>'post/<id:>/<.><.><controller:><action:><controller><action><span></span><span></span></action></controller></action:></controller:></.></.></id:>