YII 的源码分析(三)

前面已经看完了启动一个yii程序所要经过的流程，以及渲染一个页面是怎么完成的。今天要分析的是yii是如何处理用户请求的。也就是控制和动作部分。

还是以helloworld为例演示这一过程。我们在地址栏输入http://localhost/study/yii/demos/helloworld/index.php，页面就显示了hello world.

前面的分析都是用的默认值，但是如果url有参数的时候，yii又是怎么处理的呢？带着这个问题，我们具体来分析一下。

在CWebApplication中有这样一行代码:

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

这就是传说中的路由了，是不是有点小鸡冻呢？先看看getUrlManager是个神马。

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

这个又要通过找关系了.

    <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>

执行了return $this->_components[$id]; id就是传进去的urlManager,其实从这里也还看不出什么，直接找到urlManager这个类，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>

从上面的代码来看，如果我们不在url上传点东西，直接就return ''了。于是问题来了，参数要怎么传呢？

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

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

于是有办法了，让我们一起来使点坏吧。加上这样的一个参数helloworld/index.php?r=abc

发现报错了。说明abc这个控制器是不存在的，事实上也是不存在的，使点小坏坏而已，正所谓男人不坏，女人不爱。

改成helloworld/index.php?r=site就可以显示hello world了，这是什么鬼原理呢？原因很简单，因为定义了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，这个我没有意见，但是actionIndex又是神么鬼？在yii中，这称为动作。它捕获的是控制器后面的参数，如果我们输?r=site/index就是index,动作是用“/"进行分隔的，为了验正一下我说的不是骗女孩子的鬼话，我在site控制器里加一个动作给你看一下：

<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>

访问?r=site/view的时候，是不是看到输出'Hello View'了呢？肯定是的，虽然我读的书少，但是你骗不了我的，有图有真相：

我一点儿也不喜欢用site这个名字，test才是我的最爱，于是我又建了一个test控制器来尝试一下。

眼尖的一定看到怎么写了一个actions，这是什么鬼？我也是刚试了才知道，它其实是另一种表示方式。

我记得在blog那个例子中有用过，用来显示验证码：

    <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>

我把它理解为集中声明第三方业务的动作集合，因为本控制器内的动作，我觉得还是action+ID 的方式直接。

什么鬼？你说我用的是index.php/site/captcha 而不是index.php?r=site/captcha .这又得从配置文件说起。

        '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:>