分发器的具体实现
Zend Framework的分发器Zend_Controller_Dispatcher设计主要有，如下类和接口组成：
├── Dispatcher│ ├── Abstract.php│ ├── Exception.php│ ├── Interface.php│ └── Standard.php
定义了分发器提供的基本和标准功能。
interface Zend_Controller_Dispatcher_Interface{ public function formatControllerName($unformatted); public function formatModuleName($unformatted); public function formatActionName($unformatted); public function isDispatchable(Zend_Controller_Request_Abstract $request); public function setParam($name, $value); public function setParams(array $params); public function getParam($name); public function getParams(); public function clearParams($name = null); public function setResponse(Zend_Controller_Response_Abstract $response = null); public function getResponse(); public function addControllerDirectory($path, $args = null); public function setControllerDirectory($path); public function getControllerDirectory(); public function dispatch(Zend_Controller_Request_Abstract $request, Zend_Controller_Response_Abstract $response); public function isValidModule($module); public function getDefaultModule(); public function getDefaultControllerName(); public function getDefaultAction();}实现了Zend_Controller_Dispatcher_Interface接口，提供了分发器提供的基本和标准功能的抽象父类。
<?php/** Zend_Controller_Dispatcher_Interface */require_once 'Zend/Controller/Dispatcher/Interface.php';abstract class Zend_Controller_Dispatcher_Abstract implements Zend_Controller_Dispatcher_Interface{ protected $_defaultAction = 'index'; protected $_defaultController = 'index'; protected $_defaultModule = 'default'; protected $_frontController; protected $_invokeParams = array(); protected $_pathDelimiter = '_'; protected $_response = null; protected $_wordDelimiter = array('-', '.'); public function __construct(array $params = array()) { $this->setParams($params); } public function formatControllerName($unformatted) { return ucfirst($this->_formatName($unformatted)) . 'Controller'; } public function formatActionName($unformatted) { $formatted = $this->_formatName($unformatted, true); return strtolower(substr($formatted, 0, 1)) . substr($formatted, 1) . 'Action'; } public function _verifyDelimiter($spec) { if (is_string($spec)) { return (array) $spec; } elseif (is_array($spec)) { $allStrings = true; foreach ($spec as $delim) { if (!is_string($delim)) { $allStrings = false; break; } } if (!$allStrings) { require_once 'Zend/Controller/Dispatcher/Exception.php'; throw new Zend_Controller_Dispatcher_Exception('Word delimiter array must contain only strings'); } return $spec; } require_once 'Zend/Controller/Dispatcher/Exception.php'; throw new Zend_Controller_Dispatcher_Exception('Invalid word delimiter'); } public function getWordDelimiter() { return $this->_wordDelimiter; } public function setWordDelimiter($spec) { $spec = $this->_verifyDelimiter($spec); $this->_wordDelimiter = $spec; return $this; } public function getPathDelimiter() { return $this->_pathDelimiter; } public function setPathDelimiter($spec) { if (!is_string($spec)) { require_once 'Zend/Controller/Dispatcher/Exception.php'; throw new Zend_Controller_Dispatcher_Exception('Invalid path delimiter'); } $this->_pathDelimiter = $spec; return $this; } protected function _formatName($unformatted, $isAction = false) { // preserve directories if (!$isAction) { $segments = explode($this->getPathDelimiter(), $unformatted); } else { $segments = (array) $unformatted; } foreach ($segments as $key => $segment) { $segment = str_replace($this->getWordDelimiter(), ' ', strtolower($segment)); $segment = preg_replace('/[^a-z0-9 ]/', '', $segment); $segments[$key] = str_replace(' ', '', ucwords($segment)); } return implode('_', $segments); } public function getFrontController() { if (null === $this->_frontController) { require_once 'Zend/Controller/Front.php'; $this->_frontController = Zend_Controller_Front::getInstance(); } return $this->_frontController; } public function setFrontController(Zend_Controller_Front $controller) { $this->_frontController = $controller; return $this; } public function setParam($name, $value) { $name = (string) $name; $this->_invokeParams[$name] = $value; return $this; } public function setParams(array $params) { $this->_invokeParams = array_merge($this->_invokeParams, $params); return $this; } public function getParam($name) { if(isset($this->_invokeParams[$name])) { return $this->_invokeParams[$name]; } return null; } public function getParams() { return $this->_invokeParams; } public function clearParams($name = null) { if (null === $name) { $this->_invokeParams = array(); } elseif (is_string($name) && isset($this->_invokeParams[$name])) { unset($this->_invokeParams[$name]); } elseif (is_array($name)) { foreach ($name as $key) { if (is_string($key) && isset($this->_invokeParams[$key])) { unset($this->_invokeParams[$key]); } } } return $this; } public function setResponse(Zend_Controller_Response_Abstract $response = null) { $this->_response = $response; return $this; } public function getResponse() { return $this->_response; } public function setDefaultControllerName($controller) { $this->_defaultController = (string) $controller; return $this; } public function getDefaultControllerName() { return $this->_defaultController; } public function setDefaultAction($action) { $this->_defaultAction = (string) $action; return $this; } public function getDefaultAction() { return $this->_defaultAction; } public function setDefaultModule($module) { $this->_defaultModule = (string) $module; return $this; } public function getDefaultModule() { return $this->_defaultModule; }}ZendFramework继承抽象类Zend_Controller_Dispatcher_Abstract，定义了Zend_Controller_Dispatcher_Standard。Zend_Controller_Dispatcher_Standard是ZendFramework提供的基本的分发器，完成了分发功能。
<?php/** Zend_Loader */require_once 'Zend/Loader.php';/** Zend_Controller_Dispatcher_Abstract */require_once 'Zend/Controller/Dispatcher/Abstract.php';class Zend_Controller_Dispatcher_Standard extends Zend_Controller_Dispatcher_Abstract{ protected $_curDirectory; protected $_curModule; protected $_controllerDirectory = array(); public function __construct(array $params = array()) { parent::__construct($params); $this->_curModule = $this->getDefaultModule(); } public function addControllerDirectory($path, $module = null) { if (null === $module) { $module = $this->_defaultModule; } $module = (string) $module; $path = rtrim((string) $path, '/'); $this->_controllerDirectory[$module] = $path; return $this; } public function setControllerDirectory($directory, $module = null) { $this->_controllerDirectory = array(); if (is_string($directory)) { $this->addControllerDirectory($directory, $module); } elseif (is_array($directory)) { foreach ((array) $directory as $module => $path) { $this->addControllerDirectory($path, $module); } } else { require_once 'Zend/Controller/Exception.php'; throw new Zend_Controller_Exception('Controller directory spec must be either a string or an array'); } return $this; } public function getControllerDirectory($module = null) { if (null === $module) { return $this->_controllerDirectory; } $module = (string) $module; if (array_key_exists($module, $this->_controllerDirectory)) { return $this->_controllerDirectory[$module]; } return null; } public function removeControllerDirectory($module) { $module = (string) $module; if (array_key_exists($module, $this->_controllerDirectory)) { unset($this->_controllerDirectory[$module]); return true; } return false; } public function formatModuleName($unformatted) { if (($this->_defaultModule == $unformatted) && !$this->getParam('prefixDefaultModule')) { return $unformatted; } return ucfirst($this->_formatName($unformatted)); } public function formatClassName($moduleName, $className) { return $this->formatModuleName($moduleName) . '_' . $className; } public function classToFilename($class) { return str_replace('_', DIRECTORY_SEPARATOR, $class) . '.php'; } public function isDispatchable(Zend_Controller_Request_Abstract $request) { $className = $this->getControllerClass($request); if (!$className) { return false; } $finalClass = $className; if (($this->_defaultModule != $this->_curModule) || $this->getParam('prefixDefaultModule')) { $finalClass = $this->formatClassName($this->_curModule, $className); } if (class_exists($finalClass, false)) { return true; } $fileSpec = $this->classToFilename($className); $dispatchDir = $this->getDispatchDirectory(); $test = $dispatchDir . DIRECTORY_SEPARATOR . $fileSpec; return Zend_Loader::isReadable($test); } public function dispatch(Zend_Controller_Request_Abstract $request, Zend_Controller_Response_Abstract $response) { $this->setResponse($response); /** * Get controller class */ if (!$this->isDispatchable($request)) { $controller = $request->getControllerName(); if (!$this->getParam('useDefaultControllerAlways') && !empty($controller)) { require_once 'Zend/Controller/Dispatcher/Exception.php'; throw new Zend_Controller_Dispatcher_Exception('Invalid controller specified (' . $request->getControllerName() . ')'); } $className = $this->getDefaultControllerClass($request); } else { $className = $this->getControllerClass($request); if (!$className) { $className = $this->getDefaultControllerClass($request); } } /** * Load the controller class file */ $className = $this->loadClass($className); /** * Instantiate controller with request, response, and invocation * arguments; throw exception if it's not an action controller */ $controller = new $className($request, $this->getResponse(), $this->getParams()); if (!($controller instanceof Zend_Controller_Action_Interface) && !($controller instanceof Zend_Controller_Action)) { require_once 'Zend/Controller/Dispatcher/Exception.php'; throw new Zend_Controller_Dispatcher_Exception( 'Controller "' . $className . '" is not an instance of Zend_Controller_Action_Interface' ); } /** * Retrieve the action name */ $action = $this->getActionMethod($request); /** * Dispatch the method call */ $request->setDispatched(true); // by default, buffer output $disableOb = $this->getParam('disableOutputBuffering'); $obLevel = ob_get_level(); if (empty($disableOb)) { ob_start(); } try { $controller->dispatch($action); } catch (Exception $e) { // Clean output buffer on error $curObLevel = ob_get_level(); if ($curObLevel > $obLevel) { do { ob_get_clean(); $curObLevel = ob_get_level(); } while ($curObLevel > $obLevel); } throw $e; } if (empty($disableOb)) { $content = ob_get_clean(); $response->appendBody($content); } // Destroy the page controller instance and reflection objects $controller = null; } public function loadClass($className) { $finalClass = $className; if (($this->_defaultModule != $this->_curModule) || $this->getParam('prefixDefaultModule')) { $finalClass = $this->formatClassName($this->_curModule, $className); } if (class_exists($finalClass, false)) { return $finalClass; } $dispatchDir = $this->getDispatchDirectory(); $loadFile = $dispatchDir . DIRECTORY_SEPARATOR . $this->classToFilename($className); if (Zend_Loader::isReadable($loadFile)) { include_once $loadFile; } else { require_once 'Zend/Controller/Dispatcher/Exception.php'; throw new Zend_Controller_Dispatcher_Exception('Cannot load controller class "' . $className . '" from file "' . $loadFile . "'"); } if (!class_exists($finalClass, false)) { require_once 'Zend/Controller/Dispatcher/Exception.php'; throw new Zend_Controller_Dispatcher_Exception('Invalid controller class ("' . $finalClass . '")'); } return $finalClass; } public function getControllerClass(Zend_Controller_Request_Abstract $request) { $controllerName = $request->getControllerName(); if (empty($controllerName)) { if (!$this->getParam('useDefaultControllerAlways')) { return false; } $controllerName = $this->getDefaultControllerName(); $request->setControllerName($controllerName); } $className = $this->formatControllerName($controllerName); $controllerDirs = $this->getControllerDirectory(); $module = $request->getModuleName(); if ($this->isValidModule($module)) { $this->_curModule = $module; $this->_curDirectory = $controllerDirs[$module]; } elseif ($this->isValidModule($this->_defaultModule)) { $request->setModuleName($this->_defaultModule); $this->_curModule = $this->_defaultModule; $this->_curDirectory = $controllerDirs[$this->_defaultModule]; } else { require_once 'Zend/Controller/Exception.php'; throw new Zend_Controller_Exception('No default module defined for this application'); } return $className; } public function isValidModule($module) { if (!is_string($module)) { return false; } $module = strtolower($module); $controllerDir = $this->getControllerDirectory(); foreach (array_keys($controllerDir) as $moduleName) { if ($module == strtolower($moduleName)) { return true; } } return false; } public function getDefaultControllerClass(Zend_Controller_Request_Abstract $request) { $controller = $this->getDefaultControllerName(); $default = $this->formatControllerName($controller); $request->setControllerName($controller) ->setActionName(null); $module = $request->getModuleName(); $controllerDirs = $this->getControllerDirectory(); $this->_curModule = $this->_defaultModule; $this->_curDirectory = $controllerDirs[$this->_defaultModule]; if ($this->isValidModule($module)) { $found = false; if (class_exists($default, false)) { $found = true; } else { $moduleDir = $controllerDirs[$module]; $fileSpec = $moduleDir . DIRECTORY_SEPARATOR . $this->classToFilename($default); if (Zend_Loader::isReadable($fileSpec)) { $found = true; $this->_curDirectory = $moduleDir; } } if ($found) { $request->setModuleName($module); $this->_curModule = $this->formatModuleName($module); } } else { $request->setModuleName($this->_defaultModule); } return $default; } public function getDispatchDirectory() { return $this->_curDirectory; } public function getActionMethod(Zend_Controller_Request_Abstract $request) { $action = $request->getActionName(); if (empty($action)) { $action = $this->getDefaultAction(); $request->setActionName($action); } return $this->formatActionName($action); }}<?php/** Zend_Loader */require_once 'Zend/Loader.php';/** Zend_Controller_Action_HelperBroker */require_once 'Zend/Controller/Action/HelperBroker.php';/** Zend_Controller_Plugin_Broker */require_once 'Zend/Controller/Plugin/Broker.php';class Zend_Controller_Front{ protected $_baseUrl = null; protected $_controllerDir = null; protected $_dispatcher = null; protected static $_instance = null; protected $_invokeParams = array(); protected $_moduleControllerDirectoryName = 'controllers'; protected $_plugins = null; protected $_request = null; protected $_response = null; protected $_returnResponse = false; protected $_router = null; protected $_throwExceptions = false; protected function __construct() { $this->_plugins = new Zend_Controller_Plugin_Broker(); } private function __clone() { } public static function getInstance() { if (null === self::$_instance) { self::$_instance = new self(); } return self::$_instance; } public function resetInstance() { $reflection = new ReflectionObject($this); foreach ($reflection->getProperties() as $property) { $name = $property->getName(); switch ($name) { case '_instance': break; case '_controllerDir': case '_invokeParams': $this->{$name} = array(); break; case '_plugins': $this->{$name} = new Zend_Controller_Plugin_Broker(); break; case '_throwExceptions': case '_returnResponse': $this->{$name} = false; break; case '_moduleControllerDirectoryName': $this->{$name} = 'controllers'; break; default: $this->{$name} = null; break; } } Zend_Controller_Action_HelperBroker::resetHelpers(); } public static function run($controllerDirectory) { self::getInstance() ->setControllerDirectory($controllerDirectory) ->dispatch(); } public function addControllerDirectory($directory, $module = null) { $this->getDispatcher()->addControllerDirectory($directory, $module); return $this; } public function setControllerDirectory($directory, $module = null) { $this->getDispatcher()->setControllerDirectory($directory, $module); return $this; } public function getControllerDirectory($name = null) { return $this->getDispatcher()->getControllerDirectory($name); } public function removeControllerDirectory($module) { return $this->getDispatcher()->removeControllerDirectory($module); } public function addModuleDirectory($path) { try{ $dir = new DirectoryIterator($path); } catch(Exception $e) { require_once 'Zend/Controller/Exception.php'; throw new Zend_Controller_Exception("Directory $path not readable", 0, $e); } foreach ($dir as $file) { if ($file->isDot() || !$file->isDir()) { continue; } $module = $file->getFilename(); // Don't use SCCS directories as modules if (preg_match('/^[^a-z]/i', $module) || ('CVS' == $module)) { continue; } $moduleDir = $file->getPathname() . DIRECTORY_SEPARATOR . $this->getModuleControllerDirectoryName(); $this->addControllerDirectory($moduleDir, $module); } return $this; } public function getModuleDirectory($module = null) { if (null === $module) { $request = $this->getRequest(); if (null !== $request) { $module = $this->getRequest()->getModuleName(); } if (empty($module)) { $module = $this->getDispatcher()->getDefaultModule(); } } $controllerDir = $this->getControllerDirectory($module); if ((null === $controllerDir) || !is_string($controllerDir)) { return null; } return dirname($controllerDir); } public function setModuleControllerDirectoryName($name = 'controllers') { $this->_moduleControllerDirectoryName = (string) $name; return $this; } public function getModuleControllerDirectoryName() { return $this->_moduleControllerDirectoryName; } public function setDefaultControllerName($controller) { $dispatcher = $this->getDispatcher(); $dispatcher->setDefaultControllerName($controller); return $this; } public function getDefaultControllerName() { return $this->getDispatcher()->getDefaultControllerName(); } public function setDefaultAction($action) { $dispatcher = $this->getDispatcher(); $dispatcher->setDefaultAction($action); return $this; } public function getDefaultAction() { return $this->getDispatcher()->getDefaultAction(); } public function setDefaultModule($module) { $dispatcher = $this->getDispatcher(); $dispatcher->setDefaultModule($module); return $this; } public function getDefaultModule() { return $this->getDispatcher()->getDefaultModule(); } public function setRequest($request) { ........................... return $this; } public function getRequest() { return $this->_request; } public function setRouter($router) { .................... return $this; } public function getRouter() { .................. return $this->_router; } public function setBaseUrl($base = null) { .............. return $this; } public function getBaseUrl() { return $this->_baseUrl; } /** * Set the dispatcher object. The dispatcher is responsible for * taking a Zend_Controller_Dispatcher_Token object, instantiating the controller, and * call the action method of the controller. * * @param Zend_Controller_Dispatcher_Interface $dispatcher * @return Zend_Controller_Front */ public function setDispatcher(Zend_Controller_Dispatcher_Interface $dispatcher) { $this->_dispatcher = $dispatcher; return $this; } /** * Return the dispatcher object. * * @return Zend_Controller_Dispatcher_Interface */ public function getDispatcher() { /** * Instantiate the default dispatcher if one was not set. */ if (!$this->_dispatcher instanceof Zend_Controller_Dispatcher_Interface) { require_once 'Zend/Controller/Dispatcher/Standard.php'; $this->_dispatcher = new Zend_Controller_Dispatcher_Standard(); } return $this->_dispatcher; } public function setResponse($response) {.................. return $this; } public function getResponse() { return $this->_response; } public function setParam($name, $value) { $name = (string) $name; $this->_invokeParams[$name] = $value; return $this; } public function setParams(array $params) { $this->_invokeParams = array_merge($this->_invokeParams, $params); return $this; } public function getParam($name) { if(isset($this->_invokeParams[$name])) { return $this->_invokeParams[$name]; } return null; } public function getParams() { return $this->_invokeParams; } public function clearParams($name = null) { if (null === $name) { $this->_invokeParams = array(); } elseif (is_string($name) && isset($this->_invokeParams[$name])) { unset($this->_invokeParams[$name]); } elseif (is_array($name)) { foreach ($name as $key) { if (is_string($key) && isset($this->_invokeParams[$key])) { unset($this->_invokeParams[$key]); } } } return $this; } public function registerPlugin(Zend_Controller_Plugin_Abstract $plugin, $stackIndex = null) { $this->_plugins->registerPlugin($plugin, $stackIndex); return $this; } public function unregisterPlugin($plugin) { $this->_plugins->unregisterPlugin($plugin); return $this; } public function hasPlugin($class) { return $this->_plugins->hasPlugin($class); } public function getPlugin($class) { return $this->_plugins->getPlugin($class); } public function getPlugins() { return $this->_plugins->getPlugins(); } public function throwExceptions($flag = null) { ..................... return $this->_throwExceptions; } public function returnResponse($flag = null) { ................ return $this->_returnResponse; } /** * Dispatch an HTTP request to a controller/action. * * @param Zend_Controller_Request_Abstract|null $request * @param Zend_Controller_Response_Abstract|null $response * @return void|Zend_Controller_Response_Abstract Returns response object if returnResponse() is true */ public function dispatch(Zend_Controller_Request_Abstract $request = null, Zend_Controller_Response_Abstract $response = null) { if (!$this->getParam('noErrorHandler') && !$this->_plugins->hasPlugin('Zend_Controller_Plugin_ErrorHandler')) { // Register with stack index of 100 require_once 'Zend/Controller/Plugin/ErrorHandler.php'; $this->_plugins->registerPlugin(new Zend_Controller_Plugin_ErrorHandler(), 100); } if (!$this->getParam('noViewRenderer') && !Zend_Controller_Action_HelperBroker::hasHelper('viewRenderer')) { require_once 'Zend/Controller/Action/Helper/ViewRenderer.php'; Zend_Controller_Action_HelperBroker::getStack()->offsetSet(-80, new Zend_Controller_Action_Helper_ViewRenderer()); } /** * Instantiate default request object (HTTP version) if none provided */ if (null !== $request) { $this->setRequest($request); } elseif ((null === $request) && (null === ($request = $this->getRequest()))) { require_once 'Zend/Controller/Request/Http.php'; $request = new Zend_Controller_Request_Http(); $this->setRequest($request); } /** * Set base URL of request object, if available */ if (is_callable(array($this->_request, 'setBaseUrl'))) { if (null !== $this->_baseUrl) { $this->_request->setBaseUrl($this->_baseUrl); } } /** * Instantiate default response object (HTTP version) if none provided */ if (null !== $response) { $this->setResponse($response); } elseif ((null === $this->_response) && (null === ($this->_response = $this->getResponse()))) { require_once 'Zend/Controller/Response/Http.php'; $response = new Zend_Controller_Response_Http(); $this->setResponse($response); } /** * Register request and response objects with plugin broker */ $this->_plugins ->setRequest($this->_request) ->setResponse($this->_response); /** * Initialize router */ $router = $this->getRouter(); $router->setParams($this->getParams()); /** * Initialize dispatcher */ $dispatcher = $this->getDispatcher(); $dispatcher->setParams($this->getParams()) ->setResponse($this->_response); // Begin dispatch try { /** * Route request to controller/action, if a router is provided */ /** * Notify plugins of router startup */ $this->_plugins->routeStartup($this->_request); try { $router->route($this->_request); } catch (Exception $e) { if ($this->throwExceptions()) { throw $e; } $this->_response->setException($e); } /** * Notify plugins of router completion */ $this->_plugins->routeShutdown($this->_request); /** * Notify plugins of dispatch loop startup */ $this->_plugins->dispatchLoopStartup($this->_request); /** * Attempt to dispatch the controller/action. If the $this->_request * indicates that it needs to be dispatched, move to the next * action in the request. */ do { $this->_request->setDispatched(true); /** * Notify plugins of dispatch startup */ $this->_plugins->preDispatch($this->_request); /** * Skip requested action if preDispatch() has reset it */ if (!$this->_request->isDispatched()) { continue; } /** * Dispatch request */ try { $dispatcher->dispatch($this->_request, $this->_response); } catch (Exception $e) { if ($this->throwExceptions()) { throw $e; } $this->_response->setException($e); } /** * Notify plugins of dispatch completion */ $this->_plugins->postDispatch($this->_request); } while (!$this->_request->isDispatched()); } catch (Exception $e) { if ($this->throwExceptions()) { throw $e; } $this->_response->setException($e); } /** * Notify plugins of dispatch loop completion */ try { $this->_plugins->dispatchLoopShutdown(); } catch (Exception $e) { if ($this->throwExceptions()) { throw $e; } $this->_response->setException($e); } if ($this->returnResponse()) { return $this->_response; } $this->_response->sendResponse(); }}分发发生在前端控制器中的一个循环（loop）中。分发之前，前端控制器通过路由请求，找到用户指定的模块、控制器、动作和可选参数。然后进入分发循环，分发请求。
分发器需要大量数据完成任务――它需要知道如何格式化控制器和动作的名称，到哪儿找到控制器类文件，模块名是否有效，以及基于其它可用信息判定请求是否能分发的API。
每次迭代（iteration）过程开始时，在请求对象中设置一个标志指示该动作已分发。如果在动作或者前/后分发（pre/postDispatch）插件重置了该标志，分发循环将继续下去并试图分发新的请求。通过改变请求中的控制器或者动作并重置已分发标志，开发人员可以定制执行一个请求链。
控制这种分发过程的动作控制器方法是_forward()；在任意的pre/postDispatch()或者动作中调用该方法，并传入动作、控制器、模块、以及可选的附加参数，就可以进入新的动作。
自定义分发器
Zend_Controller_Dispatcher_Interface定义了下列所有分发器需要实现的方法。
不过大多数情况下，只需要简单地扩展抽象类Zend_Controller_Dispatcher_Abstract，其中已经定义好了上面的大部分方法。或者扩展Zend_Controller_Dispatcher_Standard类，基于标准分发器来修改功能。
需要子类化分发器的可能原因包括：期望在动作控制器中使用不同的类和方法命名模式，或者期望使用不同的分发方式，比如分发到控制器目录下的动作文件，而不是控制器类的动作方法。