ZendFramework教程之分发器Zend_Controller_Dispatcher用法详解_php实例

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

Zend_Controller_Dispatcher_Interface

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();
}

Zend_Controller_Dispatcher_Abstract

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;
  }
}

Zend_Controller_Dispatcher_Standard

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);
  }
}

前端控制器和分发器

<?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();
  }
}

以上对Zend_Controller_Front和Zend_Controller_Dispatcher做了简单的标记，通过分析代码不难看出，基本的运行机制。

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。

更多关于zend相关内容感兴趣的读者可查看本站专题：《Zend FrameWork框架入门教程》、《php优秀开发框架总结》、《Yii框架入门及常用技巧总结》、《ThinkPHP入门教程》、《php面向对象程序设计入门教程》、《php+mysql数据库操作入门教程》及《php常见数据库操作技巧汇总》

希望本文所述对大家PHP程序设计有所帮助。