Zend Framework教程之Zend_Layout布局助手详解

5年以前 | 阅读数：234 次 | 编程语言：PHP

本文实例讲述了Zend Framework教程之Zend_Layout布局助手。分享给大家供大家参考，具体如下：

一、作用

布局的作用和模版的作用类似。可以认为是把网站通用、公共的部分拿出来作为通用的页面框架。例如一个基本的web页面，可能页面的头和尾都是一样，不一样的可能只是内容body部分不一样，可以把公共的部分做成模版。不仅可以提高开发效率，也为后期的维护带来方便。

二、使用

这里举一个简单的例子。

首先用zend studio创建一个基本的zend framework项目：layout_demo1

结构大概如下"

├─.settings
├─application
│ ├─configs
│ ├─controllers
│ ├─models
│ └─views
│ ├─helpers
│ └─scripts
│ ├─error
│ └─index
├─docs
├─library
├─public
└─tests
├─application
│ └─controllers
└─library

1.加入layout功能：

应用配置文件/layout_demo2/application/configs/application.ini，加入如下配置


    resources.frontController.controllerDirectory = APPLICATION_PATH "/controllers"
    resources.frontController.params.displayExceptions = 0
    resources.layout.layoutPath = APPLICATION_PATH "/layouts/scripts/"
    [staging : production]

2.相应的目录和布局模版文件 /layout_demo2/application/layouts/scripts/layout.phtml

├─application
│ ├─configs
│ ├─controllers
│ ├─layouts
│ │ └─scripts
│ ├─models
│ └─views

layout.html类似如下：


    <!doctype html>
    <html>
     <head>
      <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
      <title>my app</title>
      <body>
       <div id="header">
        header
       </div>
       <div id="content">
        <?php echo $this -> layout() -> content;?>
       </div>
       <div id="footer">
        header
       </div>
      </body>
    </html>

这里的


    <?php echo $this -> layout() -> content;?>

是比较重要的。表示此处为布局的内容，也就是会动态变化的地方。

这样，运行一下程序

www.localzend.com/layout_demo1/public/

生成的html源码如下


    <!doctype html>
    <html>
     <head>
      <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
      <title>my app</title>
      <body>
       <div id="header">
        header
       </div>
       <div id="content">
        <style>
     a:link,
     a:visited
     {
      color: #0398CA;
     }
     span#zf-name
     {
      color: #91BE3F;
     }
     div#welcome
     {
      color: #FFFFFF;
      background-image: url(http://framework.zend.com/images/bkg_header.jpg);
      width: 600px;
      height: 400px;
      border: 2px solid #444444;
      overflow: hidden;
      text-align: center;
     }
     div#more-information
     {
      background-image: url(http://framework.zend.com/images/bkg_body-bottom.gif);
      height: 100%;
     }
    </style>
    <div id="welcome">
     <h1>Welcome to the <span id="zf-name">Zend Framework!</span></h1>
     <h3>This is your project's main page</h3>
     <div id="more-information">
      <p><img src="http://framework.zend.com/images/PoweredBy_ZF_4LightBG.png" /></p>
      <p>
       Helpful Links: <br />
       <a href="http://framework.zend.com/">Zend Framework Website</a> |
       <a href="http://framework.zend.com/manual/en/">Zend Framework Manual</a>
      </p>
     </div>
    </div>   </div>
       <div id="footer">
        header
       </div>
      </body>
    </html>

中间部分就是/layout_demo1/application/views/scripts/index/index.phtml的内容。

注入：可以通过zf的命令工具自动生成layout的配置和文件。

命令如下:


    zf enable layout

可以参考命令行章节

三、配置

1.自定义存放位置和名称可以通过application.ini配置文件配置布局文件的存放位置以及布局文件的名称，例如:


    resources.layout.layoutPath = APPLICATION_PATH "/mylayouts/scripts"
    resources.layout.layout = "mylayout"

2.在action中使用layout对象

可以通过


    $layout = $this->_helper->layout();

或者


    $helper = $this->_helper->getHelper('Layout');
    $layout = $helper->getLayoutInstance();

获取布局对象。

可以通过如下方式禁用当前action使用布局模式


    $layout->disableLayout();

可以通过


    $layout->setLayout('other');

来设置使用另一个布局文件

可以通过来传递赋值


    $layout->assign('headertitle', 'app title');
    $layout->somekey = "value"

3.其它获取layout对象的方法

(1)


    $layout = Zend_Layout::getMvcInstance();

(2)


    $layout = $bootstrap->getResource('Layout');

四、其它用法，实现原理

具体其它的使用方法可以参考

Zend_Layout_Controller_Action_Helper_Layout类，
Zend_Layout_Controller_Plugin_Layout类
Zend_View_Helper_Layout类
不言自明。


    <?php
    /** Zend_Controller_Action_Helper_Abstract */
    require_once 'Zend/Controller/Action/Helper/Abstract.php';
    /**
     * Helper for interacting with Zend_Layout objects
     *
     * @uses  Zend_Controller_Action_Helper_Abstract
     * @category Zend
     * @package Zend_Controller
     * @subpackage Zend_Controller_Action
     * @copyright Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
     * @license http://framework.zend.com/license/new-bsd  New BSD License
     */
    class Zend_Layout_Controller_Action_Helper_Layout extends Zend_Controller_Action_Helper_Abstract
    {
     /**
      * @var Zend_Controller_Front
      */
     protected $_frontController;
     /**
      * @var Zend_Layout
      */
     protected $_layout;
     /**
      * @var bool
      */
     protected $_isActionControllerSuccessful = false;
     /**
      * Constructor
      *
      * @param Zend_Layout $layout
      * @return void
      */
     public function __construct(Zend_Layout $layout = null)
     {
      if (null !== $layout) {
       $this->setLayoutInstance($layout);
      } else {
       /**
        * @see Zend_Layout
        */
       require_once 'Zend/Layout.php';
       $layout = Zend_Layout::getMvcInstance();
      }
      if (null !== $layout) {
       $pluginClass = $layout->getPluginClass();
       $front = $this->getFrontController();
       if ($front->hasPlugin($pluginClass)) {
        $plugin = $front->getPlugin($pluginClass);
        $plugin->setLayoutActionHelper($this);
       }
      }
     }
     public function init()
     {
      $this->_isActionControllerSuccessful = false;
     }
     /**
      * Get front controller instance
      *
      * @return Zend_Controller_Front
      */
     public function getFrontController()
     {
      if (null === $this->_frontController) {
       /**
        * @see Zend_Controller_Front
        */
       require_once 'Zend/Controller/Front.php';
       $this->_frontController = Zend_Controller_Front::getInstance();
      }
      return $this->_frontController;
     }
     /**
      * Get layout object
      *
      * @return Zend_Layout
      */
     public function getLayoutInstance()
     {
      if (null === $this->_layout) {
       /**
        * @see Zend_Layout
        */
       require_once 'Zend/Layout.php';
       if (null === ($this->_layout = Zend_Layout::getMvcInstance())) {
        $this->_layout = new Zend_Layout();
       }
      }
      return $this->_layout;
     }
     /**
      * Set layout object
      *
      * @param Zend_Layout $layout
      * @return Zend_Layout_Controller_Action_Helper_Layout
      */
     public function setLayoutInstance(Zend_Layout $layout)
     {
      $this->_layout = $layout;
      return $this;
     }
     /**
      * Mark Action Controller (according to this plugin) as Running successfully
      *
      * @return Zend_Layout_Controller_Action_Helper_Layout
      */
     public function postDispatch()
     {
      $this->_isActionControllerSuccessful = true;
      return $this;
     }
     /**
      * Did the previous action successfully complete?
      *
      * @return bool
      */
     public function isActionControllerSuccessful()
     {
      return $this->_isActionControllerSuccessful;
     }
     /**
      * Strategy pattern; call object as method
      *
      * Returns layout object
      *
      * @return Zend_Layout
      */
     public function direct()
     {
      return $this->getLayoutInstance();
     }
     /**
      * Proxy method calls to layout object
      *
      * @param string $method
      * @param array $args
      * @return mixed
      */
     public function __call($method, $args)
     {
      $layout = $this->getLayoutInstance();
      if (method_exists($layout, $method)) {
       return call_user_func_array(array($layout, $method), $args);
      }
      require_once 'Zend/Layout/Exception.php';
      throw new Zend_Layout_Exception(sprintf("Invalid method '%s' called on layout action helper", $method));
     }
    }


    <?php
    /** Zend_Controller_Plugin_Abstract */
    require_once 'Zend/Controller/Plugin/Abstract.php';
    /**
     * Render layouts
     *
     * @uses  Zend_Controller_Plugin_Abstract
     * @category Zend
     * @package Zend_Controller
     * @subpackage Plugins
     * @copyright Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
     * @license http://framework.zend.com/license/new-bsd  New BSD License
     * @version $Id: Layout.php 23775 2011-03-01 17:25:24Z ralph $
     */
    class Zend_Layout_Controller_Plugin_Layout extends Zend_Controller_Plugin_Abstract
    {
     protected $_layoutActionHelper = null;
     /**
      * @var Zend_Layout
      */
     protected $_layout;
     /**
      * Constructor
      *
      * @param Zend_Layout $layout
      * @return void
      */
     public function __construct(Zend_Layout $layout = null)
     {
      if (null !== $layout) {
       $this->setLayout($layout);
      }
     }
     /**
      * Retrieve layout object
      *
      * @return Zend_Layout
      */
     public function getLayout()
     {
      return $this->_layout;
     }
     /**
      * Set layout object
      *
      * @param Zend_Layout $layout
      * @return Zend_Layout_Controller_Plugin_Layout
      */
     public function setLayout(Zend_Layout $layout)
     {
      $this->_layout = $layout;
      return $this;
     }
     /**
      * Set layout action helper
      *
      * @param Zend_Layout_Controller_Action_Helper_Layout $layoutActionHelper
      * @return Zend_Layout_Controller_Plugin_Layout
      */
     public function setLayoutActionHelper(Zend_Layout_Controller_Action_Helper_Layout $layoutActionHelper)
     {
      $this->_layoutActionHelper = $layoutActionHelper;
      return $this;
     }
     /**
      * Retrieve layout action helper
      *
      * @return Zend_Layout_Controller_Action_Helper_Layout
      */
     public function getLayoutActionHelper()
     {
      return $this->_layoutActionHelper;
     }
     /**
      * postDispatch() plugin hook -- render layout
      *
      * @param Zend_Controller_Request_Abstract $request
      * @return void
      */
     public function postDispatch(Zend_Controller_Request_Abstract $request)
     {
      $layout = $this->getLayout();
      $helper = $this->getLayoutActionHelper();
      // Return early if forward detected
      if (!$request->isDispatched()
       || $this->getResponse()->isRedirect()
       || ($layout->getMvcSuccessfulActionOnly()
        && (!empty($helper) && !$helper->isActionControllerSuccessful())))
      {
       return;
      }
      // Return early if layout has been disabled
      if (!$layout->isEnabled()) {
       return;
      }
      $response = $this->getResponse();
      $content = $response->getBody(true);
      $contentKey = $layout->getContentKey();
      if (isset($content['default'])) {
       $content[$contentKey] = $content['default'];
      }
      if ('default' != $contentKey) {
       unset($content['default']);
      }
      $layout->assign($content);
      $fullContent = null;
      $obStartLevel = ob_get_level();
      try {
       $fullContent = $layout->render();
       $response->setBody($fullContent);
      } catch (Exception $e) {
       while (ob_get_level() > $obStartLevel) {
        $fullContent .= ob_get_clean();
       }
       $request->setParam('layoutFullContent', $fullContent);
       $request->setParam('layoutContent', $layout->content);
       $response->setBody(null);
       throw $e;
      }
     }
    }


    <?php
    /** Zend_View_Helper_Abstract.php */
    require_once 'Zend/View/Helper/Abstract.php';
    /**
     * View helper for retrieving layout object
     *
     * @package Zend_View
     * @subpackage Helper
     * @copyright Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
     * @license http://framework.zend.com/license/new-bsd  New BSD License
     */
    class Zend_View_Helper_Layout extends Zend_View_Helper_Abstract
    {
     /** @var Zend_Layout */
     protected $_layout;
     /**
      * Get layout object
      *
      * @return Zend_Layout
      */
     public function getLayout()
     {
      if (null === $this->_layout) {
       require_once 'Zend/Layout.php';
       $this->_layout = Zend_Layout::getMvcInstance();
       if (null === $this->_layout) {
        // Implicitly creates layout object
        $this->_layout = new Zend_Layout();
       }
      }
      return $this->_layout;
     }
     /**
      * Set layout object
      *
      * @param Zend_Layout $layout
      * @return Zend_Layout_Controller_Action_Helper_Layout
      */
     public function setLayout(Zend_Layout $layout)
     {
      $this->_layout = $layout;
      return $this;
     }
     /**
      * Return layout object
      *
      * Usage: $this->layout()->setLayout('alternate');
      *
      * @return Zend_Layout
      */
     public function layout()
     {
      return $this->getLayout();
     }
    }

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。