File indexing completed on 2024-12-22 05:37:17

 <?php
 /**
  * Zend Framework
  *
  * LICENSE
  *
  * This source file is subject to the new BSD license that is bundled
  * with this package in the file LICENSE.txt.
  * It is also available through the world-wide-web at this URL:
  * http://framework.zend.com/license/new-bsd
  * If you did not receive a copy of the license and are unable to
  * obtain it through the world-wide-web, please send an email
  * to license@zend.com so we can send you a copy immediately.
  *
  * @category   Zend
  * @package    Zend_Paginator
  * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  * @version    $Id$
  */
 
 /**
  * @see Zend_Loader_PluginLoader
  */
 // require_once 'Zend/Loader/PluginLoader.php';
 
 /**
  * @see Zend_Json
  */
 // require_once 'Zend/Json.php';
 
 /**
  * @category   Zend
  * @package    Zend_Paginator
  * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  */
 class Zend_Paginator implements Countable, IteratorAggregate
 {
     /**
      * Specifies that the factory should try to detect the proper adapter type first
      *
      * @var string
      */
     const INTERNAL_ADAPTER = 'Zend_Paginator_Adapter_Internal';
 
     /**
      * The cache tag prefix used to namespace Paginator results in the cache
      *
      */
     const CACHE_TAG_PREFIX = 'Zend_Paginator_';
 
     /**
      * Adapter plugin loader
      *
      * @var Zend_Loader_PluginLoader
      */
     protected static $_adapterLoader = null;
 
     /**
      * Configuration file
      *
      * @var Zend_Config
      */
     protected static $_config = null;
 
     /**
      * Default scrolling style
      *
      * @var string
      */
     protected static $_defaultScrollingStyle = 'Sliding';
 
     /**
      * Default item count per page
      *
      * @var int
      */
     protected static $_defaultItemCountPerPage = 10;
 
     /**
      * Default number of local pages (i.e., the number of discretes
      * page numbers that will be displayed, including the current
      * page number)
      *
      * @var int
      */
     protected static $_defaultPageRange = 10;
 
     /**
      * Scrolling style plugin loader
      *
      * @var Zend_Loader_PluginLoader
      */
     protected static $_scrollingStyleLoader = null;
 
     /**
      * Cache object
      *
      * @var Zend_Cache_Core
      */
     protected static $_cache;
 
     /**
      * Enable or disable the cache by Zend_Paginator instance
      *
      * @var bool
      */
     protected $_cacheEnabled = true;
 
     /**
      * Adapter
      *
      * @var Zend_Paginator_Adapter_Interface
      */
     protected $_adapter = null;
 
     /**
      * Number of items in the current page
      *
      * @var integer
      */
     protected $_currentItemCount = null;
 
     /**
      * Current page items
      *
      * @var Traversable
      */
     protected $_currentItems = null;
 
     /**
      * Current page number (starting from 1)
      *
      * @var integer
      */
     protected $_currentPageNumber = 1;
 
     /**
      * Result filter
      *
      * @var Zend_Filter_Interface
      */
     protected $_filter = null;
 
     /**
      * Number of items per page
      *
      * @var integer
      */
     protected $_itemCountPerPage = null;
 
     /**
      * Number of pages
      *
      * @var integer
      */
     protected $_pageCount = null;
 
     /**
      * Number of local pages (i.e., the number of discrete page numbers
      * that will be displayed, including the current page number)
      *
      * @var integer
      */
     protected $_pageRange = null;
 
     /**
      * Pages
      *
      * @var array
      */
     protected $_pages = null;
 
     /**
      * View instance used for self rendering
      *
      * @var Zend_View_Interface
      */
     protected $_view = null;
 
     /**
      * Adds an adapter prefix path to the plugin loader.
      *
      * @param string $prefix
      * @param string $path
      */
     public static function addAdapterPrefixPath($prefix, $path)
     {
         self::getAdapterLoader()->addPrefixPath($prefix, $path);
     }
 
     /**
      * Adds an array of adapter prefix paths to the plugin
      * loader.
      *
      * <code>
      * $prefixPaths = array(
      *     'My_Paginator_Adapter'   => 'My/Paginator/Adapter/',
      *     'Your_Paginator_Adapter' => 'Your/Paginator/Adapter/'
      * );
      * </code>
      *
      * @param array $prefixPaths
      */
     public static function addAdapterPrefixPaths(array $prefixPaths)
     {
         if (isset($prefixPaths['prefix']) && isset($prefixPaths['path'])) {
             self::addAdapterPrefixPath($prefixPaths['prefix'], $prefixPaths['path']);
         } else {
             foreach ($prefixPaths as $prefix => $path) {
                 if (is_array($path) && isset($path['prefix']) && isset($path['path'])) {
                     $prefix = $path['prefix'];
                     $path   = $path['path'];
                 }
 
                 self::addAdapterPrefixPath($prefix, $path);
             }
         }
     }
 
     /**
      * Adds a scrolling style prefix path to the plugin loader.
      *
      * @param string $prefix
      * @param string $path
      */
     public static function addScrollingStylePrefixPath($prefix, $path)
     {
         self::getScrollingStyleLoader()->addPrefixPath($prefix, $path);
     }
 
     /**
      * Adds an array of scrolling style prefix paths to the plugin
      * loader.
      *
      * <code>
      * $prefixPaths = array(
      *     'My_Paginator_ScrollingStyle'   => 'My/Paginator/ScrollingStyle/',
      *     'Your_Paginator_ScrollingStyle' => 'Your/Paginator/ScrollingStyle/'
      * );
      * </code>
      *
      * @param array $prefixPaths
      */
     public static function addScrollingStylePrefixPaths(array $prefixPaths)
     {
         if (isset($prefixPaths['prefix']) && isset($prefixPaths['path'])) {
             self::addScrollingStylePrefixPath($prefixPaths['prefix'], $prefixPaths['path']);
         } else {
             foreach ($prefixPaths as $prefix => $path) {
                 if (is_array($path) && isset($path['prefix']) && isset($path['path'])) {
                     $prefix = $path['prefix'];
                     $path   = $path['path'];
                 }
 
                 self::addScrollingStylePrefixPath($prefix, $path);
             }
         }
     }
 
     /**
      * Factory.
      *
      * @param  mixed $data
      * @param  string $adapter
      * @param  array $prefixPaths
      * @return Zend_Paginator
      */
     public static function factory($data, $adapter = self::INTERNAL_ADAPTER,
                                    array $prefixPaths = null)
     {
         if ($data instanceof Zend_Paginator_AdapterAggregate) {
             return new self($data->getPaginatorAdapter());
         } else {
             if ($adapter == self::INTERNAL_ADAPTER) {
                 if (is_array($data)) {
                     $adapter = 'Array';
                 } else if ($data instanceof Zend_Db_Table_Select) {
                     $adapter = 'DbTableSelect';
                 } else if ($data instanceof Zend_Db_Select) {
                     $adapter = 'DbSelect';
                 } else if ($data instanceof Iterator) {
                     $adapter = 'Iterator';
                 } else if (is_integer($data)) {
                     $adapter = 'Null';
                 } else {
                     $type = (is_object($data)) ? get_class($data) : gettype($data);
 
                     /**
                      * @see Zend_Paginator_Exception
                      */
                     // require_once 'Zend/Paginator/Exception.php';
 
                     throw new Zend_Paginator_Exception('No adapter for type ' . $type);
                 }
             }
 
             $pluginLoader = self::getAdapterLoader();
 
             if (null !== $prefixPaths) {
                 foreach ($prefixPaths as $prefix => $path) {
                     $pluginLoader->addPrefixPath($prefix, $path);
                 }
             }
 
             $adapterClassName = $pluginLoader->load($adapter);
 
             return new self(new $adapterClassName($data));
         }
     }
 
     /**
      * Returns the adapter loader.  If it doesn't exist it's created.
      *
      * @return Zend_Loader_PluginLoader
      */
     public static function getAdapterLoader()
     {
         if (self::$_adapterLoader === null) {
             self::$_adapterLoader = new Zend_Loader_PluginLoader(
                 array('Zend_Paginator_Adapter' => 'Zend/Paginator/Adapter')
             );
         }
 
         return self::$_adapterLoader;
     }
 
     /**
      * Set a global config
      *
      * @param Zend_Config $config
      */
     public static function setConfig(Zend_Config $config)
     {
         self::$_config = $config;
 
         $adapterPaths = $config->get('adapterpaths');
 
         if ($adapterPaths != null) {
             self::addAdapterPrefixPaths($adapterPaths->adapterpath->toArray());
         }
 
         $prefixPaths = $config->get('prefixpaths');
 
         if ($prefixPaths != null) {
             self::addScrollingStylePrefixPaths($prefixPaths->prefixpath->toArray());
         }
 
         $scrollingStyle = $config->get('scrollingstyle');
 
         if ($scrollingStyle != null) {
             self::setDefaultScrollingStyle($scrollingStyle);
         }
     }
 
     /**
      * Returns the default scrolling style.
      *
      * @return  string
      */
     public static function getDefaultScrollingStyle()
     {
         return self::$_defaultScrollingStyle;
     }
 
     /**
      * Get the default item count per page
      *
      * @return int
      */
     public static function getDefaultItemCountPerPage()
     {
         return self::$_defaultItemCountPerPage;
     }
 
     /**
      * Set the default item count per page
      *
      * @param int $count
      */
     public static function setDefaultItemCountPerPage($count)
     {
         self::$_defaultItemCountPerPage = (int) $count;
     }
 
     /**
      * Get the default page range
      *
      * @return int
      */
     public static function getDefaultPageRange()
     {
         return self::$_defaultPageRange;
     }
 
     /**
      * Set the default page range
      *
      * @param int $count
      */
     public static function setDefaultPageRange($count)
     {
         self::$_defaultPageRange = (int) $count;
     }
 
     /**
      * Sets a cache object
      *
      * @param Zend_Cache_Core $cache
      */
     public static function setCache(Zend_Cache_Core $cache)
     {
         self::$_cache = $cache;
     }
 
     /**
      * Sets the default scrolling style.
      *
      * @param  string $scrollingStyle
      */
     public static function setDefaultScrollingStyle($scrollingStyle = 'Sliding')
     {
         self::$_defaultScrollingStyle = $scrollingStyle;
     }
 
     /**
      * Returns the scrolling style loader.  If it doesn't exist it's
      * created.
      *
      * @return Zend_Loader_PluginLoader
      */
     public static function getScrollingStyleLoader()
     {
         if (self::$_scrollingStyleLoader === null) {
             self::$_scrollingStyleLoader = new Zend_Loader_PluginLoader(
                 array('Zend_Paginator_ScrollingStyle' => 'Zend/Paginator/ScrollingStyle')
             );
         }
 
         return self::$_scrollingStyleLoader;
     }
 
     /**
      * Constructor.
      *
      * @param Zend_Paginator_Adapter_Interface|Zend_Paginator_AdapterAggregate $adapter
      */
     public function __construct($adapter)
     {
         if ($adapter instanceof Zend_Paginator_Adapter_Interface) {
             $this->_adapter = $adapter;
         } else if ($adapter instanceof Zend_Paginator_AdapterAggregate) {
             $this->_adapter = $adapter->getPaginatorAdapter();
         } else {
             /**
              * @see Zend_Paginator_Exception
              */
             // require_once 'Zend/Paginator/Exception.php';
 
             throw new Zend_Paginator_Exception(
                 'Zend_Paginator only accepts instances of the type ' .
                 'Zend_Paginator_Adapter_Interface or Zend_Paginator_AdapterAggregate.'
             );
         }
 
         $config = self::$_config;
 
         if ($config != null) {
             $setupMethods = array('ItemCountPerPage', 'PageRange');
 
             foreach ($setupMethods as $setupMethod) {
                 $value = $config->get(strtolower($setupMethod));
 
                 if ($value != null) {
                     $setupMethod = 'set' . $setupMethod;
                     $this->$setupMethod($value);
                 }
             }
         }
     }
 
     /**
      * Serializes the object as a string.  Proxies to {@link render()}.
      *
      * @return string
      */
     public function __toString()
     {
         try {
             $return = $this->render();
             return $return;
         } catch (Exception $e) {
             trigger_error($e->getMessage(), E_USER_WARNING);
         }
 
         return '';
     }
 
     /**
      * Enables/Disables the cache for this instance
      *
      * @param bool $enable
      * @return Zend_Paginator
      */
     public function setCacheEnabled($enable)
     {
         $this->_cacheEnabled = (bool)$enable;
         return $this;
     }
 
     /**
      * Returns the number of pages.
      *
      * @return integer
      */
     public function count()
     {
         if (!$this->_pageCount) {
             $this->_pageCount = $this->_calculatePageCount();
         }
 
         return $this->_pageCount;
     }
 
     /**
      * Returns the total number of items available.  Uses cache if caching is enabled.
      *
      * @return integer
      */
     public function getTotalItemCount()
     {
         if (!$this->_cacheEnabled()) {
             return count($this->getAdapter());
         } else {
             $cacheId   = md5($this->_getCacheInternalId(). '_itemCount');            
             $itemCount = self::$_cache->load($cacheId);
 
             if ($itemCount === false) {
                 $itemCount = count($this->getAdapter());
 
                 self::$_cache->save($itemCount, $cacheId, array($this->_getCacheInternalId()));
             }
             
             return $itemCount;
         }
     }
 
     /**
      * Clear the page item cache.
      *
      * @param int $pageNumber
      * @return Zend_Paginator
      */
     public function clearPageItemCache($pageNumber = null)
     {
         if (!$this->_cacheEnabled()) {
             return $this;
         }
 
         if (null === $pageNumber) {
             foreach (self::$_cache->getIdsMatchingTags(array($this->_getCacheInternalId())) as $id) {
                 if (preg_match('|'.self::CACHE_TAG_PREFIX."(\d+)_.*|", $id, $page)) {
                     self::$_cache->remove($this->_getCacheId($page[1]));
                 }
             }
         } else {
             $cleanId = $this->_getCacheId($pageNumber);
             self::$_cache->remove($cleanId);
         }
         return $this;
     }
 
     /**
      * Returns the absolute item number for the specified item.
      *
      * @param  integer $relativeItemNumber Relative item number
      * @param  integer $pageNumber Page number
      * @return integer
      */
     public function getAbsoluteItemNumber($relativeItemNumber, $pageNumber = null)
     {
         $relativeItemNumber = $this->normalizeItemNumber($relativeItemNumber);
 
         if ($pageNumber == null) {
             $pageNumber = $this->getCurrentPageNumber();
         }
 
         $pageNumber = $this->normalizePageNumber($pageNumber);
 
         return (($pageNumber - 1) * $this->getItemCountPerPage()) + $relativeItemNumber;
     }
 
     /**
      * Returns the adapter.
      *
      * @return Zend_Paginator_Adapter_Interface
      */
     public function getAdapter()
     {
         return $this->_adapter;
     }
 
     /**
      * Returns the number of items for the current page.
      *
      * @return integer
      */
     public function getCurrentItemCount()
     {
         if ($this->_currentItemCount === null) {
             $this->_currentItemCount = $this->getItemCount($this->getCurrentItems());
         }
 
         return $this->_currentItemCount;
     }
 
     /**
      * Returns the items for the current page.
      *
      * @return Traversable
      */
     public function getCurrentItems()
     {
         if ($this->_currentItems === null) {
             $this->_currentItems = $this->getItemsByPage($this->getCurrentPageNumber());
         }
 
         return $this->_currentItems;
     }
 
     /**
      * Returns the current page number.
      *
      * @return integer
      */
     public function getCurrentPageNumber()
     {
         return $this->normalizePageNumber($this->_currentPageNumber);
     }
 
     /**
      * Sets the current page number.
      *
      * @param  integer $pageNumber Page number
      * @return Zend_Paginator $this
      */
     public function setCurrentPageNumber($pageNumber)
     {
         $this->_currentPageNumber = (integer) $pageNumber;
         $this->_currentItems      = null;
         $this->_currentItemCount  = null;
 
         return $this;
     }
 
     /**
      * Get the filter
      *
      * @return Zend_Filter_Interface
      */
     public function getFilter()
     {
         return $this->_filter;
     }
 
     /**
      * Set a filter chain
      *
      * @param Zend_Filter_Interface $filter
      * @return Zend_Paginator
      */
     public function setFilter(Zend_Filter_Interface $filter)
     {
         $this->_filter = $filter;
 
         return $this;
     }
 
     /**
      * Returns an item from a page.  The current page is used if there's no
      * page sepcified.
      *
      * @param  integer $itemNumber Item number (1 to itemCountPerPage)
      * @param  integer $pageNumber
      * @return mixed
      */
     public function getItem($itemNumber, $pageNumber = null)
     {
         if ($pageNumber == null) {
             $pageNumber = $this->getCurrentPageNumber();
         } else if ($pageNumber < 0) {
             $pageNumber = ($this->count() + 1) + $pageNumber;
         }
 
         $page = $this->getItemsByPage($pageNumber);
         $itemCount = $this->getItemCount($page);
 
         if ($itemCount == 0) {
             /**
              * @see Zend_Paginator_Exception
              */
             // require_once 'Zend/Paginator/Exception.php';
 
             throw new Zend_Paginator_Exception('Page ' . $pageNumber . ' does not exist');
         }
 
         if ($itemNumber < 0) {
             $itemNumber = ($itemCount + 1) + $itemNumber;
         }
 
         $itemNumber = $this->normalizeItemNumber($itemNumber);
 
         if ($itemNumber > $itemCount) {
             /**
              * @see Zend_Paginator_Exception
              */
             // require_once 'Zend/Paginator/Exception.php';
 
             throw new Zend_Paginator_Exception('Page ' . $pageNumber . ' does not'
                                              . ' contain item number ' . $itemNumber);
         }
 
         return $page[$itemNumber - 1];
     }
 
     /**
      * Returns the number of items per page.
      *
      * @return integer
      */
     public function getItemCountPerPage()
     {
         if (empty($this->_itemCountPerPage)) {
             $this->_itemCountPerPage = self::getDefaultItemCountPerPage();
         }
 
         return $this->_itemCountPerPage;
     }
 
     /**
      * Sets the number of items per page.
      *
      * @param  integer $itemCountPerPage
      * @return Zend_Paginator $this
      */
     public function setItemCountPerPage($itemCountPerPage = -1)
     {
         $this->_itemCountPerPage = (integer) $itemCountPerPage;
         if ($this->_itemCountPerPage < 1) {
             $this->_itemCountPerPage = $this->getTotalItemCount();
         }
         $this->_pageCount        = $this->_calculatePageCount();
         $this->_currentItems     = null;
         $this->_currentItemCount = null;
 
         return $this;
     }
 
     /**
      * Returns the number of items in a collection.
      *
      * @param  mixed $items Items
      * @return integer
      */
     public function getItemCount($items)
     {
         $itemCount = 0;
 
         if (is_array($items) || $items instanceof Countable) {
             $itemCount = count($items);
         } else { // $items is something like LimitIterator
             $itemCount = iterator_count($items);
         }
 
         return $itemCount;
     }
 
     /**
      * Returns the items for a given page.
      *
      * @return Traversable
      */
     public function getItemsByPage($pageNumber)
     {
         $pageNumber = $this->normalizePageNumber($pageNumber);
 
         if ($this->_cacheEnabled()) {
             $data = self::$_cache->load($this->_getCacheId($pageNumber));
             if ($data !== false) {
                 return $data;
             }
         }
 
         $offset = ($pageNumber - 1) * $this->getItemCountPerPage();
 
         $items = $this->_adapter->getItems($offset, $this->getItemCountPerPage());
 
         $filter = $this->getFilter();
 
         if ($filter !== null) {
             $items = $filter->filter($items);
         }
 
         if (!$items instanceof Traversable) {
             $items = new ArrayIterator($items);
         }
 
         if ($this->_cacheEnabled()) {
             self::$_cache->save($items, $this->_getCacheId($pageNumber), array($this->_getCacheInternalId()));
         }
 
         return $items;
     }
 
     /**
      * Returns a foreach-compatible iterator.
      *
      * @return Traversable
      */
     public function getIterator()
     {
         return $this->getCurrentItems();
     }
 
     /**
      * Returns the page range (see property declaration above).
      *
      * @return integer
      */
     public function getPageRange()
     {
         if (null === $this->_pageRange) {
             $this->_pageRange = self::getDefaultPageRange();
         }
 
         return $this->_pageRange;
     }
 
     /**
      * Sets the page range (see property declaration above).
      *
      * @param  integer $pageRange
      * @return Zend_Paginator $this
      */
     public function setPageRange($pageRange)
     {
         $this->_pageRange = (integer) $pageRange;
 
         return $this;
     }
 
     /**
      * Returns the page collection.
      *
      * @param  string $scrollingStyle Scrolling style
      * @return array
      */
     public function getPages($scrollingStyle = null)
     {
         if ($this->_pages === null) {
             $this->_pages = $this->_createPages($scrollingStyle);
         }
 
         return $this->_pages;
     }
 
     /**
      * Returns a subset of pages within a given range.
      *
      * @param  integer $lowerBound Lower bound of the range
      * @param  integer $upperBound Upper bound of the range
      * @return array
      */
     public function getPagesInRange($lowerBound, $upperBound)
     {
         $lowerBound = $this->normalizePageNumber($lowerBound);
         $upperBound = $this->normalizePageNumber($upperBound);
 
         $pages = array();
 
         for ($pageNumber = $lowerBound; $pageNumber <= $upperBound; $pageNumber++) {
             $pages[$pageNumber] = $pageNumber;
         }
 
         return $pages;
     }
 
     /**
      * Returns the page item cache.
      *
      * @return array
      */
     public function getPageItemCache()
     {
         $data = array();
         if ($this->_cacheEnabled()) {
             foreach (self::$_cache->getIdsMatchingTags(array($this->_getCacheInternalId())) as $id) {
                     if (preg_match('|'.self::CACHE_TAG_PREFIX."(\d+)_.*|", $id, $page)) {
                         $data[$page[1]] = self::$_cache->load($this->_getCacheId($page[1]));
                     }
             }
         }
         return $data;
     }
 
     /**
      * Retrieves the view instance.  If none registered, attempts to pull f
      * rom ViewRenderer.
      *
      * @return Zend_View_Interface|null
      */
     public function getView()
     {
         if ($this->_view === null) {
             /**
              * @see Zend_Controller_Action_HelperBroker
              */
             // require_once 'Zend/Controller/Action/HelperBroker.php';
 
             $viewRenderer = Zend_Controller_Action_HelperBroker::getStaticHelper('viewRenderer');
             if ($viewRenderer->view === null) {
                 $viewRenderer->initView();
             }
             $this->_view = $viewRenderer->view;
         }
 
         return $this->_view;
     }
 
     /**
      * Sets the view object.
      *
      * @param  Zend_View_Interface $view
      * @return Zend_Paginator
      */
     public function setView(Zend_View_Interface $view = null)
     {
         $this->_view = $view;
 
         return $this;
     }
 
     /**
      * Brings the item number in range of the page.
      *
      * @param  integer $itemNumber
      * @return integer
      */
     public function normalizeItemNumber($itemNumber)
     {
         $itemNumber = (integer) $itemNumber;
 
         if ($itemNumber < 1) {
             $itemNumber = 1;
         }
 
         if ($itemNumber > $this->getItemCountPerPage()) {
             $itemNumber = $this->getItemCountPerPage();
         }
 
         return $itemNumber;
     }
 
     /**
      * Brings the page number in range of the paginator.
      *
      * @param  integer $pageNumber
      * @return integer
      */
     public function normalizePageNumber($pageNumber)
     {
         $pageNumber = (integer) $pageNumber;
 
         if ($pageNumber < 1) {
             $pageNumber = 1;
         }
 
         $pageCount = $this->count();
 
         if ($pageCount > 0 && $pageNumber > $pageCount) {
             $pageNumber = $pageCount;
         }
 
         return $pageNumber;
     }
 
     /**
      * Renders the paginator.
      *
      * @param  Zend_View_Interface $view
      * @return string
      */
     public function render(Zend_View_Interface $view = null)
     {
         if (null !== $view) {
             $this->setView($view);
         }
 
         $view = $this->getView();
 
         return $view->paginationControl($this);
     }
 
     /**
      * Returns the items of the current page as JSON.
      *
      * @return string
      */
     public function toJson()
     {
         $currentItems = $this->getCurrentItems();
 
         if ($currentItems instanceof Zend_Db_Table_Rowset_Abstract) {
             return Zend_Json::encode($currentItems->toArray());
         } else {
             return Zend_Json::encode($currentItems);
         }
     }
 
     /**
      * Tells if there is an active cache object
      * and if the cache has not been desabled
      *
      * @return bool
      */
     protected function _cacheEnabled()
     {
         return ((self::$_cache !== null) && $this->_cacheEnabled);
     }
 
     /**
      * Makes an Id for the cache
      * Depends on the adapter object and the page number
      *
      * Used to store item in cache from that Paginator instance
      *  and that current page
      *
      * @param int $page
      * @return string
      */
     protected function _getCacheId($page = null)
     {
         if ($page === null) {
             $page = $this->getCurrentPageNumber();
         }
         return self::CACHE_TAG_PREFIX . $page . '_' . $this->_getCacheInternalId();
     }
 
     /**
      * Get the internal cache id
      * Depends on the adapter and the item count per page
      *
      * Used to tag that unique Paginator instance in cache
      *
      * @return string
      */
     protected function _getCacheInternalId()
     {
         $adapter = $this->getAdapter();
         
         if (method_exists($adapter, 'getCacheIdentifier')) {
             return md5(serialize(array(
                 $adapter->getCacheIdentifier(), $this->getItemCountPerPage()
             )));
         } else {
             return md5(serialize(array(
                 $adapter,
                 $this->getItemCountPerPage()
             )));
         }
     }
 
     /**
      * Calculates the page count.
      *
      * @return integer
      */
     protected function _calculatePageCount()
     {
         return (integer) ceil($this->getTotalItemCount() / $this->getItemCountPerPage());
     }
 
     /**
      * Creates the page collection.
      *
      * @param  string $scrollingStyle Scrolling style
      * @return stdClass
      */
     protected function _createPages($scrollingStyle = null)
     {
         $pageCount         = $this->count();
         $currentPageNumber = $this->getCurrentPageNumber();
 
         $pages = new stdClass();
         $pages->pageCount        = $pageCount;
         $pages->itemCountPerPage = $this->getItemCountPerPage();
         $pages->first            = 1;
         $pages->current          = $currentPageNumber;
         $pages->last             = $pageCount;
 
         // Previous and next
         if ($currentPageNumber - 1 > 0) {
             $pages->previous = $currentPageNumber - 1;
         }
 
         if ($currentPageNumber + 1 <= $pageCount) {
             $pages->next = $currentPageNumber + 1;
         }
 
         // Pages in range
         $scrollingStyle = $this->_loadScrollingStyle($scrollingStyle);
         $pages->pagesInRange     = $scrollingStyle->getPages($this);
         $pages->firstPageInRange = min($pages->pagesInRange);
         $pages->lastPageInRange  = max($pages->pagesInRange);
 
         // Item numbers
         if ($this->getCurrentItems() !== null) {
             $pages->currentItemCount = $this->getCurrentItemCount();
             $pages->itemCountPerPage = $this->getItemCountPerPage();
             $pages->totalItemCount   = $this->getTotalItemCount();
             $pages->firstItemNumber  = (($currentPageNumber - 1) * $this->getItemCountPerPage()) + 1;
             $pages->lastItemNumber   = $pages->firstItemNumber + $pages->currentItemCount - 1;
         }
 
         return $pages;
     }
 
     /**
      * Loads a scrolling style.
      *
      * @param string $scrollingStyle
      * @return Zend_Paginator_ScrollingStyle_Interface
      */
     protected function _loadScrollingStyle($scrollingStyle = null)
     {
         if ($scrollingStyle === null) {
             $scrollingStyle = self::$_defaultScrollingStyle;
         }
 
         switch (strtolower(gettype($scrollingStyle))) {
             case 'object':
                 if (!$scrollingStyle instanceof Zend_Paginator_ScrollingStyle_Interface) {
                     /**
                      * @see Zend_View_Exception
                      */
                     // require_once 'Zend/View/Exception.php';
 
                     throw new Zend_View_Exception('Scrolling style must implement ' .
                         'Zend_Paginator_ScrollingStyle_Interface');
                 }
 
                 return $scrollingStyle;
 
             case 'string':
                 $className = self::getScrollingStyleLoader()->load($scrollingStyle);
 
                 return new $className();
 
             case 'null':
                 // Fall through to default case
 
             default:
                 /**
                  * @see Zend_View_Exception
                  */
                 // require_once 'Zend/View/Exception.php';
 
                 throw new Zend_View_Exception('Scrolling style must be a class ' .
                     'name or object implementing Zend_Paginator_ScrollingStyle_Interface');
         }
     }
 }