interface/modules/zend_modules/library/Zend/EventManager/FilterChain.php

   1 <?php
   2 /**
   3  * Zend Framework (http://framework.zend.com/)
   4  *
   5  * @link      http://github.com/zendframework/zf2 for the canonical source repository
   6  * @copyright Copyright (c) 2005-2013 Zend Technologies USA Inc. (http://www.zend.com)
   7  * @license   http://framework.zend.com/license/new-bsd New BSD License
   8  */
   9
  10 namespace Zend\EventManager;
  11
  12 use Zend\Stdlib\CallbackHandler;
  13
  14 /**
  15  * FilterChain: intercepting filter manager
  16  */
  17 class FilterChain implements Filter\FilterInterface
  18 {
  19     /**
  20      * @var Filter\FilterIterator All filters
  21      */
  22     protected $filters;
  23
  24     /**
  25      * Constructor
  26      *
  27      * Initializes Filter\FilterIterator in which filters will be aggregated
  28      */
  29     public function __construct()
  30     {
  31         $this->filters = new Filter\FilterIterator();
  32     }
  33
  34     /**
  35      * Apply the filters
  36      *
  37      * Begins iteration of the filters.
  38      *
  39      * @param  mixed $context Object under observation
  40      * @param  mixed $argv Associative array of arguments
  41      * @return mixed
  42      */
  43     public function run($context, array $argv = array())
  44     {
  45         $chain = clone $this->getFilters();
  46
  47         if ($chain->isEmpty()) {
  48             return;
  49         }
  50
  51         $next = $chain->extract();
  52         if (!$next instanceof CallbackHandler) {
  53             return;
  54         }
  55
  56         return call_user_func($next->getCallback(), $context, $argv, $chain);
  57     }
  58
  59     /**
  60      * Connect a filter to the chain
  61      *
  62      * @param  callable $callback PHP Callback
  63      * @param  int $priority Priority in the queue at which to execute; defaults to 1 (higher numbers == higher priority)
  64      * @return CallbackHandler (to allow later unsubscribe)
  65      * @throws Exception\InvalidCallbackException
  66      */
  67     public function attach($callback, $priority = 1)
  68     {
  69         if (empty($callback)) {
  70             throw new Exception\InvalidCallbackException('No callback provided');
  71         }
  72         $filter = new CallbackHandler($callback, array('priority' => $priority));
  73         $this->filters->insert($filter, $priority);
  74         return $filter;
  75     }
  76
  77     /**
  78      * Detach a filter from the chain
  79      *
  80      * @param  CallbackHandler $filter
  81      * @return bool Returns true if filter found and unsubscribed; returns false otherwise
  82      */
  83     public function detach(CallbackHandler $filter)
  84     {
  85         return $this->filters->remove($filter);
  86     }
  87
  88     /**
  89      * Retrieve all filters
  90      *
  91      * @return Filter\FilterIterator
  92      */
  93     public function getFilters()
  94     {
  95         return $this->filters;
  96     }
  97
  98     /**
  99      * Clear all filters
 100      *
 101      * @return void
 102      */
 103     public function clearFilters()
 104     {
 105         $this->filters = new Filter\FilterIterator();
 106     }
 107
 108     /**
 109      * Return current responses
 110      *
 111      * Only available while the chain is still being iterated. Returns the
 112      * current ResponseCollection.
 113      *
 114      * @return null|ResponseCollection
 115      */
 116     public function getResponses()
 117     {
 118         return null;
 119     }
 120 }