interface/modules/zend_modules/library/Zend/View/Resolver/AggregateResolver.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\View\Resolver;
  11
  12 use Countable;
  13 use IteratorAggregate;
  14 use Zend\Stdlib\PriorityQueue;
  15 use Zend\View\Renderer\RendererInterface as Renderer;
  16 use Zend\View\Resolver\ResolverInterface as Resolver;
  17
  18 class AggregateResolver implements Countable, IteratorAggregate, ResolverInterface
  19 {
  20     const FAILURE_NO_RESOLVERS = 'AggregateResolver_Failure_No_Resolvers';
  21     const FAILURE_NOT_FOUND    = 'AggregateResolver_Failure_Not_Found';
  22
  23     /**
  24      * Last lookup failure
  25      * @var false|string
  26      */
  27     protected $lastLookupFailure = false;
  28
  29     /**
  30      * @var Resolver
  31      */
  32     protected $lastSuccessfulResolver;
  33
  34     /**
  35      * @var PriorityQueue
  36      */
  37     protected $queue;
  38
  39     /**
  40      * Constructor
  41      *
  42      * Instantiate the internal priority queue
  43      *
  44      */
  45     public function __construct()
  46     {
  47         $this->queue = new PriorityQueue();
  48     }
  49
  50     /**
  51      * Return count of attached resolvers
  52      *
  53      * @return int
  54      */
  55     public function count()
  56     {
  57         return $this->queue->count();
  58     }
  59
  60     /**
  61      * IteratorAggregate: return internal iterator
  62      *
  63      * @return PriorityQueue
  64      */
  65     public function getIterator()
  66     {
  67         return $this->queue;
  68     }
  69
  70     /**
  71      * Attach a resolver
  72      *
  73      * @param  Resolver $resolver
  74      * @param  int $priority
  75      * @return AggregateResolver
  76      */
  77     public function attach(Resolver $resolver, $priority = 1)
  78     {
  79         $this->queue->insert($resolver, $priority);
  80         return $this;
  81     }
  82
  83     /**
  84      * Resolve a template/pattern name to a resource the renderer can consume
  85      *
  86      * @param  string $name
  87      * @param  null|Renderer $renderer
  88      * @return false|string
  89      */
  90     public function resolve($name, Renderer $renderer = null)
  91     {
  92         $this->lastLookupFailure      = false;
  93         $this->lastSuccessfulResolver = null;
  94
  95         if (0 === count($this->queue)) {
  96             $this->lastLookupFailure = static::FAILURE_NO_RESOLVERS;
  97             return false;
  98         }
  99
 100         foreach ($this->queue as $resolver) {
 101             $resource = $resolver->resolve($name, $renderer);
 102             if (!$resource) {
 103                 // No resource found; try next resolver
 104                 continue;
 105             }
 106
 107             // Resource found; return it
 108             $this->lastSuccessfulResolver = $resolver;
 109             return $resource;
 110         }
 111
 112         $this->lastLookupFailure = static::FAILURE_NOT_FOUND;
 113         return false;
 114     }
 115
 116     /**
 117      * Return the last successful resolver, if any
 118      *
 119      * @return Resolver
 120      */
 121     public function getLastSuccessfulResolver()
 122     {
 123         return $this->lastSuccessfulResolver;
 124     }
 125
 126     /**
 127      * Get last lookup failure
 128      *
 129      * @return false|string
 130      */
 131     public function getLastLookupFailure()
 132     {
 133         return $this->lastLookupFailure;
 134     }
 135 }