1 <?php

     2 /**

     3  * @category   Zend

     4  * @package    Zend_Cloud

     5  * @subpackage Infrastructure

     6  * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)

     7  * @license    http://framework.zend.com/license/new-bsd     New BSD License

     8  */

     9 

    10 require_once 'Zend/Cloud/Infrastructure/Instance.php';

    11 

    12 /**

    13  * List of instances

    14  *

    15  * @package    Zend_Cloud

    16  * @subpackage Infrastructure

    17  * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)

    18  * @license    http://framework.zend.com/license/new-bsd     New BSD License

    19  */

    20 class Zend_Cloud_Infrastructure_InstanceList implements Countable, Iterator, ArrayAccess

    21 {

    22     /**

    23      * @var array Array of Zend_Cloud_Infrastructure_Instance

    24      */

    25     protected $instances = array();

    26 

    27     /**

    28      * @var int Iterator key

    29      */

    30     protected $iteratorKey = 0;

    31 

    32     /**

    33      * @var Zend_Cloud_Infrastructure_Adapter

    34      */

    35     protected $adapter;

    36 

    37     /**

    38      * Constructor

    39      *

    40      * @param  Adapter $adapter

    41      * @param  array $instances

    42      * @return void

    43      */

    44     public function __construct($adapter, array $instances = null)

    45     {

    46         if (!($adapter instanceof Zend_Cloud_Infrastructure_Adapter)) {

    47             require_once 'Zend/Cloud/Infrastructure/Exception.php';

    48             throw new Zend_Cloud_Infrastructure_Exception('You must pass a Zend_Cloud_Infrastructure_Adapter');

    49         }

    50         if (empty($instances)) {

    51             require_once 'Zend/Cloud/Infrastructure/Exception.php';

    52             throw new Zend_Cloud_Infrastructure_Exception('You must pass an array of Instances');

    53         }

    54 

    55         $this->adapter = $adapter;

    56         $this->constructFromArray($instances);

    57     }

    58 

    59     /**

    60      * Transforms the Array to array of Instances

    61      *

    62      * @param  array $list

    63      * @return void

    64      */

    65     protected function constructFromArray(array $list)

    66     {

    67         foreach ($list as $instance) {

    68             $this->addInstance(new Zend_Cloud_Infrastructure_Instance($this->adapter,$instance));

    69         }

    70     }

    71 

    72     /**

    73      * Add an instance

    74      *

    75      * @param  Instance

    76      * @return InstanceList

    77      */

    78     protected function addInstance(Zend_Cloud_Infrastructure_Instance $instance)

    79     {

    80         $this->instances[] = $instance;

    81         return $this;

    82     }

    83 

    84     /**

    85      * Return number of instances

    86      *

    87      * Implement Countable::count()

    88      *

    89      * @return int

    90      */

    91     public function count()

    92     {

    93         return count($this->instances);

    94     }

    95 

    96     /**

    97      * Return the current element

    98      *

    99      * Implement Iterator::current()

   100      *

   101      * @return Instance

   102      */

   103     public function current()

   104     {

   105         return $this->instances[$this->iteratorKey];

   106     }

   107 

   108     /**

   109      * Return the key of the current element

   110      *

   111      * Implement Iterator::key()

   112      *

   113      * @return int

   114      */

   115     public function key()

   116     {

   117         return $this->iteratorKey;

   118     }

   119 

   120     /**

   121      * Move forward to next element

   122      *

   123      * Implement Iterator::next()

   124      *

   125      * @return void

   126      */

   127     public function next()

   128     {

   129         $this->iteratorKey++;

   130     }

   131 

   132     /**

   133      * Rewind the Iterator to the first element

   134      *

   135      * Implement Iterator::rewind()

   136      *

   137      * @return void

   138      */

   139     public function rewind()

   140     {

   141         $this->iteratorKey = 0;

   142     }

   143 

   144     /**

   145      * Check if there is a current element after calls to rewind() or next()

   146      *

   147      * Implement Iterator::valid()

   148      *

   149      * @return bool

   150      */

   151     public function valid()

   152     {

   153         $numItems = $this->count();

   154         if ($numItems > 0 && $this->iteratorKey < $numItems) {

   155             return true;

   156         }

   157         return false;

   158     }

   159 

   160     /**

   161      * Whether the offset exists

   162      *

   163      * Implement ArrayAccess::offsetExists()

   164      *

   165      * @param  int $offset

   166      * @return bool

   167      */

   168     public function offsetExists($offset)

   169     {

   170         return ($offset < $this->count());

   171     }

   172 

   173     /**

   174      * Return value at given offset

   175      *

   176      * Implement ArrayAccess::offsetGet()

   177      *

   178      * @param  int $offset

   179      * @return Instance

   180      * @throws Zend_Cloud_Infrastructure_Exception

   181      */

   182     public function offsetGet($offset)

   183     {

   184         if (!$this->offsetExists($offset)) {

   185             require_once 'Zend/Cloud/Infrastructure/Exception.php';

   186             throw new Zend_Cloud_Infrastructure_Exception('Illegal index');

   187         }

   188         return $this->instances[$offset];

   189     }

   190 

   191     /**

   192      * Throws exception because all values are read-only

   193      *

   194      * Implement ArrayAccess::offsetSet()

   195      *

   196      * @param   int     $offset

   197      * @param   string  $value

   198      * @throws  Zend_Cloud_Infrastructure_Exception

   199      */

   200     public function offsetSet($offset, $value)

   201     {

   202         require_once 'Zend/Cloud/Infrastructure/Exception.php';

   203         throw new Zend_Cloud_Infrastructure_Exception('You are trying to set read-only property');

   204     }

   205 

   206     /**

   207      * Throws exception because all values are read-only

   208      *

   209      * Implement ArrayAccess::offsetUnset()

   210      *

   211      * @param   int     $offset

   212      * @throws  Zend_Cloud_Infrastructure_Exception

   213      */

   214     public function offsetUnset($offset)

   215     {

   216         require_once 'Zend/Cloud/Infrastructure/Exception.php';

   217         throw new Zend_Cloud_Infrastructure_Exception('You are trying to unset read-only property');

   218     }

   219 }