1: <?php
 2: /**
 3:  * CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
 4:  * Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
 5:  *
 6:  * Licensed under The MIT License
 7:  * For full copyright and license information, please see the LICENSE.txt
 8:  * Redistributions of files must retain the above copyright notice.
 9:  *
10:  * @copyright     Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
11:  * @link          https://cakephp.org CakePHP(tm) Project
12:  * @since         3.0.0
13:  * @license       https://opensource.org/licenses/mit-license.php MIT License
14:  */
15: namespace Cake\Collection\Iterator;
16: 
17: use Cake\Collection\Collection;
18: use RecursiveIterator;
19: use Traversable;
20: 
21: /**
22:  * A type of collection that is aware of nested items and exposes methods to
23:  * check or retrieve them
24:  */
25: class NestIterator extends Collection implements RecursiveIterator
26: {
27:     /**
28:      * The name of the property that contains the nested items for each element
29:      *
30:      * @var string|callable
31:      */
32:     protected $_nestKey;
33: 
34:     /**
35:      * Constructor
36:      *
37:      * @param array|\Traversable $items Collection items.
38:      * @param string|callable $nestKey the property that contains the nested items
39:      * If a callable is passed, it should return the childrens for the passed item
40:      */
41:     public function __construct($items, $nestKey)
42:     {
43:         parent::__construct($items);
44:         $this->_nestKey = $nestKey;
45:     }
46: 
47:     /**
48:      * Returns a traversable containing the children for the current item
49:      *
50:      * @return \RecursiveIterator
51:      */
52:     public function getChildren()
53:     {
54:         $property = $this->_propertyExtractor($this->_nestKey);
55: 
56:         return new static($property($this->current()), $this->_nestKey);
57:     }
58: 
59:     /**
60:      * Returns true if there is an array or a traversable object stored under the
61:      * configured nestKey for the current item
62:      *
63:      * @return bool
64:      */
65:     public function hasChildren()
66:     {
67:         $property = $this->_propertyExtractor($this->_nestKey);
68:         $children = $property($this->current());
69: 
70:         if (is_array($children)) {
71:             return !empty($children);
72:         }
73: 
74:         return $children instanceof Traversable;
75:     }
76: }
77: