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\CollectionTrait;
 18: use RecursiveIteratorIterator;
 19: 
 20: /**
 21:  * Iterator for flattening elements in a tree structure while adding some
 22:  * visual markers for their relative position in the tree
 23:  */
 24: class TreePrinter extends RecursiveIteratorIterator
 25: {
 26: 
 27:     use CollectionTrait;
 28: 
 29:     /**
 30:      * A callable to generate the iteration key
 31:      *
 32:      * @var callable
 33:      */
 34:     protected $_key;
 35: 
 36:     /**
 37:      * A callable to extract the display value
 38:      *
 39:      * @var callable
 40:      */
 41:     protected $_value;
 42: 
 43:     /**
 44:      * Cached value for the current iteration element
 45:      *
 46:      * @var mixed
 47:      */
 48:     protected $_current;
 49: 
 50:     /**
 51:      * The string to use for prefixing the values according to their depth in the tree.
 52:      *
 53:      * @var string
 54:      */
 55:     protected $_spacer;
 56: 
 57:     /**
 58:      * Constructor
 59:      *
 60:      * @param \RecursiveIterator $items The iterator to flatten.
 61:      * @param string|callable $valuePath The property to extract or a callable to return
 62:      * the display value.
 63:      * @param string|callable $keyPath The property to use as iteration key or a
 64:      * callable returning the key value.
 65:      * @param string $spacer The string to use for prefixing the values according to
 66:      * their depth in the tree.
 67:      * @param int $mode Iterator mode.
 68:      */
 69:     public function __construct($items, $valuePath, $keyPath, $spacer, $mode = RecursiveIteratorIterator::SELF_FIRST)
 70:     {
 71:         parent::__construct($items, $mode);
 72:         $this->_value = $this->_propertyExtractor($valuePath);
 73:         $this->_key = $this->_propertyExtractor($keyPath);
 74:         $this->_spacer = $spacer;
 75:     }
 76: 
 77:     /**
 78:      * Returns the current iteration key
 79:      *
 80:      * @return mixed
 81:      */
 82:     public function key()
 83:     {
 84:         $extractor = $this->_key;
 85: 
 86:         return $extractor($this->_fetchCurrent(), parent::key(), $this);
 87:     }
 88: 
 89:     /**
 90:      * Returns the current iteration value
 91:      *
 92:      * @return string
 93:      */
 94:     public function current()
 95:     {
 96:         $extractor = $this->_value;
 97:         $current = $this->_fetchCurrent();
 98:         $spacer = str_repeat($this->_spacer, $this->getDepth());
 99: 
100:         return $spacer . $extractor($current, parent::key(), $this);
101:     }
102: 
103:     /**
104:      * Advances the cursor one position
105:      *
106:      * @return void
107:      */
108:     public function next()
109:     {
110:         parent::next();
111:         $this->_current = null;
112:     }
113: 
114:     /**
115:      * Returns the current iteration element and caches its value
116:      *
117:      * @return mixed
118:      */
119:     protected function _fetchCurrent()
120:     {
121:         if ($this->_current !== null) {
122:             return $this->_current;
123:         }
124: 
125:         return $this->_current = parent::current();
126:     }
127: }
128: