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