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 RecursiveIterator;
 19: use RecursiveIteratorIterator;
 20: 
 21: /**
 22:  * A Recursive iterator used to flatten nested structures and also exposes
 23:  * all Collection methods
 24:  */
 25: class TreeIterator extends RecursiveIteratorIterator
 26: {
 27:     use CollectionTrait;
 28: 
 29:     /**
 30:      * The iteration mode
 31:      *
 32:      * @var int
 33:      */
 34:     protected $_mode;
 35: 
 36:     /**
 37:      * Constructor
 38:      *
 39:      * @param \RecursiveIterator $items The iterator to flatten.
 40:      * @param int $mode Iterator mode.
 41:      * @param int $flags Iterator flags.
 42:      */
 43:     public function __construct(RecursiveIterator $items, $mode = RecursiveIteratorIterator::SELF_FIRST, $flags = 0)
 44:     {
 45:         parent::__construct($items, $mode, $flags);
 46:         $this->_mode = $mode;
 47:     }
 48: 
 49:     /**
 50:      * Returns another iterator which will return the values ready to be displayed
 51:      * to a user. It does so by extracting one property from each of the elements
 52:      * and prefixing it with a spacer so that the relative position in the tree
 53:      * can be visualized.
 54:      *
 55:      * Both $valuePath and $keyPath can be a string with a property name to extract
 56:      * or a dot separated path of properties that should be followed to get the last
 57:      * one in the path.
 58:      *
 59:      * Alternatively, $valuePath and $keyPath can be callable functions. They will get
 60:      * the current element as first parameter, the current iteration key as second
 61:      * parameter, and the iterator instance as third argument.
 62:      *
 63:      * ### Example
 64:      *
 65:      * ```
 66:      *  $printer = (new Collection($treeStructure))->listNested()->printer('name');
 67:      * ```
 68:      *
 69:      * Using a closure:
 70:      *
 71:      * ```
 72:      *  $printer = (new Collection($treeStructure))
 73:      *      ->listNested()
 74:      *      ->printer(function ($item, $key, $iterator) {
 75:      *          return $item->name;
 76:      *      });
 77:      * ```
 78:      *
 79:      * @param string|callable $valuePath The property to extract or a callable to return
 80:      * the display value
 81:      * @param string|callable|null $keyPath The property to use as iteration key or a
 82:      * callable returning the key value.
 83:      * @param string $spacer The string to use for prefixing the values according to
 84:      * their depth in the tree
 85:      * @return \Cake\Collection\Iterator\TreePrinter
 86:      */
 87:     public function printer($valuePath, $keyPath = null, $spacer = '__')
 88:     {
 89:         if (!$keyPath) {
 90:             $counter = 0;
 91:             $keyPath = function () use (&$counter) {
 92:                 return $counter++;
 93:             };
 94:         }
 95: 
 96:         return new TreePrinter(
 97:             $this->getInnerIterator(),
 98:             $valuePath,
 99:             $keyPath,
100:             $spacer,
101:             $this->_mode
102:         );
103:     }
104: }
105: