<?php
/**
* CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
* Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
*
* Licensed under The MIT License
* For full copyright and license information, please see the LICENSE.txt
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
* @link https://cakephp.org CakePHP(tm) Project
* @since 3.0.0
* @license https://opensource.org/licenses/mit-license.php MIT License
*/
namespace Cake\Collection\Iterator;
use ArrayIterator;
use Cake\Collection\Collection;
use Cake\Collection\CollectionInterface;
/**
* Creates an iterator from another iterator that extract the requested column
* or property based on a path
*/
class ExtractIterator extends Collection
{
/**
* A callable responsible for extracting a single value for each
* item in the collection.
*
* @var callable
*/
protected $_extractor;
/**
* Creates the iterator that will return the requested property for each value
* in the collection expressed in $path
*
* ### Example:
*
* Extract the user name for all comments in the array:
*
* ```
* $items = [
* ['comment' => ['body' => 'cool', 'user' => ['name' => 'Mark']],
* ['comment' => ['body' => 'very cool', 'user' => ['name' => 'Renan']]
* ];
* $extractor = new ExtractIterator($items, 'comment.user.name'');
* ```
*
* @param array|\Traversable $items The list of values to iterate
* @param string $path a dot separated string symbolizing the path to follow
* inside the hierarchy of each value so that the column can be extracted.
*/
public function __construct($items, $path)
{
$this->_extractor = $this->_propertyExtractor($path);
parent::__construct($items);
}
/**
* Returns the column value defined in $path or null if the path could not be
* followed
*
* @return mixed
*/
public function current()
{
$extractor = $this->_extractor;
return $extractor(parent::current());
}
/**
* {@inheritDoc}
*
* We perform here some strictness analysis so that the
* iterator logic is bypassed entirely.
*
* @return \Iterator
*/
public function unwrap()
{
$iterator = $this->getInnerIterator();
if ($iterator instanceof CollectionInterface) {
$iterator = $iterator->unwrap();
}
if (get_class($iterator) !== ArrayIterator::class) {
return $this;
}
// ArrayIterator can be traversed strictly.
// Let's do that for performance gains
$callback = $this->_extractor;
$res = [];
/** @var \ArrayObject $iterator */
foreach ($iterator->getArrayCopy() as $k => $v) {
$res[$k] = $callback($v);
}
return new ArrayIterator($res);
}
}