<?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;
use CallbackFilterIterator;
use Iterator;
/**
* Creates a filtered iterator from another iterator. The filtering is done by
* passing a callback function to each of the elements and taking them out if
* it does not return true.
*/
class FilterIterator extends Collection
{
/**
* The callback used to filter the elements in this collection
*
* @var callable
*/
protected $_callback;
/**
* Creates a filtered iterator using the callback to determine which items are
* accepted or rejected.
*
* Each time the callback is executed it will receive the value of the element
* in the current iteration, the key of the element and the passed $items iterator
* as arguments, in that order.
*
* @param \Traversable|array $items The items to be filtered.
* @param callable $callback Callback.
*/
public function __construct($items, callable $callback)
{
if (!$items instanceof Iterator) {
$items = new Collection($items);
}
$this->_callback = $callback;
$wrapper = new CallbackFilterIterator($items, $callback);
parent::__construct($wrapper);
}
/**
* {@inheritDoc}
*
* We perform here some strictness analysis so that the
* iterator logic is bypassed entirely.
*
* @return \Iterator
*/
public function unwrap()
{
/** @var \IteratorIterator $filter */
$filter = $this->getInnerIterator();
$iterator = $filter->getInnerIterator();
if ($iterator instanceof CollectionInterface) {
$iterator = $iterator->unwrap();
}
if (get_class($iterator) !== ArrayIterator::class) {
return $filter;
}
// ArrayIterator can be traversed strictly.
// Let's do that for performance gains
$callback = $this->_callback;
$res = [];
foreach ($iterator as $k => $v) {
if ($callback($v, $k, $iterator)) {
$res[$k] = $v;
}
}
return new ArrayIterator($res);
}
}