<?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 will verify a condition on each
* step. If the condition evaluates to false, the iterator will not yield more
* results.
*
* @internal
* @see \Cake\Collection\Collection::stopWhen()
*/
class StoppableIterator extends Collection
{
/**
* The condition to evaluate for each item of the collection
*
* @var callable
*/
protected $_condition;
/**
* A reference to the internal iterator this object is wrapping.
*
* @var \Iterator
*/
protected $_innerIterator;
/**
* Creates an iterator that can be stopped based on a condition provided by a callback.
*
* Each time the condition 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 array|\Traversable $items The list of values to iterate
* @param callable $condition A function that will be called for each item in
* the collection, if the result evaluates to false, no more items will be
* yielded from this iterator.
*/
public function __construct($items, callable $condition)
{
$this->_condition = $condition;
parent::__construct($items);
$this->_innerIterator = $this->getInnerIterator();
}
/**
* Evaluates the condition and returns its result, this controls
* whether or not more results will be yielded.
*
* @return bool
*/
public function valid()
{
if (!parent::valid()) {
return false;
}
$current = $this->current();
$key = $this->key();
$condition = $this->_condition;
return !$condition($current, $key, $this->_innerIterator);
}
/**
* {@inheritDoc}
*
* We perform here some strictness analysis so that the
* iterator logic is bypassed entirely.
*
* @return \Iterator
*/
public function unwrap()
{
$iterator = $this->_innerIterator;
if ($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->_condition;
$res = [];
foreach ($iterator as $k => $v) {
if ($callback($v, $k, $iterator)) {
break;
}
$res[$k] = $v;
}
return new ArrayIterator($res);
}
}