ConFoo 2025

A classe MultipleIterator

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

Introdução

Um Iterador que itera sequencialmente sobre todos os iteradores anexados

Resumo da classe

class MultipleIterator implements Iterator {
/* Constantes */
public const int MIT_NEED_ANY;
public const int MIT_NEED_ALL;
public const int MIT_KEYS_NUMERIC;
public const int MIT_KEYS_ASSOC;
/* Métodos */
public __construct(int $flags = MultipleIterator::MIT_NEED_ALL | MultipleIterator::MIT_KEYS_NUMERIC)
public attachIterator(Iterator $iterator, string|int|null $info = null): void
public containsIterator(Iterator $iterator): bool
public current(): array
public detachIterator(Iterator $iterator): void
public getFlags(): int
public key(): array
public next(): void
public rewind(): void
public setFlags(int $flags): void
public valid(): bool
}

Constantes predefinidas

MultipleIterator::MIT_NEED_ANY

Não requer que todos os subiteradores sejam válidos na iteração.

MultipleIterator::MIT_NEED_ALL

Requer que todos os subiteradores sejam válidos na iteração.

MultipleIterator::MIT_KEYS_NUMERIC

As chaves são criadas a partir da posição dos subiteradores.

MultipleIterator::MIT_KEYS_ASSOC

As chaves são criadas a partir das informações associadas aos subiteradores.

Índice

adicione uma nota

Notas Enviadas por Usuários (em inglês) 1 note

up
37
sven at rtbg dot de
9 years ago
This iterator has a misleading name and description - it actually acts as a parallel iterator: You attach one or more iterators with a key, integer or NULL, and when you iterate over the MultipleIterator, as the result for current() you get ALL results from all attached iterators as an array (under the key or integer you attached it with), and the same is true for the key() call.

valid() will be valid if any or all iterators are valid, depending on the setting of the $flags - with ANY, you can iterate over a set of iterators with some of them ending before others, and get NULL results from these iterators until the last iterator is at it's end. With ALL, iteration stops when the first iterator stops delivering results.

next() and rewind() will be called on all attached iterators in every case.

<?php

$it1
= new ArrayIterator(array(1,2,3));
$it2 = new ArrayIterator(array(4,5,6));

$multipleIterator = new MultipleIterator(MultipleIterator::MIT_NEED_ALL|MultipleIterator::MIT_KEYS_ASSOC);

$multipleIterator->attachIterator($it1, 1);
$multipleIterator->attachIterator($it2, 'second');

foreach (
$multipleIterator as $key => $value) {
echo
"Key\n"; var_dump($key);
echo
"Value\n"; var_dump($value);
echo
"---next---\n";
}
?>

Result with PHP 5.5.0 and up:

Key
array(2) {
[1]=>
int(0)
["second"]=>
int(0)
}
Value
array(2) {
[1]=>
int(1)
["second"]=>
int(4)
}
---next---
Key
array(2) {
[1]=>
int(1)
["second"]=>
int(1)
}
Value
array(2) {
[1]=>
int(2)
["second"]=>
int(5)
}
---next---
Key
array(2) {
[1]=>
int(2)
["second"]=>
int(2)
}
Value
array(2) {
[1]=>
int(3)
["second"]=>
int(6)
}
---next---

Note that PHP 5.4 and 5.3 do not support accessing the key() values in foreach loops because they expect them to not be an array - doing so will cause "Warning: Illegal type returned from MultipleIterator::key()" and the result of (int)0 as the key for all iterations.

Without the MultipleIterator::MIT_KEYS_ASSOC flag, the MultipleIterator will create numeric indices based on the order of attachment.
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