对RecursiveArrayIterator进行排序

Question

I have the following code:

$itemA = array(
        'token' => "SOME_TOKEN",
        'default' => "DEFAULT A",
        'order' => 5
);
$itemB = array(
        'token' => "SOME__OTHER_TOKEN",
        'default' => "DEFAULT B",
        'order' => 2
);
$collection = new \RecursiveArrayIterator(array($itemA, $itemB));
$collection->uasort(function( $a, $b ) {
        if ($a['order'] === $b['order']) {
                return 0;
        }
        return ($a['order'] < $b['order']) ? -1 : 1;
});

Which was supposed to sort the $collection internal array. In fact, it does, because when I var_dump($collection) - I can see that $itemB is the first (as it has lower order).

BUT - when I start iterating items from $collection, I am still getting $itemA as the first element.

Unfortunately, documentation doesn't have any mentions of the issue, which is why I would like to know if this is a bug or I missed something?

UPDATE

The iteration code:

while ($collection->valid())
{
    $current = $collection->current(); // current is already wrong :(
    ... do stuff ...
    $collection->next();
}

My php version is 5.3.10, in case this is relevant. Gist with a failing unit test.

Answer 1

It looks like uasort affects the internal current pointer of the iterator, so you need $collection->rewind() before the loop. Better yet, instead of while(valid), use foreach, which automatically rewinds it for you:

$collection = new \RecursiveArrayIterator(...);
$collection->uasort(function( $a, $b ) {
    return $a['order'] - $b['order'];
});

foreach($collection as $item)
    print_r($item); // all fine