betterCode() PHP 2025

    Класс RecursiveIteratorIterator

    (PHP 5, PHP 7, PHP 8)

    Введение

    Может быть использован для перебора рекурсивных итераторов.

    Обзор класса

    class RecursiveIteratorIterator implements OuterIterator {
    /* Константы */
    public const int LEAVES_ONLY;
    public const int SELF_FIRST;
    public const int CHILD_FIRST;
    public const int CATCH_GET_CHILD;
    /* Методы */
    public __construct(Traversable $iterator, int $mode = RecursiveIteratorIterator::LEAVES_ONLY, int $flags = 0)
    public beginChildren(): void
    public beginIteration(): void
    public callGetChildren(): ?RecursiveIterator
    public callHasChildren(): bool
    public current(): mixed
    public endChildren(): void
    public endIteration(): void
    public getDepth(): int
    public getInnerIterator(): RecursiveIterator
    public getMaxDepth(): int|false
    public getSubIterator(?int $level = null): ?RecursiveIterator
    public key(): mixed
    public next(): void
    public nextElement(): void
    public rewind(): void
    public setMaxDepth(int $maxDepth = -1): void
    public valid(): bool
    }

    Содержание

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    Примечания пользователей 7 notes

    up
    24
    Anonymous
    8 years ago
    A very useful use case for RecusiveIteratorIterator in combination with RecursiveArrayIterator is to replace array values on a multidimensional array at any level deep.

    Usually, array_walk_recursive would be used to replace values deep within arrays, but unfortunately this only works when there is a standard key value pair - in other words, array_walk_recursive ONLY VISITS LEAF NODES, NOT arrays.

    So to get around this, the iterators can be used in this way:

    <?php
    $array     = [
    'test' => 'value',
    'level_one' => [
    'level_two' => [
    'level_three' => [
    'replace_this_array' => [
    'special_key' => 'replacement_value',
    'key_one' => 'testing',
    'key_two' => 'value',
    'four' => 'another value'
    ]
    ],
    'ordinary_key' => 'value'
    ]
    ]
    ];

    $arrayIterator = new \RecursiveArrayIterator($array);
    $recursiveIterator = new \RecursiveIteratorIterator($arrayIterator, \RecursiveIteratorIterator::SELF_FIRST);

    foreach (    $recursiveIterator as $key => $value) {
    if (    is_array($value) && array_key_exists('special_key', $value)) {
    // Here we replace ALL keys with the same value from 'special_key'
    $replaced = array_fill(0, count($value), $value['special_key']);
    $value = array_combine(array_keys($value), $replaced);
    // set a new key
    $value['new_key'] = 'new value';

    // Get the current depth and traverse back up the tree, saving the modifications
    $currentDepth = $recursiveIterator->getDepth();
    for (    $subDepth = $currentDepth; $subDepth >= 0; $subDepth--) {
    // Get the current level iterator
    $subIterator = $recursiveIterator->getSubIterator($subDepth);
    // If we are on the level we want to change, use the replacements ($value) other wise set the key to the parent iterators value
    $subIterator->offsetSet($subIterator->key(), ($subDepth === $currentDepth ? $value : $recursiveIterator->getSubIterator(($subDepth+1))->getArrayCopy()));
    }
    }
    }
    return     $recursiveIterator->getArrayCopy();
    // return:
    $array = [
    'test' => 'value',
    'level_one' => [
    'level_two' => [
    'level_three' => [
    'replace_this_array' => [
    'special_key' => 'replacement_value',
    'key_one' => 'replacement_value',
    'key_two' => 'replacement_value',
    'four' => 'replacement_value',
    'new_key' => 'new value'
    ]
    ],
    'ordinary_key' => 'value'
    ]
    ]
    ];
    ?>

    The key is in traversing back up the tree to save the changes at that level - simply calling $recursiveIterator->offsetSet(); will only set a key on the root array.
    up
    11
    Adil Baig @ AIdezigns
    14 years ago
    A very important thing to note about \RecursiveIteratorIterator is that it returns a flattened array when used with the iterator_to_array function. Ex:

    <?php
    $arr     = array('Zero', 'name'=>'Adil', 'address' => array( 'city'=>'Dubai', 'tel' => array('int' => 971, 'tel'=>12345487)), '' => 'nothing');

    $iterator = new \RecursiveIteratorIterator(new \RecursiveArrayIterator($arr));
    var_dump(iterator_to_array($iterator,true));
    ?>

    This code will return :

    array(6) {
    [0]=>
    string(4) "Zero"
    ["name"]=>
    string(4) "Adil"
    ["city"]=>
    string(5) "Dubai"
    ["int"]=>
    int(91)
    ["tel"]=>
    int(12345487)
    [""]=>
    string(7) "nothing"
    }

    To get the non-flattened proper array use the getArrayCopy() method, like so :

    $iterator->getArrayCopy()

    This will return

    array(4) {
    [0]=>
    string(4) "Zero"
    ["name"]=>
    string(4) "Adil"
    ["address"]=>
    array(2) {
    ["city"]=>
    string(5) "Dubai"
    ["tel"]=>
    array(2) {
    ["int"]=>
    int(91)
    ["tel"]=>
    int(12345487)
    }
    }
    [""]=>
    string(7) "nothing"
    }
    up
    11
    aidan at php dot net
    15 years ago
    This example demonstrates using the getDepth() method with a RecursiveArrayIterator.

    <?php
    $tree     = array();
    $tree[1][2][3] = 'lemon';
    $tree[1][4] = 'melon';
    $tree[2][3] = 'orange';
    $tree[2][5] = 'grape';
    $tree[3] = 'pineapple';

    print_r($tree);

    $arrayiter = new RecursiveArrayIterator($tree);
    $iteriter = new RecursiveIteratorIterator($arrayiter);

    foreach (    $iteriter as $key => $value) {
    $d = $iteriter->getDepth();
    echo     "depth=$d k=$key v=$value\n";
    }
    ?>

    The output of this would be:

    Array
    (
    [1] => Array
    (
    [2] => Array
    (
    [3] => lemon
    )

    [4] => melon
    )

    [2] => Array
    (
    [3] => orange
    [5] => grape
    )

    [3] => pineapple
    )

    depth=2 k=3 v=lemon
    depth=1 k=4 v=melon
    depth=1 k=3 v=orange
    depth=1 k=5 v=grape
    depth=0 k=3 v=pineapple
    up
    14
    Michiel Brandenburg
    16 years ago
    You can use this to quickly find all the files (recursively) in a certain directory. This beats maintaining a stack yourself.
    <?php
    $directory     = "/tmp/";
    $fileSPLObjects = new RecursiveIteratorIterator(
    new     RecursiveDirectoryIterator($directory),
    RecursiveIteratorIterator::CHILD_FIRST
    );
    try {
    foreach(     $fileSPLObjects as $fullFileName => $fileSPLObject ) {
    print     $fullFileName . " " . $fileSPLObject->getFilename() . "\n";
    }
    }
    catch (    UnexpectedValueException $e) {
    printf("Directory [%s] contained a directory we can not recurse into", $directory);
    }
    ?>
    Note: if there is a directory contained within the directory you are searching in that you have no access to read an UnexpectedValueException will be thrown (leaving you with an empty list).
    Note: objects returned are SPLFileObjects
    up
    8
    gerry at king-foo dot be
    11 years ago
    Carefull when using iterator_to_array(). Because it flattens down your subiterators, elements with the same keys will overwrite eachother.

    For example:

    <?php

    $iterator     = new RecursiveIteratorIterator(
    new     RecursiveArrayIterator([
    [    'foo', 'bar'],
    [    'baz', 'qux']
    ])
    );

    foreach (    $iterator as $element) {
    echo     $element;
    }

    ?>

    This will output all 4 elements as expected:

    string(3) "foo"
    string(3) "bar"
    string(3) "baz"
    string(3) "qux"

    While doing:

    <?php

    var_dump    (iterator_to_array($iterator));

    ?>

    will output an array with only the last 2 elements:

    array(2) {
    [0]=>
    string(3) "baz"
    [1]=>
    string(3) "qux"
    }
    up
    6
    Tom
    14 years ago
    This class operates on a tree of elements, which is build by nesting recursive iterators into one another.

    Thus you might say it is an iterator over iterators. While traversing those, the class pushes the iterators on a stack while traversing down to a leaf and removes them from the stack while going back up.
    up
    3
    fengdingbo at gmail dot com
    12 years ago
    if you want traversal directory。
    <?php
    foreach (new RecursiveIteratorIterator(new RecursiveDirectoryIterator("./")) as $key=>$val)
    {
    echo     $key,"=>",$val,"\n";
    }
    ?>
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