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    The ParentIterator class

    (PHP 5 >= 5.1.0, PHP 7, PHP 8)

    Introduction

    This extended FilterIterator allows a recursive iteration using RecursiveIteratorIterator that only shows those elements which have children.

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    User Contributed Notes 2 notes

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    dn dot permyakov at gmail dot com
    5 years ago
    Easy example for understanding:
    <?php

    $iterator     = new ParentIterator(
    new     RecursiveArrayIterator(
    array(array(    1, 2, 3), 'A', 'B', 'C')
    )
    );

    foreach (    $iterator as $recursive) {
    foreach (    $recursive as $value) {
    echo     $value . PHP_EOL;
    }
    }
    ?>

    1
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    3
    up
    3
    Anonymous
    12 years ago
    ParentIterator is just a RecursiveFilterIterator whos accept() method calls the RecursiveFilterIterator->hasChildren() method to filter itself.

    Basically, it filters out leaf nodes. For example

    This would yield all files and directories
    <?php
    $rdi     = new RecursiveDirectoryIterator(__DIR__);
    $iter = new RecursiveIteratorIterator($rdi, RecursiveIteratorIterator::CHILD_FIRST);
    ?>

    wrapping that in a ParentIterator would filter it down to just directories
    <?php
    $rdi     = new RecursiveDirectoryIterator(__DIR__);
    $iter = new RecursiveIteratorIterator($rdi, RecursiveIteratorIterator::CHILD_FIRST);
    $dirsOnly = new ParentIterator($iter);
    ?>
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