The RecursiveCallbackFilterIterator class

    (PHP 5 >= 5.4.0, PHP 7, PHP 8)

    Introduction

    Examples

    The callback should accept up to three arguments: the current item, the current key and the iterator, respectively.

    Example #1 Available callback arguments

    <?php

    /**
    * Callback for RecursiveCallbackFilterIterator
    *
    * @param $current Current item's value
    * @param $key Current item's key
    * @param $iterator Iterator being filtered
    * @return boolean TRUE to accept the current item, FALSE otherwise
    */
    function my_callback($current, $key, $iterator) {
    // Your filtering code here
    }

    ?>

    Filtering a recursive iterator generally involves two conditions. The first is that, to allow recursion, the callback function should return true if the current iterator item has children. The second is the normal filter condition, such as a file size or extension check as in the example below.

    Example #2 Recursive callback basic example

    <?php

    $dir     = new RecursiveDirectoryIterator(__DIR__);

    // Filter large files ( > 100MB)
    $files = new RecursiveCallbackFilterIterator($dir, function ($current, $key, $iterator) {
    // Allow recursion
    if ($iterator->hasChildren()) {
    return     TRUE;
    }
    // Check for large file
    if ($current->isFile() && $current->getSize() > 104857600) {
    return     TRUE;
    }
    return     FALSE;
    });

    foreach (new     RecursiveIteratorIterator($files) as $file) {
    echo     $file->getPathname() . PHP_EOL;
    }

    ?>

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    User Contributed Notes 2 notes

    up
    8
    a dot belloundja at gmail dot com
    11 years ago
    Here is a code that may implement similar functionality in PHP 5.2 or 5.3 :

    <?php

    class RecursiveCallbackFilterIterator extends RecursiveFilterIterator {

    public function     __construct ( RecursiveIterator $iterator, $callback ) {

    $this->callback = $callback;

    parent::__construct($iterator);

    }

    public function     accept () {

    $callback = $this->callback;

    return     $callback(parent::current(), parent::key(), parent::getInnerIterator());

    }

    public function     getChildren () {

    return new     self($this->getInnerIterator()->getChildren(), $this->callback);

    }

    }

    ?>
    up
    -2
    Anonymous
    12 years ago
    Note that the following filters out both files and directories whos names start with the letter "T". The important thing here is that since the function returns false for a directory entry whos name starts with T, the directory is also not traversed recursively.

    <?php
    $doesntStartWithLetterT     = function ($current) {
    return     $current->getFileName()[0] !== 'T';
    };

    $rdi = new RecursiveDirectoryIterator(__DIR__);
    $files = new RecursiveCallbackFilterIterator($rdi, $doesntStartWithLetterT);
    foreach (new     RecursiveIteratorIterator($files) as $file) {
    echo     $file->getPathname() . PHP_EOL;
    }
    ?>
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