The RecursiveCallbackFilterIterator class

(PHP 5 >= 5.4.0, PHP 7)

简介

类摘要

RecursiveCallbackFilterIterator extends CallbackFilterIterator implements OuterIterator , RecursiveIterator {
/* 方法 */
public __construct ( RecursiveIterator $iterator , string $callback )
public RecursiveCallbackFilterIterator getChildren ( void )
public bool hasChildren ( void )
/* 继承的方法 */
public string CallbackFilterIterator::accept ( void )
}

范例

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;
}

?>

Table of Contents

User Contributed Notes

a dot belloundja at gmail dot com 02-Jan-2013 08:26
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);
       
    }
   
}

?>
Anonymous 11-Dec-2011 10:31
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;
}
?>