略微加速

PHP官方手册 - 互联网笔记

PHP - Manual: RecursiveCallbackFilterIterator

2024-04-27

The RecursiveCallbackFilterIterator class

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

简介

类摘要

class RecursiveCallbackFilterIterator extends CallbackFilterIterator implements RecursiveIterator {
/* 方法 */
public __construct(RecursiveIterator $iterator, callable $callback)
public hasChildren(): bool
/* 继承的方法 */
public FilterIterator::accept(): bool
public FilterIterator::next(): void
public FilterIterator::rewind(): void
public FilterIterator::valid(): bool
public IteratorIterator::next(): void
}

范例

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

示例 #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.

示例 #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;
}

?>

目录

add a noteadd a note

User Contributed Notes 2 notes

up
9
a dot belloundja at gmail dot com
9 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
-1
Anonymous
10 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;
}
?>

官方地址:https://www.php.net/manual/en/class.recursivecallbackfilteriterator.php

北京半月雨文化科技有限公司.版权所有 京ICP备12026184号-3