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The ParentIterator class

(PHP 5 >= 5.1.0)

简介

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

类摘要

ParentIterator extends RecursiveFilterIterator implements RecursiveIterator , OuterIterator , Traversable , Iterator {
/* 方法 */
public bool accept ( void )
public __construct ( RecursiveIterator $iterator )
public ParentIterator getChildren ( void )
public bool hasChildren ( void )
public void next ( void )
public void rewind ( void )
}

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PHP手册 - N: The ParentIterator class

用户评论:

Anonymous (20-Dec-2011 03:55)

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);
?>