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The FilterIterator class

(PHP 5 >= 5.1.0)

简介

这个抽象类的遍历并过滤出不想要的值.这个类应该被实现了迭代过滤器的类继承 FilterIterator::accept() 方法必须被子类实现.

类摘要

abstract FilterIterator extends IteratorIterator implements OuterIterator {
public abstract bool accept ( void )
public __construct ( Iterator $iterator )
public mixed current ( void )
public Iterator getInnerIterator ( void )
public mixed key ( void )
public void next ( void )
public void rewind ( void )
public bool valid ( void )
}

Table of Contents

  • FilterIterator::accept — Check whether the current element of the iterator is acceptable
  • FilterIterator::__construct — Construct a filterIterator
  • FilterIterator::current — Get the current element value
  • FilterIterator::getInnerIterator — Get the inner iterator
  • FilterIterator::key — Get the current key
  • FilterIterator::next — Move the iterator forward
  • FilterIterator::rewind — Rewind the iterator
  • FilterIterator::valid — Check whether the current element is valid

用户评论:

[#1] Anonymous [2014-05-27 08:01:59]

A little test about the function call order:

<?php

class TestIterator extends IteratorIterator
{
    public function 
key()
    {
        echo  
__FUNCTION__PHP_EOL;
        return 
parent::key();
    }

    public function 
next()
    {
        echo  
__FUNCTION__PHP_EOL;
        return 
parent::next();
    }

    public function 
rewind()
    {
        echo  
__FUNCTION__PHP_EOL;
        return 
parent::rewind();
    }

    public function 
valid()
    {
        echo  
__FUNCTION__PHP_EOL;
        return 
parent::valid();
    }
}

class 
TestFilterIterator extends FilterIterator
{
    public function 
accept()
    {
        echo  
__FUNCTION__PHP_EOL;
        return 
true;
    }
}

$iterator = new ArrayIterator(array('a''b''c'));

foreach (new 
TestFilterIterator(new TestIterator($iterator)) as $k => $v) {
    echo 
PHP_EOL;
}

?>


This will output the following:

rewind
valid
key
accept

next
valid
key
accept

next
valid
key
accept

next
valid

[#2] Venelin Vulkov [2008-11-05 00:36:49]

The code below is a simple example of usage . Note that the method which does the actual job is accept. 

<?php
class UserFilter extends FilterIterator 
{
    private 
$userFilter;
    
    public function 
__construct(Iterator $iterator $filter )
    {
        
parent::__construct($iterator);
        
$this->userFilter $filter;
    }
    
    public function 
accept()
    {
        
$user $this->getInnerIterator()->current();
        if( 
strcasecmp($user['name'],$this->userFilter) == 0) {
            return 
false;
        }        
        return 
true;
    }
}

$array = array(
array(
'name' => 'Jonathan','id' => '5'),
array(
'name' => 'Abdul' ,'id' => '22')
);

$object = new ArrayObject($array);

// Note it is case insensitive check in our example due the usage of strcasecmp function
$iterator = new UserFilter($object->getIterator(),'abdul');

foreach (
$iterator as $result) {
    echo 
$result['name'];
}



?>

Regards.

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