PHP Velho Oeste 2024

The FilterIterator class

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

Introduction

This abstract iterator filters out unwanted values. This class should be extended to implement custom iterator filters. The FilterIterator::accept() must be implemented in the subclass.

Class synopsis

abstract class FilterIterator extends IteratorIterator {
/* Methods */
public __construct(Iterator $iterator)
public accept(): bool
public current(): mixed
public key(): mixed
public next(): void
public rewind(): void
public valid(): bool
/* Inherited methods */
}

Table of Contents

add a note add a note

User Contributed Notes 3 notes

up
16
Venelin Vulkov
15 years ago
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'];
}

/* Outputs Jonathan */

?>
Regards.
up
5
Anonymous
9 years ago
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
up
0
Anonymous
2 years ago
Filter object collection by method:
<?php
/**
  * @method object current()
  */
class CollectionFilterIterator extends FilterIterator
{
     private
$methodName;
     private
$methodArguments;

     public function function
__construct(Iterator $collection, string $methodName, array $methodArguments = [])
     {
            
parent::__construct($collection);
            
$this->methodName = $methodName;
            
$this->methodArguments = array_values($methodArguments);
     }

     public function
accept(): bool
    
{
             return (bool)
$this->current()->{$this->methodName}(...$this->methodArguments);
            
// or call_user_func_array([$this->current(), $this->methodName], $this->methodArguments);
    
}
}
?>
To Top