PHP Velho Oeste 2024

The FilterIterator class

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

Einführung

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.

Klassenbeschreibung

abstract class FilterIterator extends IteratorIterator {
/* Methoden */
public __construct(Iterator $iterator)
public accept(): boolvoid
public current(): mixedvoid
public key(): mixedvoid
public next(): voidvoid
public rewind(): voidvoid
public valid(): boolvoid
/* Geerbte Methoden */
}

Inhaltsverzeichnis

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User Contributed Notes 3 notes

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23
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);
}
}
?>
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