Array Filter Input

ArrayFilterInput.php

<?php

class ArrayFilterInput implements \ArrayAccess
{
    protected $input;
    protected $cache = array();

    public function __construct($input)
    {
        $this->input = $input;
    }

    public function offsetExists($offset)
    {
        if (array_key_exists($offset, $this->cache)) {
            return true;
        }

        return filter_has_var($this->input, $offset);
    }

    public function offsetGet($offset)
    {
        if (array_key_exists($offset, $this->cache)) {
            return $this->cache[$offset];
        }

        $value = filter_input($this->input, $offset);

        if ($value === false) {
            throw new \LogicException('Error');
        }

        return $this->cache[$offset] = $value;
    }

    public function offsetSet($offset, $value)
    {
        $this->cache[$offset] = $value;
    }

    public function offsetUnset($offset)
    {
        unset($this->cache[$offset]);
    }
}

ArrayFilterInputTest.php

<?php

class ArrayFilterInputTest extends \PHPUnit_Framework_TestCase
{
    public function getMockForArrayFilterInput($input)
    {
        $object = $this->getMockForAbstractClass('ArrayFilterInput');

        $reflection = new ReflectionClass($object);
        $reflectionProperty = $reflection->getProperty('input');
        $reflectionProperty->setAccessible(true);
        $reflectionProperty->setValue($object, $input);

        return $object;
    }

    public function testExists()
    {
        $server = $this->getMockForArrayFilterInput(INPUT_SERVER);

        $this->assertFalse(isset($server['NOT_FOUND']));
        $this->assertTrue(isset($server['PHP_SELF']));
    }

    public function testGet()
    {
        $server = $this->getMockForArrayFilterInput(INPUT_SERVER);

        $this->assertEquals($_SERVER['PHP_SELF'], $server['PHP_SELF']);
        $this->assertEquals($_SERVER['SCRIPT_NAME'], $server['SCRIPT_NAME']);
    }

    public function testSet()
    {
        $server = $this->getMockForArrayFilterInput(INPUT_SERVER);
        $server['NEW_VALUE'] = 'Good Morning PHP';

        $this->assertEquals('Good Morning PHP', $server['NEW_VALUE']);
    }

    public function testUnset()
    {
        $server = $this->getMockForArrayFilterInput(INPUT_SERVER);
        $server['NEW_VALUE'] = 'Good Morning PHP';

        unset($server['PHP_SELF']);
        unset($server['NEW_VALUE']);

        $this->assertTrue(isset($server['PHP_SELF']));
        $this->assertFalse(isset($server['NEW_VALUE']));
        $this->assertNull($server['NEW_VALUE']);
    }
}

superglobals.php

<?php
/**
 * When PHP INI directive `variables_order` is set to "" [0] then the
 * superglobals are disabled but filter_input is still usable to
 * retrieve it's values.
 *
 * [0]: https://bugs.php.net/bug.php?id=68008
 */

require_once __DIR__ . '/ArrayFilterInput.php';

$_GET = new ArrayFilterInput(INPUT_GET);
$_POST = new ArrayFilterInput(INPUT_POST);
$_REQUEST = new ArrayFilterInput(INPUT_REQUEST);
//$_FILES = null;
$_COOKIE = new ArrayFilterInput(INPUT_COOKIE);
$_SESSION = new ArrayFilterInput(INPUT_SESSION);
$_SERVER = new ArrayFilterInput(INPUT_SERVER);
$_ENV = new ArrayFilterInput(INPUT_ENV);