Using custom filters alongside default filters on array properties

[ZeroGodForce]

I've written a custom filter based on filter_var_array() and inspired by the FilterVars::class to allow an array of repeating arrays (e.g. order lines) to be validated on a per-element level. For example:

<?php

namespace App\Filters;

use ArondeParon\RequestSanitizer\Contracts\Sanitizer;

class FilterRepeatingVarArray implements Sanitizer
{
    protected array $fields;

    public function __construct($fields = [])
    {
        $this->fields = $fields;
    }

    /**
     * Sanitize the nested array using the native PHP function: filter_var_array()
     * @param $input
     * @return array|null
     * @see https://www.php.net/manual/en/function.filter-var-array.php
     */
    public function sanitize($input): ?array
    {
        if (is_null($input)) {
            return $input;
        }

        $sanitized = [];
        foreach ($input as $item) {
            $sanitized[] = filter_var_array($item, $this->fields);
        }

        return $sanitized;
    }
}

Then in the form request it's defined like this:

    protected array $sanitizers = [
        ...
        'order_line' => [
            FilterRepeatingVarArray::class => [
                'fields' => [
                    'quantity' => [
                        'filter' => FILTER_VALIDATE_INT,
                    ],
                    'price' => [
                        'filter' => FILTER_SANITIZE_NUMBER_FLOAT,
                        'flags' => FILTER_FLAG_ALLOW_FRACTION,
                        'options' => null,
                    ],
                ],
            ],
        ],
        ...
    ];

This appears to be working fine, but I'm not actually sure how I can apply any of the package's default filters to this kind of 2D array. Ironically, it's brought me back to the original reason I wrote this custom filter; I'm not sure how (or if it's currently possible) to run filter classes on nested array elements?

Thanks for the library, it's ace!