Custom Filters

Filters must implement Centum\Interfaces\Filter\FilterInterface.

Filters only require one public method:

• public function filter(mixed $value): mixed Accepts any input and returns the filtered output.

Example: Lowercase Filter

A simple filter that converts a string to lowercase:

namespace App\Filters;

use Centum\Interfaces\Filter\FilterInterface;

class LowercaseFilter implements FilterInterface
{
    public function filter(mixed $value): mixed
    {
        return mb_strtolower($value);
    }
}

See also Centum\Filter\String\ToLower for a built-in implementation.

Example: Filter with Dependency Injection

You can create more advanced filters by injecting dependencies, such as services or formatters:

namespace App\Filters;

use Centum\Interfaces\Filter\FilterInterface;
use NumberFormatter;

class NumberFormatterFilter implements FilterInterface
{
    public function __construct(
        protected readonly NumberFormatter $numberFormatter
    ) {
    }

    public function filter(mixed $value): mixed
    {
        return $this->numberFormatter->format($value);
    }
}

Usage

Custom filters can be used anywhere you need to transform or sanitize data, such as before validation or storage.

$filter = new \App\Filters\LowercaseFilter();

$result = $filter->filter("HELLO WORLD"); // "hello world"