[Feature Request] Add enum collection cast

[Jacques Florian]

Hello, I propose a cast that could be interesting to add to the library.

<?php

namespace App\Casts;

use Illuminate\Contracts\Database\Eloquent\Castable;
use Illuminate\Contracts\Database\Eloquent\CastsAttributes;
use Illuminate\Support\Collection;

class AsEnumCollection implements Castable
{
    /**
     * @param array $arguments
     * @return CastsAttributes
     */
    public static function castUsing(array $arguments): CastsAttributes
    {
        return new class($arguments) implements CastsAttributes
        {
            protected array $arguments;

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

            public function get($model, $key, $value, $attributes): ?Collection
            {
                if (! isset($attributes[$key])) {
                    return null;
                }

                $data = $attributes[$key];

                if (! is_array($data)) {
                    return null;
                }

                $enumClass = $this->arguments[0];

                return (new Collection($data))->map(function ($value) use ($enumClass) {
                    return is_subclass_of($enumClass, \BackedEnum::class)
                        ? $enumClass::from($value)
                        : constant($enumClass.'::'.$value);
                });
            }

            public function set($model, $key, $value, $attributes): array
            {
                $value = $value !== null
                    ? (new Collection($value))->map(function ($enum) {
                        return $this->getStorableEnumValue($enum);
                    })->jsonSerialize()
                    : null;

                return [$key => $value];
            }

            protected function getStorableEnumValue($enum)
            {
                if (is_string($enum) || is_int($enum)) {
                    return $enum;
                }

                return $enum instanceof \BackedEnum ? $enum->value : $enum->name;
            }
        };
    }

    /**
     * Specify the Enum for the cast.
     *
     * @param  class-string  $class
     * @return string
     */
    public static function of(string $class): string
    {
        return static::class.':'.$class;
    }
}

Usage:

use App\Enums\ServerStatus;
use Illuminate\Database\Eloquent\Casts\AsEnumCollection;
 
/**
 * Get the attributes that should be cast.
 *
 * @return array<string, string>
 */
protected function casts(): array
{
    return [
        'statuses' => AsEnumCollection::of(ServerStatus::class),
    ];
}

[David van der Tuijn]

Is the cast() method already implemented in this library?

I can only see the $casts variable approach in the documentation: