How to deal with a date provided as an empty string

[Scumi]

What can I do when a date is provided as empty string during Data creation?

As far as I see, this package can deal with:

• date attribute not being provided at all (by setting property to Optional)
• date attribute being NULL (by setting property to null)
• date attribute being set in various formats (via Casts and Transformers)

However, when I receive data where a date is provided as an empty string, I get an error
Could not cast date `` into a `Carbon\Carbon` using formats: Y-m-d, d.m.Y

The incoming data is from an external API so I have no possibility of tampering with it before (other than ugly kludges).

[iamrgroot]

I think you should solve this using a custom cast: https://spatie.be/docs/laravel-data/v2/as-a-data-transfer-object/casts

Within the cast you can do anything you want with an empty string (convert to null, convert to now or whatever). For example, I use this cast to use Carbon::parse instead of a fixed format:

class CarbonParseCast extends Cast
{
    public function __construct(
        protected ?string $type = null,
    ) {
    }

    /**
     * @param array<string,mixed> $context
     */
    public function cast(DataProperty $property, mixed $value, array $context): DateTimeInterface|Uncastable
    {
        try {
            $type = $this->type ?? Carbon::class;

            return $type::parse($value);
        } catch (\Throwable $th) {
        }

        return Uncastable::create();
    }
}

[Patabugen]

I wanted to maintain the benefits of the built in DateTimeInterfaceCast, just return null if the string is empty.

Here's what I came up with:

<?php
namespace App\Data\Casts;

use Spatie\LaravelData\Support\DataProperty;
use Spatie\LaravelData\Casts\DateTimeInterfaceCast;
use DateTimeInterface;
use Spatie\LaravelData\Casts\Cast;
use Spatie\LaravelData\Casts\Uncastable;

class NullableDateTimeInterfaceCast implements Cast
{
    public function cast(DataProperty $property, mixed $value, array $context): null|DateTimeInterface|Uncastable
    {
        if ($value == '') {
            return null;
        }
        $caster = new DateTimeInterfaceCast();
        return $caster->cast($property, $value, $context);
    }
}

[EMeDesign]

Another method is add a pipeline to fix the empty string,

This is mine:

<?php

namespace App\Data\DataPipes;

use Spatie\LaravelData\Casts\DateTimeInterfaceCast;
use Spatie\LaravelData\DataPipes\DataPipe;
use Spatie\LaravelData\Support\Creation\CreationContext;
use Spatie\LaravelData\Support\DataClass;

class PrepareDateTimeForPropertiesCastDataPipe implements DataPipe
{

    /**
     * This data pipeline prepare a fixed date time format for date time cast.
     *
     * Example fixed value:
     * <code>
     *     "" => null
     * </code>
     *
     * @param array<array-key, mixed> $properties
     *
     * @return array<array-key, mixed>
     */
    public function handle(mixed $payload, DataClass $class, array $properties, CreationContext $creationContext): array
    {
        foreach ($properties as $name => $value) {
            $dataProperty = $class->properties[$name] ?? null;

            if ($dataProperty === null) {
                continue;
            }

            if (is_a($dataProperty->cast, DateTimeInterfaceCast::class)) {
                if ($value === "") {
                    $properties[$name] = null;
                }
            }
        }

        return $properties;
    }
}

Then we only need to override the pipeline() method in our date class:

<?php

namespace App\Data;

use App\Data\DataPipes\PrepareDateTimeForPropertiesCastDataPipe;
use Illuminate\Support\Carbon;
use Spatie\LaravelData\Attributes\WithCast;
use Spatie\LaravelData\Casts\DateTimeInterfaceCast;
use Spatie\LaravelData\Data;
use Spatie\LaravelData\DataPipeline;
use Spatie\LaravelData\DataPipes\{AuthorizedDataPipe,
    CastPropertiesDataPipe,
    DefaultValuesDataPipe,
    InjectPropertyValuesPipe,
    MapPropertiesDataPipe,
    ValidatePropertiesDataPipe
};

class MyData extends Data
{
    public function __construct(
        #[WithCast(DateTimeInterfaceCast::class, format: 'Y-m-d')]
        public ?Carbon $date,
    ) {}

    #[\Override]
    public static function pipeline(): DataPipeline
    {
        return DataPipeline::create()
            ->into(static::class)
            ->through(AuthorizedDataPipe::class)
            ->through(MapPropertiesDataPipe::class)
            ->through(InjectPropertyValuesPipe::class)
            ->through(ValidatePropertiesDataPipe::class)
            ->through(DefaultValuesDataPipe::class)
            ->through(PrepareDateTimeForPropertiesCastDataPipe::class) // Add pipeline before casting
            ->through(CastPropertiesDataPipe::class);
    }
}