[Support] precognition requests via middleware

[zdravstvuy1714]

implement support for laravel/framework#44339 Laravel feature

[ragulka]

The following workaround adds Precognition support to Laravel Data. It intercepts the pipeline if the payload is a precognitive request, then filters the rules based on the precognition headers and validates the payload. Otherwise, it will continue as usual.

PrecognitivelyValidatePropertiesDataPipe.php:

use Illuminate\Http\Request;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Validator;
use Spatie\LaravelData\DataPipes\ValidatePropertiesDataPipe;
use Spatie\LaravelData\Support\DataClass;

class PrecognitivelyValidatePropertiesDataPipe extends ValidatePropertiesDataPipe
{
    public function handle(mixed $payload, DataClass $class, Collection $properties): Collection
    {
        if ($payload instanceof Request && $payload->isPrecognitive()) {
            Validator::make(
                $properties->toArray(),
                $payload->filterPrecognitiveRules(($class->name)::getValidationRules($properties->toArray())),
            )->validate();

            return $properties;
        }

        return parent::handle($payload, $class, $properties);
    }
}

AppServiceProvider.php:

class AppServiceProvider extends ServiceProvider
{
    public function boot(): void
    {
        $this->app->bind(ValidatePropertiesDataPipe::class, PrecognitivelyValidatePropertiesDataPipe::class);
    }
}

[ragulka]

One thing to note about the workaround above is that if you overwrite the validator in your data class to customize validation rules, then those modified rules won't be show up when calling Data::getValidationRules.

I discovered this by working on something different, but it seems like Data::getValidationRules and the actual data validation pipeline build validation rules using different mechanisms, which to me seems like a design issue, because there is no single source of truth.

[ragulka]

I found that overwriting getValidationRules() to use the dataValidatorResolver solves the issue with custom validators and ensures there's a single source of truth for validation rules:

class MyData {

    public static function getValidationRules(array $payload): array
    {
        return DataContainer::get()->dataValidatorResolver()->execute(
            static::class,
            $payload,
        )->getRules();
    }
}

This is what the ValidatableData::validate() method does before actually validating the payload.

laravel-data/src/Concerns/ValidateableData.php

Lines 26 to 29 in 48b3708

	$validator = DataContainer::get()->dataValidatorResolver()->execute(
	static::class,
	$payload,
	);

@rubenvanassche I'm curious why ValidatableData::getValidationRules does not not use the same method? Some sort of overhead concern?

[rubenvanassche]

Yeah felt a bit useless to create a full validator and then only take the rules from it while we have some dedicated Resolvers for it which could be called separately.

That being said, I don't think this will be the biggest performance issue so if it can allow precognition to be added then you've got my go signal to rewrite it!

[valh1996]

Ok, I was thinking I had plenty of bugs with Laravel precognition before I realized that.... it is not support atm (my bad...).

So, I'm trying your solution @ragulka (ValidatePropertiesDataPipe).
But do you know if this is supposed to work with nested rules/data?

My precognitive header looks like:

property.0.start

But it has no effect on validation,

$payload->filterPrecognitiveRules(($class->name)::getValidationRules($properties)),

returns only first level rules (property).

Ay idea ?

EDIT:
overwriting getValidationRules() is the way to go for the moment.

[valh1996]

For those who might find it helpful, I had to include the Data's custom messages and attributes in the DataPipe, otherwise these are the default error messages.

public function handle(
        mixed $payload,
        DataClass $class,
        array $properties,
        CreationContext $creationContext
): array 
{
  if ($payload instanceof Request && $payload->isPrecognitive()) {
    Validator::make(
      $properties,
      $payload->filterPrecognitiveRules(($class->name)::getValidationRules($properties)),
+     ($class->name)::messages() ?? [],
+     ($class->name)::attributes() ?? [],
    )
      ->after(Precognition::afterValidationHook($payload))
      ->validate();
  }
  
  return parent::handle($payload, $class, $properties, $creationContext);
}