README

HTTP Precondition for Laravel

Installation

To install, run the following command in your project:

composer require onursimsek/precondition

Usage

A client has requested a resource from you (GET), and after a while wants to update the resource and send it back to you (PUT). Meanwhile, another client has received the same resource (GET) and updated it before the first client (PUT). In this case, the first client's update will be based on an incorrect copy and will ignore the second client's updates. This is called lost update problem.

In such a case, you can return 428 Precondition Required to the first client and ask it to pull the resource again.

This package allows you to do this easily. All you need to do is create a Validator class and add it as an attribute to the corresponding controller method.

use Illuminate\Http\Request;
use OnurSimsek\Precondition\Validators\PreconditionValidator;

class LostUpdateValidator extends PreconditionValidator
{
    public function parameter(Request $request)
    {
        return $request->header('If-Unmodified-Since');
    }

    public function __invoke(Request $request): bool
    {
        return $this->parameter($request) == $request->route('article')->updated_at;
    }
}

use App\Models\Article;
use App\Http\Requests\UpdateArticleRequest;
use OnurSimsek\Precondition\Attributes\Precondition;

class ArticleController
{
    #[Precondition(LostUpdateValidator::class)]
    public function update(Article $article, UpdateArticleRequest $request)
    {
        $article->fill($request->validated())
        $article->save();

        return response()->json();
    }
}

Finally, you need to add precondition middleware to the route you want to use.

Route::put('/articles/{:article}', [ArticleController::class, 'update'])
    ->middleware(['precondition']);

You can also use this package if you have any conditions for a request to be fulfilled. For example some examples;

Github Sample

You are prompted to re-type the repository name before deleting a repository.

use Illuminate\Http\Request;
use OnurSimsek\Precondition\Validators\PreconditionValidator;

class DeleteRepositoryValidator extends PreconditionValidator
{
    public function parameter(Request $request)
    {
        return $request->input('repository_name');
    }

    public function __invoke(Request $request): bool
    {
        return $this->parameter($request) == $request->route('repository')->name;
    }
}

Note: If the repo name is invalid, the response returns with a status code of 412 Precondition Failed.

SMS Verification

SMS verification is a mandatory step in the payment process.

use Illuminate\Http\Request;
use OnurSimsek\Precondition\Validators\PreconditionValidator;

class SmsValidator extends PreconditionValidator
{
    public function preProcess(): void
    {
        cache()->set('sms', '123456');
    }

    public function parameter(Request $request)
    {
        return $request->input('sms_code');
    }

    public function __invoke(Request $request): bool
    {
        return $this->parameter($request) == cache()->get('sms');
    }
}

Optional Verification

If you want to validate on a case-by-case basis, you can use the when method as follows.

use Illuminate\Http\Request;
use OnurSimsek\Precondition\Validators\PreconditionValidator;

class PrivateArticleValidator extends PreconditionValidator
{
    public function when(Request $request) 
    {
        return $request->route('article')->is_private;
    }

    public function parameter(Request $request)
    {
        return $request->header('X-Article-Secret-Code');
    }

    public function __invoke(Request $request): bool
    {
        return $this->parameter($request) == $request->route('article')->secret_code;
    }
}

You can use the messages() method in the validator class to customize the error messages.

public function messages(): array
{
    return [
        'required' => 'Enter the sms code sent to your phone.',
        'failed' => 'Incorrect sms code!',
    ];
}

Testing

composer test

Changelog

Please see CHANGELOG for more information on what has changed recently.

Contributing

Please see CONTRIBUTING for details.

Security Vulnerabilities

Please review our security policy on how to report security vulnerabilities.

Credits

• Onur Simsek
• All Contributors

License

The MIT License (MIT). Please see License File for more information.