Laravel Validated DTO

Data Transfer Objects with validation for Laravel applications

Documentation

Features

Easily integrate it with your current project
Data validation the same way you validate a Request
Easily define custom validation messages
Support for typed properties
Type Casting out-of-the-box for your DTOs properties
Support casting of nested data
Easily create custom Type Casters for your own needs
Custom Data Mapping
Use DTOs for wrapping, typing and transforming API responses
Laravel Livewire support

Installation

composer require wendelladriel/laravel-validated-dto

Configuration

Publish the config file:

php artisan vendor:publish --provider="WendellAdriel\ValidatedDTO\Providers\ValidatedDTOServiceProvider" --tag=config

The configuration file will look like this:

<?php

return [
    /*
    |--------------------------------------------------------------------------
    | REQUIRE CASTING
    |--------------------------------------------------------------------------
    |
    | If this is set to true, you must configure a cast type for all properties of your DTOs.
    | If a property doesn't have a cast type configured it will throw a
    | \WendellAdriel\ValidatedDTO\Exceptions\MissingCastTypeException exception
    |
    */
    'require_casting' => false,
];

Why use this package

Data Transfer Objects (DTOs) are objects that are used to transfer data between systems. DTOs are typically used in applications to provide a simple, consistent format for transferring data between different parts of the application, such as between the user interface and the business logic.

This package provides a base DTO Class that can validate the data when creating a DTO. But why should we do this instead of using the standard Request validation?

Imagine that now you want to do the same action that you do in an endpoint on a CLI command for example. If your validation is linked to the Request you'll have to implement the same validation again.

With this package you define the validation once and can reuse it where you need, making your application more maintainable and decoupled.

Generating DTOs

You can create DTOs using the make:dto command:

php artisan make:dto UserDTO

The DTOs are going to be created inside app/DTOs.

Defining DTO Properties

You can define typed properties in your DTO outside the constructor:

class UserDTO extends ValidatedDTO
{
    public string $name;

    public string $email;

    public string $password;
}

Remember that the property types must be compatible with the Cast Type you define for them.

Defining Validation Rules

You can validate data in the same way you validate Request data:

class UserDTO extends ValidatedDTO
{
    /**
     * @return array
     */
    protected function rules(): array
    {
        return [
            'name'     => ['required', 'string'],
            'email'    => ['required', 'email'],
            'password' => [
                'required',
                Password::min(8)
                    ->mixedCase()
                    ->letters()
                    ->numbers()
                    ->symbols()
                    ->uncompromised(),
            ],
        ];
    }
}

Creating DTO instances

You can create a DTO instance on many ways:

From arrays

$dto = new UserDTO([
    'name' => 'John Doe',
    'email' => '[email protected]',
    'password' => 's3CreT!@1a2B'
]);

You can also use the fromArray static method:

$dto = UserDTO::fromArray([
    'name' => 'John Doe',
    'email' => '[email protected]',
    'password' => 's3CreT!@1a2B'
]);

From JSON strings

$dto = UserDTO::fromJson('{"name": "John Doe", "email": "[email protected]", "password": "s3CreT!@1a2B"}');

From Request objects

public function store(Request $request): JsonResponse
{
    $dto = UserDTO::fromRequest($request);
}

From Eloquent Models

$user = new User([
    'name' => 'John Doe',
    'email' => '[email protected]',
    'password' => 's3CreT!@1a2B'
]);

$dto = UserDTO::fromModel($user);

Beware that the fields in the $hidden property of the Model won't be used for the DTO.

From Artisan Commands

You have three ways of creating a DTO instance from an Artisan Command:

From the Command Arguments

<?php

use App\DTOs\UserDTO;
use Illuminate\Console\Command;

class CreateUserCommand extends Command
{
    protected $signature = 'create:user {name} {email} {password}';

    protected $description = 'Create a new User';

    /**
     * Execute the console command.
     *
     * @return int
     *
     * @throws ValidationException
     */
    public function handle()
    {
        $dto = UserDTO::fromCommandArguments($this);
    }
}

From the Command Options

<?php

use App\DTOs\UserDTO;
use Illuminate\Console\Command;

class CreateUserCommand extends Command
{
    protected $signature = 'create:user { --name= : The user name }
                                        { --email= : The user email }
                                        { --password= : The user password }';

    protected $description = 'Create a new User';

    /**
     * Execute the console command.
     *
     * @return int
     *
     * @throws ValidationException
     */
    public function handle()
    {
        $dto = UserDTO::fromCommandOptions($this);
    }
}

From the Command Arguments and Options

<?php

use App\DTOs\UserDTO;
use Illuminate\Console\Command;

class CreateUserCommand extends Command
{
    protected $signature = 'create:user {name}
                                        { --email= : The user email }
                                        { --password= : The user password }';

    protected $description = 'Create a new User';

    /**
     * Execute the console command.
     *
     * @return int
     *
     * @throws ValidationException
     */
    public function handle()
    {
        $dto = UserDTO::fromCommand($this);
    }
}

Accessing DTO data

After you create your DTO instance, you can access any properties like an object:

$dto = new UserDTO([
    'name' => 'John Doe',
    'email' => '[email protected]',
    'password' => 's3CreT!@1a2B'
]);

$dto->name; // 'John Doe'
$dto->email; // '[email protected]'
$dto->password; // 's3CreT!@1a2B'

If you pass properties that are not listed in the rules method of your DTO, this data will be ignored and won't be available in your DTO:

$dto = new UserDTO([
    'name' => 'John Doe',
    'email' => '[email protected]',
    'password' => 's3CreT!@1a2B',
    'username' => 'john_doe', 
]);

$dto->username; // THIS WON'T BE AVAILABLE IN YOUR DTO

Defining Default Values

Sometimes we can have properties that are optional and that can have default values. You can define the default values for your DTO properties in the defaults function:

class UserDTO extends ValidatedDTO
{
    /**
     * @return array
     */
    protected function rules(): array
    {
        return [
            'name'     => ['required', 'string'],
            'email'    => ['required', 'email'],
            'username' => ['sometimes', 'string'],
            'password' => [
                'required',
                Password::min(8)
                    ->mixedCase()
                    ->letters()
                    ->numbers()
                    ->symbols()
                    ->uncompromised(),
            ],
        ];
    }
    
    /**
     * Defines the default values for the properties of the DTO.
     *
     * @return array
     */
    protected function defaults(): array
    {
        return [
            'username' => Str::snake($this->name),
        ];
    }
}

With the DTO definition above you could run:

$dto = new UserDTO([
    'name' => 'John Doe',
    'email' => '[email protected]',
    'password' => 's3CreT!@1a2B'
]);

$dto->username; // 'john_doe'

Converting DTO data

You can convert your DTO to some formats:

To array

$dto = new UserDTO([
    'name' => 'John Doe',
    'email' => '[email protected]',
    'password' => 's3CreT!@1a2B',
]);

$dto->toArray();
// [
//     "name" => "John Doe",
//     "email" => "[email protected]",
//     "password" => "s3CreT!@1a2B",
// ]

To JSON string

$dto = new UserDTO([
    'name' => 'John Doe',
    'email' => '[email protected]',
    'password' => 's3CreT!@1a2B',
]);

$dto->toJson();
// '{"name":"John Doe","email":"[email protected]","password":"s3CreT!@1a2B"}'

$dto->toJson(true); // YOU CAN CALL IT LIKE THIS TO PRETTY PRINT YOUR JSON
$dto->toPrettyJson(); // OR LIKE THIS
// {
//     "name": "John Doe",
//     "email": "[email protected]",
//     "password": "s3CreT!@1a2B"
// }

To Eloquent Model

$dto = new UserDTO([
    'name' => 'John Doe',
    'email' => '[email protected]',
    'password' => 's3CreT!@1a2B',
]);

$dto->toModel(\App\Models\User::class);
// App\Models\User {#3776
//     name: "John Doe",
//     email: "[email protected]",
//     password: "s3CreT!@1a2B",
// }

Mapping DTO properties

Mapping data before validation

Sometimes the data you have to validate is not the same you want in your DTO. You can use the mapBeforeValidation method to map your data before the validation and the DTO instantiation occurs:

protected function mapBeforeValidation(): array
{
    return [
        'full_name' => 'name',
    ];
}

The code above will map the full_name property to the name property before the validation and the DTO instantiation. So your Request/Array/etc can have a full_name property and your DTO will have a name property instead.

Mapping nested data to flat data

Imagine that you have a NameDTO like this:

class NameDTO extends ValidatedDTO
{
    public string $first_name;

    public string $last_name;

    protected function rules(): array
    {
        return [
            'first_name' => ['required', 'string'],
            'last_name' => ['required', 'string'],
        ];
    }
}

But in your Request the data comes like this:

[
    'name' => [
        'first_name' => 'John',
        'last_name' => 'Doe',
    ],
]

You can add this to the mapBeforeValidation method:

protected function mapBeforeValidation(): array
{
    return [
        'first_name' => 'name.first_name',
        'last_name' => 'name.last_name',
    ];
}

This way, the first_name and last_name properties will be mapped to the name.first_name and name.last_name properties of your request.

Mapping data before export

Sometimes the data you have in your DTO is not the same you want to your Model, Array, JSON. You can use the mapBeforeExport method to map your data before exporting your DTO to another structure:

protected function mapBeforeExport(): array
{
    return [
        'name' => 'username',
    ];
}

The code above will map the name property to the username property before exporting your DTO to another structure. So the result structure will have a username property instead of a name property.

Mapping nested data to flat data

Imagine that you have a UserDTO like this:

class UserDTO extends ValidatedDTO
{
    public NameDTO $name;

    public string $email;

    protected function rules(): array
    {
        return [
            'name' => ['required', 'array'],
            'email' => ['required', 'email'],
        ];
    }

But your User model is like this:

class User extends Model
{
    protected $fillable = [
        'first_name',
        'last_name',
        'email',
    ];
}

You can add this to the mapBeforeExport method:

protected function mapBeforeExport(): array
{
    return [
        'name.first_name' => 'first_name',
        'name.last_name' => 'last_name',
    ];
}

This way, when calling the toModel method, the name.first_name and name.last_name properties of your DTO will be mapped to the first_name and last_name properties of your Model.

You can combine both methods to map your data before validation and before export. If you combine the both examples above your request will have a full_name property, your DTO will have a name property and when exported the result will have a username property.

Customizing Error Messages, Attributes and Exceptions

You can define custom messages and attributes implementing the messages and attributes methods:

/**
 * Defines the custom messages for validator errors.
 *
 * @return array
 */
public function messages(): array
{
    return [];
}

/**
 * Defines the custom attributes for validator errors.
 *
 * @return array
 */
public function attributes(): array
{
    return [];
}

You can define custom Exceptions implementing the failedValidation method:

/**
 * Handles a failed validation attempt.
 *
 * @return void
 *
 * @throws ValidationException
 */
protected function failedValidation(): void
{
    throw new ValidationException($this->validator);
}

Type Casting

You can easily cast your DTO properties by defining a casts method in your DTO:

/**
 * Defines the type casting for the properties of the DTO.
 *
 * @return array
 */
protected function casts(): array
{
    return [
        'name' => new StringCast(),
        'age'  => new IntegerCast(),
        'created_at' => new CarbonImmutableCast(),
    ];
}

Available Types

Array

For JSON strings, it will convert into an array, for other types, it will wrap them in an array.

protected function casts(): array
{
    return [
        'property' => new ArrayCast(),
    ];
}

Boolean

For string values, this uses the filter_var function with the FILTER_VALIDATE_BOOLEAN flag.

protected function casts(): array
{
    return [
        'property' => new BooleanCast(),
    ];
}

Carbon

This accepts any value accepted by the Carbon constructor. If an invalid value is found it will throw a \WendellAdriel\ValidatedDTO\Exceptions\CastException exception.

protected function casts(): array
{
    return [
        'property' => new CarbonCast(),
    ];
}

You can also pass a timezone when defining the cast if you need that will be used when casting the value.

protected function casts(): array
{
    return [
        'property' => new CarbonCast('Europe/Lisbon'),
    ];
}

You can also pass a format when defining the cast to be used to cast the value. If the property has a different format than the specified it will throw a \WendellAdriel\ValidatedDTO\Exceptions\CastException exception.

protected function casts(): array
{
    return [
        'property' => new CarbonCast('Europe/Lisbon', 'Y-m-d'),
    ];
}

CarbonImmutable

This accepts any value accepted by the CarbonImmutable constructor. If an invalid value is found it will throw a \WendellAdriel\ValidatedDTO\Exceptions\CastException exception.

protected function casts(): array
{
    return [
        'property' => new CarbonImmutableCast(),
    ];
}

You can also pass a timezone when defining the cast if you need that will be used when casting the value.

protected function casts(): array
{
    return [
        'property' => new CarbonImmutableCast('Europe/Lisbon'),
    ];
}

protected function casts(): array
{
    return [
        'property' => new CarbonImmutableCast('Europe/Lisbon', 'Y-m-d'),
    ];
}

Collection

For JSON strings, it will convert into an array first, before wrapping it into a Collection object.

protected function casts(): array
{
    return [
        'property' => new CollectionCast(),
    ];
}

If you want to cast all the elements inside the Collection, you can pass a Castable to the CollectionCast constructor. Let's say that you want to convert all the items inside the Collection into integers:

protected function casts(): array
{
    return [
        'property' => new CollectionCast(new IntegerCast()),
    ];
}

This works with all Castable, including DTOCast and ModelCast for nested data.

DTO

This works with arrays and JSON strings. This will validate the data and also cast the data for the given DTO.

This will throw a Illuminate\Validation\ValidationException exception if the data is not valid for the DTO.

This will throw a WendellAdriel\ValidatedDTO\Exceptions\CastException exception if the property is not a valid array or valid JSON string.

This will throw a WendellAdriel\ValidatedDTO\Exceptions\CastTargetException exception if the class passed to the DTOCast constructor is not a ValidatedDTO instance.

protected function casts(): array
{
    return [
        'property' => new DTOCast(UserDTO::class),
    ];
}

Float

If a not numeric value is found, it will throw a WendellAdriel\ValidatedDTO\Exceptions\CastException exception.

protected function casts(): array
{
    return [
        'property' => new FloatCast(),
    ];
}

Integer

If a not numeric value is found, it will throw a WendellAdriel\ValidatedDTO\Exceptions\CastException exception.

protected function casts(): array
{
    return [
        'property' => new IntegerCast(),
    ];
}

Model

This works with arrays and JSON strings.

This will throw a WendellAdriel\ValidatedDTO\Exceptions\CastException exception if the property is not a valid array or valid JSON string.

This will throw a WendellAdriel\ValidatedDTO\Exceptions\CastTargetException exception if the class passed to the ModelCast constructor is not a Model instance.

protected function casts(): array
{
    return [
        'property' => new ModelCast(User::class),
    ];
}

Object

This works with arrays and JSON strings.

This will throw a WendellAdriel\ValidatedDTO\Exceptions\CastException exception if the property is not a valid array or valid JSON string.

protected function casts(): array
{
    return [
        'property' => new ObjectCast(),
    ];
}

String

If the data can't be converted into a string, this will throw a WendellAdriel\ValidatedDTO\Exceptions\CastException exception.

protected function casts(): array
{
    return [
        'property' => new StringCast(),
    ];
}

Create Your Own Type Cast

Castable classes

You can easily create new Castable types for your project by implementing the WendellAdriel\ValidatedDTO\Casting\Castable interface. This interface has a single method that must be implemented:

/**
 * Casts the given value.
 *
 * @param  string  $property
 * @param  mixed  $value
 * @return mixed
 */
public function cast(string $property, mixed $value): mixed;

Let's say that you have a URLWrapper class in your project, and you want that when passing a URL into your DTO it will always return a URLWrapper instance instead of a simple string:

class URLCast implements Castable
{
    /**
     * @param  string  $property
     * @param  mixed  $value
     * @return URLWrapper
     */
    public function cast(string $property, mixed $value): URLWrapper
    {
        return new URLWrapper($value);
    }
}

Then you could apply this to your DTO:

class CustomDTO extends ValidatedDTO
{
    protected function rules(): array
    {
        return [
            'url' => ['required', 'url'],
        ];
    }

    protected function defaults(): array
    {
        return [];
    }

    protected function casts(): array
    {
        return [
            'url' => new URLCast(),
        ];
    }
}

Callable Casts

You can also create new Castable types for your project by using a callable/callback:

class CustomDTO extends ValidatedDTO
{
    protected function rules(): array
    {
        return [
            'url' => ['required', 'url'],
        ];
    }

    protected function defaults(): array
    {
        return [];
    }

    protected function casts(): array
    {
        return [
            'url' => function (string $property, mixed $value) {
                return new URLWrapper($value);
            },
        ];
    }
}

Casting Eloquent Model properties to DTOs

You can easily cast any Eloquent Model properties to your DTOs:

class MyModel extends Model
{
    protected $fillable = ['name', 'metadata'];

    protected $casts = [
        'metadata' => AttributesDTO::class,
    ];
}

The DTO class:

class AttributesDTO extends ValidatedDTO
{
    public int $age;

    public string $doc;

    protected function rules(): array
    {
        return [
            'age' => ['required', 'integer'],
            'doc' => ['required', 'string'],
        ];
    }

    protected function defaults(): array
    {
        return [];
    }

    protected function casts(): array
    {
        return [
            'age' => new IntegerCast(),
            'doc' => new StringCast(),
        ];
    }
}

More DTOs

Simple DTOs

If you don't need to validate the data, you can use the SimpleDTO class instead of the ValidatedDTO class. The DTOs created with this class will not validate the data, but will still have all the other features of the ValidatedDTO class:

class SimpleUserDTO extends SimpleDTO
{
    public string $name;

    public string $email;

    public int $age;

    protected function defaults(): array
    {
        return [];
    }

    protected function casts(): array
    {
        return [
            'name' => new StringCast(),
            'email' => new StringCast(),
            'age' => new IntegerCast(),
        ];
    }

    protected function mapBeforeValidation(): array
    {
        return [
            'username' => 'name',
            'user_email' => 'email',
        ];
    }

    protected function mapBeforeExport(): array
    {
        return [
            'name' => 'customer_name',
            'email' => 'customer_email',
        ];
    }
}

To generate a SimpleDTO you can use the --simple flag:

php artisan make:dto SimpleUserDTO --simple

Resource DTOs

If you want to use DTOs to wrap, type and transform your API responses, you can use the ResourceDTO class. This class will have the same features as the SimpleDTO class and will implement the Illuminate\Contracts\Support\Responsable interface:

class UserResourceDTO extends ResourceDTO
{
    public string $name;

    public string $email;

    public int $age;

    // Your DTO methods...
}

Then you can return your DTOs from your controllers:

class UserController extends Controller
{
    public function show(int $id)
    {
        return UserResourceDTO::fromModel(User::findOrFail($id));
    }
}

You can also return a collection/list of your DTOs as a response using the ResourceDTO::collection() method:

class UserController extends Controller
{
    public function index()
    {
        return UserResourceDTO::collection(User::all());
    }
}

This way every item in the collection will be converted to a UserResourceDTO instance before sending the response to the client, using all the typing, casting and mapping features of your DTO class.

To generate a ResourceDTO you can use the --resource flag:

php artisan make:dto UserResourceDTO --resource

Wireable DTOS

If you're using Laravel Livewire, you can turn your DTOs into wireable DTOs by adding the WendellAdriel\ValidatedDTO\Concerns\Wireable trait to your DTOs:

class UserDTO extends ValidatedDTO
{
    use Wireable;

    // Your DTO code...
}

Credits

Contributing

Check the Contributing Guide.

WendellAdriel/laravel-validated-dto

WendellAdriel

Reviews

Repository Details

Laravel Validated DTO

Documentation

Features

Installation

Configuration

Why use this package

Generating DTOs

Defining DTO Properties

Defining Validation Rules

Creating DTO instances

From arrays

From JSON strings

From Request objects

From Eloquent Models

From Artisan Commands

From the Command Arguments

From the Command Options

From the Command Arguments and Options

Accessing DTO data

Defining Default Values

Converting DTO data

To array

To JSON string

To Eloquent Model

Mapping DTO properties

Mapping data before validation

Mapping nested data to flat data

Mapping data before export

Mapping nested data to flat data

Customizing Error Messages, Attributes and Exceptions

Type Casting

Available Types

Array

Boolean

Carbon

CarbonImmutable

Collection

DTO

Float

Integer

Model

Object

String

Create Your Own Type Cast

Castable classes

Callable Casts

Casting Eloquent Model properties to DTOs

More DTOs

Simple DTOs

Resource DTOs

Wireable DTOS

Credits

Contributing

More Repositories