Symfony Dto Bundle Laravel Package

Getting Started

Minimal Setup

1. Installation:

   composer require bigyohann/symfony-dto-bundle
   

   Add to config/bundles.php:

   return [
       // ...
       Bigyohann\DtoBundle\BigyohannDtoBundle::class => ['all' => true],
   ];
   

2. First DTO Class: Extend Bigyohann\DtoBundle\Dto\Dto and define private properties with getters:

   use Bigyohann\DtoBundle\Dto\Dto;
   
   class UserDto extends Dto {
       private ?string $name;
   
       public function getName(): ?string { return $this->name; }
   }
   

3. First Use Case: Convert an array to DTO in a controller:

   use Bigyohann\DtoBundle\Dto\Dto;
   
   public function show(Request $request, Dto $dto): Response {
       $userData = ['name' => 'John'];
       $userDto = $dto->convert($userData); // Auto-maps properties
       return new Response($userDto->getName());
   }
   

Implementation Patterns

Core Workflow

1. DTO Design:

   • Extend Dto for auto-conversion or DtoInterface for manual control.
   • Use #[ConvertProperty] to opt-in/out of auto-mapping.
   • Example:

     #[ConvertProperty(shouldConvertAutomatically: false)]
     private ?int $id;
     

2. Controller Integration:

   • Inject Dto service (auto-registered) or create custom DTOs.
   • Convert request data:

     $dto = $this->dtoConverter->convert($request->all(), UserDto::class);
     

3. Validation: Leverage Symfony’s constraints (e.g., #[Type], #[Length]) directly on DTO properties.

4. Service Layer: Use DTOs for API responses or form handling:

   public function getUser(User $user): UserDto {
       return (new UserDto())->convert($user->toArray());
   }
   

Advanced Patterns

• Nested DTOs: Auto-conversion works recursively if nested objects are DTOs.
• Partial Updates: Use convert() with a subset of properties:

  $dto->convert(['name' => 'Jane']); // Only updates `name`
  

• Custom Mappers: Override convert() for complex logic:

  public function convert(array $data): self {
      $this->name = strtoupper($data['name'] ?? '');
      return $this;
  }
  

Gotchas and Tips

Pitfalls

1. Property Visibility:

   • Properties must be private for auto-conversion to work.
   • Getters must exist (no magic methods).

2. Attribute Conflicts:

   • #[ConvertProperty] overrides default behavior. Omit it to disable auto-conversion for a property.

3. Circular References:

   • Auto-conversion fails if DTOs reference each other circularly (e.g., UserDto has AddressDto, which has UserDto).

4. Type Safety:

   • The bundle doesn’t enforce type hints in convert(). Validate manually or use Symfony’s #[Type] constraint.

Debugging

• Missing Properties: Check for typos in property names or missing getters.
• Auto-Conversion Issues: Enable debug mode and inspect the convert() method’s input/output.
• Bundle Not Loaded: Verify BigyohannDtoBundle is in config/bundles.php and composer.json autoloads the Bigyohann\DtoBundle namespace.

Tips

1. Exclude Sensitive Data: Use shouldConvertAutomatically: false for passwords or tokens:

   #[ConvertProperty(shouldConvertAutomatically: false)]
   private ?string $apiToken;
   

2. Custom Conversion Logic: Extend Dto and override convert():

   public function convert(array $data): self {
       $data['name'] = ucfirst($data['name']);
       return parent::convert($data);
   }
   

3. Performance: Reuse DTO instances instead of creating new ones:

   $dto = new UserDto();
   $dto->convert($data); // Reuse instead of `new UserDto()->convert($data)`
   

4. Testing: Mock Dto in tests to isolate logic:

   $dto = $this->createMock(Dto::class);
   $dto->method('convert')->willReturn($dto);