Praktické příklady

1src/2├── Cart/                      # Bounded Context: Košík3│   ├── Domain/4│   │   ├── Model/Cart.php          # Aggregate Root5│   │   ├── Model/CartItem.php6│   │   ├── ValueObject/CartId.php, ProductId.php, Quantity.php, Money.php7│   │   ├── Event/ItemAddedToCart.php, CartCheckedOut.php8│   │   └── Repository/CartRepository.php9│   ├── Infrastructure/Repository/DoctrineCartRepository.php10│   ├── AddItem/{Command, Controller}/  # Feature slice11│   ├── GetCart/{Query, ViewModel}/     # Feature slice12│   └── Checkout/Controller/             # Feature slice13├── Order/                     # Bounded Context: Objednávky14│   ├── Domain/Model/Order.php          # Aggregate Root15│   ├── Domain/Event/OrderCreated.php16│   └── CreateOrder/{Command, Controller}/17└── Shared/Domain/Exception/DomainException.php

1final class Cart extends AggregateRoot2{3    public readonly CartId $id;4    public readonly UserId $userId;5    /** @var Collection<int, CartItem> */6    private Collection $items;7 8    public static function open(CartId $id, UserId $userId): self { /* ... */ }9 10    public function addItem(ProductId $productId, Quantity $quantity, Money $price): void11    {12        // Invariant: pokud productId existuje, zvyš quantity; jinak přidej nový item.13        // Vyemituje ItemAddedToCart event.14    }15 16    public function removeItem(ProductId $productId): void { /* ... */ }17    public function totalAmount(): Money { /* sumace přes items */ }18    public function checkout(): void { /* invariant: cart nesmí být prázdný */ }19}

1#[AsMessageHandler]2final class AddItemToCartHandler3{4    public function __construct(5        private CartRepository $cartRepository,6        private ProductRepository $productRepository,7    ) {}8 9    public function __invoke(AddItemToCart $command): void10    {11        $cart = $this->cartRepository->findByIdOrFail(new CartId($command->cartId));12        $product = $this->productRepository->findByIdOrFail(new ProductId($command->productId));13 14        $cart->addItem($product->id(), new Quantity($command->quantity), $product->price());15 16        $this->cartRepository->save($cart);17    }18}

1src/2└── Blog/                      # Bounded Context: Blog3    ├── Domain/4    │   ├── Model/Post.php           # Aggregate Root5    │   ├── Model/Comment.php6    │   ├── ValueObject/PostId.php, CommentId.php, AuthorId.php7    │   ├── Event/PostCreated.php, CommentAdded.php8    │   └── Repository/PostRepository.php9    ├── Infrastructure/Repository/DoctrinePostRepository.php10    ├── CreatePost/{Command, Controller}/11    ├── GetPost/{Query, Controller, ViewModel}/12    └── GetPosts/{Query, Controller, ViewModel}/

1final class Post extends AggregateRoot2{3    private function __construct(4        public readonly PostId $id,5        private string $title,6        private string $content,7        public readonly AuthorId $authorId,8        public readonly \DateTimeImmutable $createdAt,9    ) {10        $this->record(new PostCreated($id, $title, $authorId));11    }12 13    public static function create(PostId $id, string $title, string $content, AuthorId $authorId): self14    {15        // Invarianty: title 3–255 znaků, content nesmí být prázdný16        return new self($id, $title, $content, $authorId, new \DateTimeImmutable());17    }18 19    public function updateTitle(string $newTitle): void { /* ... */ }20    public function updateContent(string $newContent): void { /* ... */ }21}

1#[AsMessageHandler]2final class CreatePostHandler3{4    public function __construct(private PostRepository $posts) {}5 6    public function __invoke(CreatePost $command): string7    {8        $post = Post::create(9            PostId::generate(),10            $command->title,11            $command->content,12            new AuthorId($command->authorId),13        );14 15        $this->posts->save($post);16 17        return $post->id->value;18    }19}

1src/2└── UserManagement/            # Bounded Context: Správa uživatelů3    ├── Domain/4    │   ├── Model/User.php           # Aggregate Root5    │   ├── ValueObject/UserId.php, Email.php, HashedPassword.php6    │   ├── Event/UserRegistered.php7    │   └── Repository/UserRepository.php8    ├── Infrastructure/Repository/DoctrineUserRepository.php9    ├── Registration/{RegisterUser, RegisterUserHandler, RegistrationController}.php10    ├── Authentication/SecurityController.php11    └── Profile/{GetUserProfile, GetUserProfileHandler, ProfileController}.php

1final class User extends AggregateRoot implements UserInterface, PasswordAuthenticatedUserInterface2{3    private function __construct(4        public readonly UserId $id,5        private string $name,6        private Email $email,7        private HashedPassword $password,8        public readonly \DateTimeImmutable $createdAt,9    ) {10    }11 12    public static function register(UserId $id, string $name, Email $email, HashedPassword $password): self13    {14        $user = new self($id, $name, $email, $password, new \DateTimeImmutable());15        $user->record(new UserRegistered($id, $email, $user->createdAt));16 17        return $user;18    }19 20    public function changeEmail(Email $newEmail): void { /* invariant: nový != starý */ }21    public function changeName(string $newName): void { /* ... */ }22 23    // UserInterface – eraseCredentials() Symfony 8 z rozhraní odstranilo24    public function getRoles(): array { return ['ROLE_USER']; }25    public function getUserIdentifier(): string { return $this->email->value; }26    public function getPassword(): ?string { return $this->password->hash; }27}

1#[AsMessageHandler]2final class RegisterUserHandler3{4    public function __construct(5        private UserRepository $users,6        private UserPasswordHasherInterface $passwordHasher,7    ) {}8 9    public function __invoke(RegisterUser $command): void10    {11        $email = new Email($command->email);12 13        // Invariant na úrovni handleru: email musí být unikátní (DB unique constraint14        // je pojistka pro race condition, viz /implementace-v-symfony#register-race-heading).15        if ($this->users->findByEmail($email) !== null) {16            throw DuplicateEmailException::with($email);17        }18 19        $user = User::register(20            UserId::generate(),21            $command->name,22            $email,23            HashedPassword::fromHasher($this->passwordHasher, $command->password),24        );25 26        $this->users->save($user);27    }28}