Praktické příklady

1# stav po odeslání objednávky, když neběží workery2order            confirmed  (saga_in_progress = 1)3order_dashboard  0 řádků4reporting_orders 0 řádků5outbox           1 řádek ve stavu pending

1php bin/console app:outbox:dispatch --time-limit=36002php bin/console messenger:consume async_events async_commands --time-limit=3600

1src/2├── Cart/                      # Bounded Context: Košík3│   ├── Domain/4│   │   ├── Model/Cart.php          # Aggregate Root5│   │   ├── Model/CartItem.php6│   │   ├── ValueObject/CartId.php, ProductId.php, UserId.php7│   │   ├── Event/ItemAddedToCart.php, CartCheckedOut.php, CheckedOutItem.php8│   │   ├── Exception/EmptyCartException.php, CartAlreadyCheckedOutException.php9│   │   └── Repository/CartRepository.php10│   ├── Infrastructure/Repository/DoctrineCartRepository.php11│   ├── AddItem/{Command, Controller}/  # Feature slice12│   ├── GetCart/{Query, ViewModel}/     # Feature slice13│   └── Checkout/Controller/             # Feature slice14├── Ordering/                  # Bounded Context: Objednávky (vrstvy)15│   ├── Domain/Model/Order.php          # Aggregate Root16│   ├── Domain/ValueObject/OrderId.php, CustomerId.php, ProductId.php17│   ├── Domain/Event/OrderPlaced.php18│   ├── Application/Command/PlaceOrder.php19│   ├── Application/Handler/PlaceOrderHandler.php20│   ├── Application/Listener/PlaceOrderOnCartCheckedOut.php21│   └── Infrastructure/Http/PlaceOrderController.php22└── SharedKernel/Domain/{Money.php, 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    private bool $checkedOut = false;8 9    public static function open(CartId $id, UserId $userId): self { /* ... */ }10 11    public function addItem(ProductId $productId, int $quantity, Money $unitPrice): void12    {13        // INVARIANT: jedna položka na produkt – množství se sčítá, řádek se neduplikuje.14        $existing = $this->findItem($productId);15 16        if ($existing !== null) {17            $existing->increaseQuantity($quantity);18        } else {19            $this->items->add(new CartItem($this->id, $productId, $quantity, $unitPrice));20        }21 22        $this->record(new ItemAddedToCart($this->id, $productId, $quantity));23    }24 25    public function checkout(): void26    {27        // INVARIANT: z prázdného košíku objednávka nevznikne.28        if ($this->items->isEmpty()) {29            throw EmptyCartException::withId($this->id);30        }31 32        // INVARIANT: košík se odbaví jednou. Bez toho by dvojklik nebo33        // retry vyrobil dvě události, a tím dvě objednávky.34        if ($this->checkedOut) {35            throw CartAlreadyCheckedOutException::withId($this->id);36        }37 38        $this->checkedOut = true;39 40        $this->record(new CartCheckedOut(41            $this->id,42            $this->userId,43            array_map(CheckedOutItem::fromCartItem(...), $this->items->toArray()),44            new \DateTimeImmutable(),45        ));46    }47 48    public function removeItem(ProductId $productId): void { /* ... */ }49    public function totalAmount(): Money { /* sumace přes items */ }50    private function findItem(ProductId $productId): ?CartItem { /* ... */ }51}

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

1<?php2 3declare(strict_types=1);4 5namespace App\Cart\Domain\Event;6 7use App\Cart\Domain\ValueObject\CartId;8use App\Cart\Domain\ValueObject\UserId;9 10final readonly class CartCheckedOut11{12    /** @param list<CheckedOutItem> $items */13    public function __construct(14        public CartId $cartId,15        public UserId $userId,16        public array $items,17        public \DateTimeImmutable $occurredAt,18    ) {}19}

1<?php2 3declare(strict_types=1);4 5namespace App\Ordering\Application\Listener;6 7use App\Cart\Domain\Event\CartCheckedOut;8use App\Cart\Domain\Event\CheckedOutItem;9use App\Ordering\Application\Command\PlaceOrder;10use Symfony\Component\DependencyInjection\Attribute\Target;11use Symfony\Component\Messenger\Attribute\AsMessageHandler;12use Symfony\Component\Messenger\MessageBusInterface;13 14#[AsMessageHandler(bus: 'event.bus')]15final readonly class PlaceOrderOnCartCheckedOut16{17    public function __construct(18        #[Target('command.bus')]19        private MessageBusInterface $commandBus,20    ) {}21 22    public function __invoke(CartCheckedOut $event): void23    {24        // Listener sám nic neukládá. event.bus nemá doctrine_transaction,25        // takže save() bez flushe by nic nezapsal a OrderPlaced by nikdo26        // nevyzvedl. Transakci, potvrzení i outbox obstará handler commandu.27        $this->commandBus->dispatch(new PlaceOrder(28            customerId: $event->userId->value,29            items: array_map(30                static fn (CheckedOutItem $item): array => [31                    'productId' => $item->productId->value,32                    'quantity' => $item->quantity,33                    'unitPriceInCents' => $item->unitPrice->amountInCents,34                ],35                $event->items,36            ),37        ));38    }39}

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    │   ├── Exception/CommentsClosedException.php, InvalidPostTitleException.php,9    │   │   EmptyPostContentException.php10    │   └── Repository/PostRepository.php11    ├── Infrastructure/Repository/DoctrinePostRepository.php12    ├── CreatePost/{Command, Controller}/13    ├── AddComment/{Command, Controller}/14    ├── GetPost/{Query, Controller, ViewModel}/15    └── GetPosts/{Query, Controller, ViewModel}/

1final class Post extends AggregateRoot2{3    /** @var Collection<int, Comment> */4    private Collection $comments;5    private bool $commentsClosed = false;6 7    private function __construct(8        public readonly PostId $id,9        private string $title,10        private string $content,11        public readonly AuthorId $authorId,12        public readonly \DateTimeImmutable $createdAt,13    ) {14        $this->comments = new ArrayCollection();15    }16 17    public static function create(PostId $id, string $title, string $content, AuthorId $authorId): self18    {19        // INVARIANT: titulek má 3–255 znaků a obsah není prázdný.20        $titleLength = mb_strlen($title);21        if ($titleLength < 3 || $titleLength > 255) {22            throw InvalidPostTitleException::lengthOutOfRange($titleLength);23        }24        if (trim($content) === '') {25            throw EmptyPostContentException::forPost($id);26        }27 28        $post = new self($id, $title, $content, $authorId, new \DateTimeImmutable());29        $post->record(new PostCreated($id, $title, $authorId));30 31        return $post;32    }33 34    public function addComment(CommentId $id, AuthorId $authorId, string $text): void35    {36        // INVARIANT: do uzavřené diskuse komentář nepřibude.37        if ($this->commentsClosed) {38            throw CommentsClosedException::forPost($this->id);39        }40 41        $this->comments->add(new Comment($id, $this->id, $authorId, $text));42        $this->record(new CommentAdded($this->id, $id, $authorId));43    }44 45    public function closeComments(): void { /* ... */ }46    public function updateTitle(string $newTitle): void { /* ... */ }47    public function updateContent(string $newContent): void { /* ... */ }48}

1#[AsMessageHandler(bus: 'command.bus')]2final readonly class CreatePostHandler3{4    public function __construct(private PostRepository $posts) {}5 6    public function __invoke(CreatePost $command): void7    {8        $post = Post::create(9            new PostId($command->postId),10            $command->title,11            $command->content,12            new AuthorId($command->authorId),13        );14 15        $this->posts->save($post);16    }17}

1src/2└── UserManagement/            # Bounded Context: Správa uživatelů3    ├── Domain/4    │   ├── Model/User.php           # Aggregate Root5    │   ├── ValueObject/UserId.php, Email.php, HashedPassword.php6    │   ├── Event/UserRegistered.php7    │   ├── Exception/DuplicateEmailException.php8    │   └── Repository/UserRepository.php9    ├── Infrastructure/Repository/DoctrineUserRepository.php10    ├── Registration/{Command, Controller}/11    ├── Authentication/Controller/12    └── Profile/{Query, Controller}/

1final class User extends AggregateRoot implements UserInterface, PasswordAuthenticatedUserInterface2{3    private function __construct(4        public readonly UserId $id,5        private UserName $name,6        private Email $email,7        private HashedPassword $hashedPassword,8        public readonly \DateTimeImmutable $createdAt,9    ) {10    }11 12    public static function register(UserId $id, UserName $name, Email $email, HashedPassword $hashedPassword): self13    {14        $user = new self($id, $name, $email, $hashedPassword, 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 rename(UserName $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->hashedPassword->value; }27}

1#[AsMessageHandler(bus: 'command.bus')]2final readonly class RegisterUserHandler3{4    public function __construct(5        private UserRepository $users,6        private EntityManagerInterface $em,7    ) {}8 9    public function __invoke(RegisterUser $command): void10    {11        // Normalizace vstupu (trim, lowercase) patří do fromUserInput(),12        // konstruktor Email jen validuje.13        $email = Email::fromUserInput($command->email);14 15        $user = User::register(16            UserId::generate(),17            new UserName($command->name),18            $email,19            HashedPassword::fromPlainText($command->password),20        );21 22        try {23            $this->users->save($user);24            // Flush ručně: unique constraint se vyhodnotí až zde a překlad25            // na doménovou výjimku musí proběhnout uvnitř try bloku.26            $this->em->flush();27        } catch (UniqueConstraintViolationException $e) {28            throw DuplicateEmailException::with($email, $e);29        }30    }31}