Use Case Generator

Generate Application-layer Use Cases that orchestrate domain operations.

Use Case Characteristics

• Single responsibility: One operation per use case
• Orchestration: Coordinates domain objects
• Transaction boundary: Manages atomicity
• Event dispatch: Publishes domain events
• No business logic: Delegates to domain
• Framework agnostic: No HTTP/CLI concerns

When to Use

Scenario	Example
Create operation	CreateOrderUseCase
State transition	ConfirmOrderUseCase
External service integration	ProcessPaymentUseCase
Multi-step workflow	CheckoutUseCase

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Generation Process

Step 1: Generate Use Case

Path: src/Application/{BoundedContext}/UseCase/

1. {Name}UseCase.php — Main orchestration class

Step 2: Generate Input DTO

Path: src/Application/{BoundedContext}/DTO/

1. {Name}Input.php — Input data container

Step 3: Generate Output DTO

Path: src/Application/{BoundedContext}/DTO/

1. {Name}Output.php — Result data container

Step 4: Generate Tests

Path: tests/Unit/Application/{BoundedContext}/UseCase/

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File Placement

Component	Path
Use Case	src/Application/{BoundedContext}/UseCase/
Input DTO	src/Application/{BoundedContext}/DTO/
Output DTO	src/Application/{BoundedContext}/DTO/
Unit Tests	tests/Unit/Application/{BoundedContext}/UseCase/

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Naming Conventions

Pattern	Example
Use Case	{Verb}{Entity}UseCase
Input DTO	{Name}Input
Output DTO	{Name}Output or {Entity}{Result}Output

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Quick Template Reference

Use Case

final readonly class {Name}UseCase
{
    public function __construct(
        private {Repository}Interface $repository,
        private EventDispatcherInterface $events,
        private TransactionManagerInterface $transaction
    ) {}

    public function execute({Name}Input $input): {Name}Output
    {
        return $this->transaction->transactional(function () use ($input) {
            $aggregate = $this->repository->findById($input->id);
            $aggregate->doSomething($input->data);
            $this->repository->save($aggregate);

            foreach ($aggregate->releaseEvents() as $event) {
                $this->events->dispatch($event);
            }

            return new {Name}Output(...);
        });
    }
}

Input DTO

final readonly class {Name}Input
{
    public function __construct(
        public {ValueObject} $id,
        {additionalProperties}
    ) {}
}

Output DTO

final readonly class {Name}Output
{
    public function __construct(
        public string $id,
        {resultProperties}
    ) {}

    public function toArray(): array
    {
        return ['id' => $this->id, ...];
    }
}

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Anti-patterns to Avoid

Anti-pattern	Problem	Solution
Business Logic	Decisions in use case	Delegate to domain
Multiple Aggregates	Transaction spans aggregates	One aggregate per transaction
Direct Repo Calls	Bypassing use case	Always use use case
Missing Transaction	No atomicity	Wrap in transaction
External in Transaction	Long-running transactions	External calls outside

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References

For complete PHP templates and examples, see:

• references/templates.md — UseCase, Input, Output, Test templates with design principles
• references/examples.md — CreateOrder, ConfirmOrder, ProcessPayment examples and tests