platform/docs/contracts_package_specification.md
2024-11-12 01:00:05 -07:00

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# Contracts Package Specification
## Overview
The Contracts package defines the core interfaces and contracts that form the foundation of the framework. These contracts ensure consistency and interoperability between components while enabling loose coupling and dependency injection.
> **Related Documentation**
> - See [Laravel Compatibility Roadmap](laravel_compatibility_roadmap.md) for implementation status
> - See [Foundation Integration Guide](foundation_integration_guide.md) for integration patterns
> - See [Testing Guide](testing_guide.md) for testing approaches
> - See [Getting Started Guide](getting_started.md) for development setup
## Core Contracts
### 1. Container Contracts
```dart
/// Core container interface
abstract class ContainerContract {
/// Resolves a type from the container
T make<T>([dynamic context]);
/// Binds a type to the container
void bind<T>(T Function(ContainerContract) concrete);
/// Binds a singleton to the container
void singleton<T>(T Function(ContainerContract) concrete);
/// Checks if a type is bound
bool has<T>();
/// Tags implementations for grouped resolution
void tag(List<Type> implementations, String tag);
/// Gets all implementations with a tag
List<T> tagged<T>(String tag);
/// Adds a contextual binding
void addContextualBinding(Type concrete, Type abstract, dynamic implementation);
/// Creates a new child container
ContainerContract createChild();
}
/// Interface for contextual binding
abstract class ContextualBindingBuilder {
/// Specifies the type needed in this context
ContextualNeedsBuilder needs<T>();
}
/// Interface for contextual needs
abstract class ContextualNeedsBuilder {
/// Specifies what to give for this need
void give(dynamic implementation);
}
/// Interface for service providers
abstract class ServiceProviderContract {
/// Registers services with the container
void register();
/// Bootstraps any services
Future<void> boot();
/// Gets provided services
List<Type> provides();
/// Whether provider is deferred
bool get isDeferred => false;
}
```
### 2. Event Contracts
```dart
/// Core event dispatcher interface
abstract class EventDispatcherContract {
/// Registers an event listener
void listen<T>(void Function(T event) listener);
/// Dispatches an event
Future<void> dispatch<T>(T event);
/// Registers an event subscriber
void subscribe(EventSubscriber subscriber);
/// Dispatches an event after database commit
Future<void> dispatchAfterCommit<T>(T event);
/// Gets registered listeners
List<Function> getListeners(Type event);
}
/// Interface for event subscribers
abstract class EventSubscriber {
/// Gets events to subscribe to
Map<Type, Function> subscribe();
}
/// Interface for queueable events
abstract class ShouldQueue {
/// Gets the queue to use
String get queue => 'default';
/// Gets the delay before processing
Duration? get delay => null;
/// Gets the number of tries
int get tries => 1;
}
/// Interface for broadcastable events
abstract class ShouldBroadcast {
/// Gets channels to broadcast on
List<String> broadcastOn();
/// Gets event name for broadcasting
String broadcastAs() => runtimeType.toString();
/// Gets broadcast data
Map<String, dynamic> get broadcastWith => {};
}
```
### 3. Queue Contracts
```dart
/// Core queue interface
abstract class QueueContract {
/// Pushes a job onto the queue
Future<String> push(dynamic job, [String? queue]);
/// Pushes a job with delay
Future<String> later(Duration delay, dynamic job, [String? queue]);
/// Gets next job from queue
Future<Job?> pop([String? queue]);
/// Creates a job batch
Batch batch(List<Job> jobs);
/// Gets a queue connection
QueueConnection connection([String? name]);
}
/// Interface for queue jobs
abstract class Job {
/// Unique job ID
String get id;
/// Job payload
Map<String, dynamic> get payload;
/// Number of attempts
int get attempts;
/// Maximum tries
int get tries => 1;
/// Timeout in seconds
int get timeout => 60;
/// Executes the job
Future<void> handle();
/// Handles job failure
Future<void> failed([Exception? exception]);
}
/// Interface for job batches
abstract class Batch {
/// Batch ID
String get id;
/// Jobs in batch
List<Job> get jobs;
/// Adds jobs to batch
void add(List<Job> jobs);
/// Dispatches the batch
Future<void> dispatch();
}
```
### 4. Bus Contracts
```dart
/// Core command bus interface
abstract class CommandBusContract {
/// Dispatches a command
Future<dynamic> dispatch(Command command);
/// Dispatches a command now
Future<dynamic> dispatchNow(Command command);
/// Dispatches a command to queue
Future<dynamic> dispatchToQueue(Command command);
/// Creates a command batch
PendingBatch batch(List<Command> commands);
/// Creates a command chain
PendingChain chain(List<Command> commands);
}
/// Interface for commands
abstract class Command {
/// Gets command handler
Type get handler;
}
/// Interface for command handlers
abstract class Handler<T extends Command> {
/// Handles the command
Future<dynamic> handle(T command);
}
/// Interface for command batches
abstract class PendingBatch {
/// Dispatches the batch
Future<void> dispatch();
/// Allows failures
PendingBatch allowFailures();
}
```
### 5. Pipeline Contracts
```dart
/// Core pipeline interface
abstract class PipelineContract<T> {
/// Sends value through pipeline
PipelineContract<T> send(T passable);
/// Sets the pipes
PipelineContract<T> through(List<PipeContract<T>> pipes);
/// Processes the pipeline
Future<R> then<R>(Future<R> Function(T) destination);
}
/// Interface for pipes
abstract class PipeContract<T> {
/// Handles the passable
Future<dynamic> handle(T passable, Function next);
}
/// Interface for pipeline hub
abstract class PipelineHubContract {
/// Gets a pipeline
PipelineContract<T> pipeline<T>(String name);
/// Sets default pipes
void defaults(List<PipeContract> pipes);
}
```
## Usage Examples
### Container Usage
```dart
// Register service provider
class AppServiceProvider implements ServiceProviderContract {
@override
void register() {
container.bind<UserService>((c) => UserService(
c.make<DatabaseConnection>(),
c.make<CacheContract>()
));
}
@override
Future<void> boot() async {
// Bootstrap services
}
}
```
### Event Handling
```dart
// Define event
class OrderShipped implements ShouldQueue, ShouldBroadcast {
final Order order;
@override
List<String> broadcastOn() => ['orders.${order.id}'];
@override
String get queue => 'notifications';
}
// Handle event
dispatcher.listen<OrderShipped>((event) async {
await notifyCustomer(event.order);
});
```
### Command Bus Usage
```dart
// Define command
class CreateOrder implements Command {
final String customerId;
final List<String> products;
@override
Type get handler => CreateOrderHandler;
}
// Handle command
class CreateOrderHandler implements Handler<CreateOrder> {
@override
Future<Order> handle(CreateOrder command) async {
// Create order
}
}
// Dispatch command
var order = await bus.dispatch(CreateOrder(
customerId: '123',
products: ['abc', 'xyz']
));
```
## Testing
```dart
void main() {
group('Event Dispatcher', () {
test('dispatches after commit', () async {
var dispatcher = MockEventDispatcher();
var db = MockDatabase();
await db.transaction((tx) async {
await dispatcher.dispatchAfterCommit(OrderShipped(order));
});
verify(() => dispatcher.dispatch(any())).called(1);
});
});
group('Command Bus', () {
test('handles command batch', () async {
var bus = MockCommandBus();
await bus.batch([
CreateOrder(...),
UpdateInventory(...)
]).dispatch();
verify(() => bus.dispatchNow(any())).called(2);
});
});
}
```
## Contract Guidelines
1. **Keep Contracts Minimal**
```dart
// Good: Focused contract
abstract class Cache {
Future<T?> get<T>(String key);
Future<void> put<T>(String key, T value);
}
// Bad: Too many responsibilities
abstract class Cache {
Future<T?> get<T>(String key);
Future<void> put<T>(String key, T value);
void clearMemory();
void optimizeStorage();
void defragment();
}
```
2. **Use Type Parameters**
```dart
// Good: Type safe
abstract class Repository<T> {
Future<T?> find(String id);
Future<void> save(T entity);
}
// Bad: Dynamic typing
abstract class Repository {
Future<dynamic> find(String id);
Future<void> save(dynamic entity);
}
```
3. **Document Contracts**
```dart
/// Contract for caching implementations.
///
/// Implementations must:
/// - Handle serialization
/// - Be thread-safe
/// - Support TTL
abstract class Cache {
/// Gets a value from cache.
///
/// Returns null if not found.
/// Throws [CacheException] on error.
Future<T?> get<T>(String key);
}
```
## Next Steps
1. Implement core contracts
2. Add integration tests
3. Document Laravel compatibility
4. Add migration guides
5. Create examples
6. Write tests
Would you like me to enhance any other package specifications?
## Development Guidelines
### 1. Getting Started
Before implementing contracts:
1. Review [Getting Started Guide](getting_started.md)
2. Check [Laravel Compatibility Roadmap](laravel_compatibility_roadmap.md)
3. Follow [Testing Guide](testing_guide.md)
4. Use [Foundation Integration Guide](foundation_integration_guide.md)
### 2. Implementation Process
For each contract:
1. Write tests following [Testing Guide](testing_guide.md)
2. Implement following Laravel patterns
3. Document following [Getting Started Guide](getting_started.md#documentation)
4. Integrate following [Foundation Integration Guide](foundation_integration_guide.md)
### 3. Quality Requirements
All implementations must:
1. Pass all tests (see [Testing Guide](testing_guide.md))
2. Meet Laravel compatibility requirements
3. Follow integration patterns (see [Foundation Integration Guide](foundation_integration_guide.md))
### 4. Integration Considerations
When implementing contracts:
1. Follow patterns in [Foundation Integration Guide](foundation_integration_guide.md)
2. Ensure Laravel compatibility per [Laravel Compatibility Roadmap](laravel_compatibility_roadmap.md)
3. Use testing approaches from [Testing Guide](testing_guide.md)
4. Follow development setup in [Getting Started Guide](getting_started.md)