Interface IMediator

Namespace

Arbiter.Mediation

Assembly

Arbiter.Mediation.dll

An interface defining a mediator to encapsulate request/response and publishing patterns.

public interface IMediator

Examples

Example usage of IMediator:

// Define a request and response
public record HelloRequest(string Name) : IRequest<string>;

public class HelloRequestHandler : IRequestHandler<HelloRequest, string>
{
    public ValueTask<string> Handle(HelloRequest request, CancellationToken cancellationToken)
    {
        return ValueTask.FromResult($"Hello, {request.Name}!");
    }
}

// Define a notification
public record HelloNotification(string Message) : INotification;

public class HelloNotificationHandler : INotificationHandler<HelloNotification>
{
    public ValueTask Handle(HelloNotification notification, CancellationToken cancellationToken)
    {
        Console.WriteLine($"Notification received: {notification.Message}");
        return ValueTask.CompletedTask;
    }
}

// Usage
var services = new ServiceCollection();
// Register Mediator services
services.AddMediator();

// Register Handlers
services.AddScoped<IRequestHandler<HelloRequest, string>, HelloRequestHandler>();
services.AddScoped<INotificationHandler<HelloNotification>, HelloNotificationHandler>();

var provider = services.BuildServiceProvider();

var mediator = provider.GetRequiredService<IMediator>();

// Sending a request
var response = await mediator.Send(new HelloRequest("World"));
Console.WriteLine(response); // Output: Hello, World!

// Publishing a notification
await mediator.Publish(new HelloNotification("This is a test notification"));

Methods

Publish<TNotification>(TNotification, CancellationToken)

Sends a notification to multiple handlers.

ValueTask Publish<TNotification>(TNotification notification, CancellationToken cancellationToken = default) where TNotification : INotification

Parameters

notification TNotification

The notification to send.

cancellationToken CancellationToken

Cancellation token.

Returns

ValueTask

Awaitable task for the notification operation.

Type Parameters

TNotification

The type of notification being sent.

Exceptions

ArgumentNullException

Thrown when notification is null.

Send(object, CancellationToken)

Sends a request to the appropriate handler and returns the response.

ValueTask<object?> Send(object request, CancellationToken cancellationToken = default)

Parameters

request object

The request to send to the handler. The request object must implement IRequest<TResponse> interface.

cancellationToken CancellationToken

Cancellation token.

Returns

ValueTask<object>

Awaitable task returning the handler response.

Exceptions

ArgumentNullException

Thrown when request is null.

InvalidOperationException

Thrown when request does not implement IRequest<TResponse> interface.

Send<TResponse>(IRequest<TResponse>, CancellationToken)

Sends a request to the appropriate handler and returns the response.

ValueTask<TResponse?> Send<TResponse>(IRequest<TResponse> request, CancellationToken cancellationToken = default)

Parameters

request IRequest<TResponse>

The request to send to the handler.

cancellationToken CancellationToken

Cancellation token.

Returns

ValueTask<TResponse>

Awaitable task returning the TResponse.

Type Parameters

TResponse

The type of response from the handler.

Exceptions

ArgumentNullException

Thrown when request is null.

Send<TRequest, TResponse>(TRequest, CancellationToken)

Sends a request to the appropriate handler and returns the response.

ValueTask<TResponse?> Send<TRequest, TResponse>(TRequest request, CancellationToken cancellationToken = default) where TRequest : IRequest<TResponse>

Parameters

request TRequest

The request to send to the handler.

cancellationToken CancellationToken

Cancellation token.

Returns

ValueTask<TResponse>

Awaitable task returning the TResponse.

Type Parameters

TRequest

The type of request being sent.

TResponse

The type of response from the handler.

Exceptions

ArgumentNullException

Thrown when request is null.