Simplified usage of ServiceStack REST services.

Dtos.cs

// Response types omitted.
// Note that request types now marked with IRequest<TResponse> interface.
// This allows Send method to determine response type at compile time.

[RestService("/orders/{id}", "GET")]
[RestService("/orders/by-code/{code}", "GET")]
[RestService("/orders/search", "GET")]
public class GetOrders : IRequest<GetOrdersResponse> {
    public int? Id { get; set; }
    public string Code { get; set; }
    public string Name { get; set; }
    public string Customer { get; set; }
}
    
[RestService("/orders", "POST")] // to create new order.
[RestService("/orders/{id}", "PUT")] // to create or update existing order with specified Id.
public class SaveOrder : IRequest<SaveOrderResonse> {
    public int? Id { get; set; }
    // Order details.
}

RestServiceExtension.cs

// Marker interface allowing to determine response type at compile time.
public interface IRequest<TResponse> {
}

public static class RestServiceExtensions
{
    public static TResponse Send<TResponse>(this IRestClient client, IRequest<TResponse> request) {
        // Determine matching REST endpoint for specified request (via RestService attributes).
        // Populate url with encoded variables and optional query parameters.
        // Invoke corresponding REST method with proper Http method 
        // and return strongly typed response
       // is automatically determined by compiler.
    }
}

RestServiceUsage.cs

IRestClient client = new JsonServiceClient();

// We don't specify response type - it is determined automatically based on request type.
// We don't specify URLs or HTTP verbs - they are determined based on request state.
// We don't write boilerplate code to encode url parts. It is done automatically.

// GET /orders/5
var orderById = client.Send(new GetOrders { Id = 5 }).Orders.Single(); 

// GET /orders/by-code/Code
var orderByCode = client.Send(new GetOrders { Code = orderById.Code }).Orders.Single();

// GET /orders/search?Name=Name&Customer=Customer
var getOrders = new GetOrders { Name = orderById.Name, Customer = orderByCode.Customer };
var foundOrders = client.Send(getOrders).Orders;

// POST /orders
var createOrderResponse = client.Send(new SaveOrder { /* Order details */});

// PUT /orders/id
int orderId = createOrderResponse.Id;
var updateOrderResponse = client.Send(new SaveOrder { Id = orderById.Id, /* Order details */ });