Showpitch Advanced Part 1: Using Neat Architecture for Domain Services

After 3 weeks of high level review of Showpitch we’re going to dive in to more advanced topics. This week we’re going to cover the specifics of using Neat Architecture for Showpitch.

Neat Architecture

Showpitch uses the Neat Architecture to allow for very rapid development and a great amount of flexibility and power. You can find the Neat Architecture in practice on GitHub, so check it out when you have a chance! Now let’s get in to what Neat Architecture is.

Neat Components

Neat starts with several important components, all from NuGet:

  • ASP.Net Web Api
    • Microsoft.AspNet.Cors.5.2.3
    • Microsoft.AspNet.WebApi.5.2.3
    • Microsoft.AspNet.WebApi.Client.5.2.3
    • Microsoft.AspNet.WebApi.Core.5.2.3
    • Microsoft.AspNet.WebApi.Cors.5.2.3
    • Microsoft.AspNet.WebApi.Tracing.5.2.3
    • Microsoft.AspNet.WebApi.WebHost.5.2.3
  • Microsoft Practices Unity 3
    • CommonServiceLocator.1.3
    • Unity.3.5.1404.0
    • Unity.Interception.3.5.1404.0
    • Unity.WebAPI.5.1
  • OData
    • Microsoft.AspNet.WebApi.OData.5.5.1
    • Microsoft.Data.Edm.5.6.0
    • Microsoft.Data.OData.5.6.0
    • System.Spatial.5.6.0
  • NLog
    • NLog.4.0.1
    • NLog.MongoDB.0.7.0
    • mongocsharpdriver.1.8.3
  • JSON.Net
    • Newtonsoft.Json.6.0.4
    • Newtonsoft.Json.7.0.1
  • Octopack
    • OctoPack.3.0.42
  • MongoRepository
    • MongoRepository.1.6.8
    • mongocsharpdriver.1.10.0

Neat Solution Structure

The Solution Structure is comprised of a pretty traditional N-Tier stack. This stack is broken out in to a few more layers to facilitate further decoupling and reduce friction among components.

  • Neat.Model – All Domain Models
  • Neat.Data – Common Data Access Definition
  • Neat.Data.Mongo – Mongo Data Access Implementation
  • Neat.Infrastructure – Components for Application Functionality
  • Neat.Application – Core Business Logic
  • Neat.Service – Orchestration of Business Logic Components
  • Neat.Infrastructure.WebApi – Web Api Specific Functional Components
  • Neat.Web.Api – Web Api Host

A Closer Look at Unity and IoC in Neat

In Neat we use a class called Bootstrapper in each project to configure all Type Registrations for that project. We then expose an Attach method in each Bootstrapper, allowing components that rely on that project to run that project’s configuration against that component’s Unity container. Here’s an example:

public static class Bootstrapper
{
    public static void Register()
    {
        var container = new UnityContainer();

        Register(container);
    }

    public static void Attach(IUnityContainer container)
    {
        Register(container);
    }

    private static void Register(IUnityContainer container)
    {
        Neat.Data.Mongo.Bootstrapper.Attach(container);
        Neat.Infrastructure.Bootstrapper.Attach(container);

        container.RegisterType(typeof (IDomainApplication<>),
            typeof (DomainApplication<>),
            new ContainerControlledLifetimeManager());

        container.RegisterAllService<IApplication>();
    }
}

There’s a lot happening in this code:

  • The Attach Method – Components that depend on this one pass their container in here so that this component can register its classes on the same container
  • The Two Attach Calls – This component in turn calls Attach on the components it depends on
  • The typeof Registrations – This is how to register the generic implementation so that any type passed to the generic results in a resolvable type. Using this registration pattern throughout the stack these components can handle any domain object from the Web Api through to the Database
  • RegisterAllService – This is an Unity Extension in Neat that registers every class as the default registration for its other interfaces when it has the marker interface specified
  • ContainerControlledLifetimeManager – This lifetime manager ensures that the type registered is resolved as a Singleton

A Closer Look at the Web Api Controller in Neat

The Controllers in Neat use the generic Domain stack to expose the Domain Models. Here’s an example:

public class NeatController : BaseReadWriteDeleteController<NeatExample>
{
    public NeatController(IDomainService<NeatExample> domainService)
        : base(domainService)
    {}
}

As you can see, using the Unity registration from before and this Controller pattern, we’re able to rapidly expose Api Services for new Domain Models. But where are the methods? The answer lies in the BaseReadWriteDeleteController:

public class BaseReadWriteDeleteController<T> : BaseApiController where T : class, IEntity<string>, new()
{
    private readonly IDomainService<T> _domainService;

    public BaseReadWriteDeleteController(IDomainService<T> domainService)
    {
        _domainService = domainService;
    }

    // GET api/{T}
    [EnableQuery]
    public IQueryable<T> Get()
    {
        return _domainService.GetAll();
    }

    // GET api/{T}/{id}
    public T Get(string id)
    {
        return _domainService.GetById(id);
    }

    // POST api/{T}
    public void Post([FromBody]T entity)
    {
        _domainService.Add(entity);
    }

    // PUT api/{T}
    public void Put([FromBody]T entity)
    {
        _domainService.Update(entity);
    }

    // DELETE api/{T}/{id}
    public void Delete(string id)
    {
        _domainService.Delete(id);
    }

    // GET api/{T}/getempty
    [HttpGet]
    public T GetEmpty()
    {
        return new T();
    }
}

This pattern works very well with MongoRepository due to its generic implementation. Perhaps in a future post we’ll cover an Entity Framework Code First approach for this.

This architecture allows for very rapid application development. To add a new Domain Service to this stack the steps are simply:

  1. Add a new Domain Model
  2. Add a new Controller and inherit from the appropriate Base Controller with the right methods
  3. Profit!

In future posts we’ll cover how to add additional behavioral capabilities in to this architecture and extend it with other service features. Is there a specific part of this architecture that you have questions about? Is there another part of Neat you saw on GitHub that you want me to write about next? Please leave a comment below to let me know! And keep checking back for more info about Showpitch and Neat!

<< Back to Showpitch 103
On to Showpitch Advanced Part 2 >>

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Published by

John Brunnings

Thinker. Problem Solver. Technologist. Entrepreneur.

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