NorthwindTraders is a sample application built using ASP.NET Core and Entity Framework Core, showcasing Clean Architecture principles. It demonstrates how to implement a modern web application using domain-driven design and CQRS (Command Query Responsibility Segregation) patterns, providing a practical example for developers to learn from and use as a reference.

Pros

• Implements Clean Architecture, promoting separation of concerns and maintainability
• Uses modern ASP.NET Core and Entity Framework Core technologies
• Demonstrates CQRS pattern implementation
• Includes comprehensive unit and integration tests

Cons

• May be overly complex for simple applications or beginners
• Requires understanding of multiple design patterns and architectural concepts
• Limited documentation for some advanced features
• Sample data might not cover all real-world scenarios

Code Examples

1. Domain Entity Example:

public class Product : AuditableEntity
{
    public int ProductId { get; set; }
    public string ProductName { get; set; }
    public int? SupplierId { get; set; }
    public int? CategoryId { get; set; }
    public string QuantityPerUnit { get; set; }
    public decimal? UnitPrice { get; set; }
    public short? UnitsInStock { get; set; }
    public short? UnitsOnOrder { get; set; }
    public short? ReorderLevel { get; set; }
    public bool Discontinued { get; set; }

    public Category Category { get; set; }
    public Supplier Supplier { get; set; }
}

2. CQRS Query Example:

public class GetProductsListQuery : IRequest<ProductsListVm>
{
    public class GetProductsListQueryHandler : IRequestHandler<GetProductsListQuery, ProductsListVm>
    {
        private readonly IApplicationDbContext _context;
        private readonly IMapper _mapper;

        public GetProductsListQueryHandler(IApplicationDbContext context, IMapper mapper)
        {
            _context = context;
            _mapper = mapper;
        }

        public async Task<ProductsListVm> Handle(GetProductsListQuery request, CancellationToken cancellationToken)
        {
            var products = await _context.Products
                .ProjectTo<ProductDto>(_mapper.ConfigurationProvider)
                .OrderBy(p => p.ProductName)
                .ToListAsync(cancellationToken);

            var vm = new ProductsListVm
            {
                Products = products,
                CreateEnabled = true
            };

            return vm;
        }
    }
}

3. Controller Example:

[Authorize]
public class ProductsController : ApiController
{
    [HttpGet]
    public async Task<ActionResult<ProductsListVm>> GetAll()
    {
        return await Mediator.Send(new GetProductsListQuery());
    }

    [HttpGet("{id}")]
    public async Task<ActionResult<ProductDto>> Get(int id)
    {
        return await Mediator.Send(new GetProductQuery { Id = id });
    }

    [HttpPost]
    public async Task<ActionResult<int>> Create(CreateProductCommand command)
    {
        return await Mediator.Send(command);
    }
}

Getting Started

1. Clone the repository:

   git clone https://github.com/jasontaylordev/NorthwindTraders.git
   

2. Navigate to the project directory:

   cd NorthwindTraders
   

3. Restore dependencies and build the solution:

   dotnet restore
   dotnet build
   

4. Update the database:

   cd src/WebUI
   dotnet ef database update
   

5. Run the application:

   dotnet run
   

The application should now be running on https://localhost:5001.