MappingRepository

Reduce your boilerplate code when mapping between your entity and domain layers. Simply have your repositories and entities inherit from the provided classes and interfaces, define your AutoMapper config and you're done. Supports IoC injection of database context and AutoMapper configuration.

Getting started

In your project that will hold domain layer repositories: Install-Package MappingRepository

In your projects that hold DTOs and EF Entities: Install-Package MappingRepository.Interfaces

Deriving from the provided classes

Derive your own repository from the MappingRepository base class:

public class CustomerRepository : MappingRepository<Customer, CustomerDto, Guid>
{
    public CustomerRepository(IMappingRepositoryContext dbContext, IMapper mapper)
        : base(dbContext, mapper)
    { }
}

Implementing the interfaces

Have your entities and DTOs implement the supplied interfaces. Your objects on both sides must implement a common key type, e.g. Guid or int.

public class Customer : IMappingRepositoryEntity<Guid>
{
    public Guid Id;
    public string FirstName;
    public string Surname;
    
    [Computed]
    public string Name => this.FirstName + " " + this.Surname;
}

public class CustomerDto : IMappingRepositoryDestination<Guid>
{
    public Guid Id;
    public string Name;
}

If you want to use IoC to inject your database context, have it implement IMappingRepositoryContext:

public class MyContext : System.Data.Entity.DbContext, IMappingRepositoryContext

Mapping objects

Define your maps with AutoMapper's non-static API:

var config = new MapperConfiguration(cfg =>
{
    cfg.CreateMap<Customer, CustomerDto>();
    
    cfg.CreateMap<CustomerDto, Customer>()
        .ForMember(d => d.Id, o => o.Ignore())
        .ForMember(d => d.FirstName, o => o.MapFrom(s => s.Name.Split(' ')[0]))
        .ForMember(d => d.Surname, o => o.MapFrom(s => s.Name.Split(' ')[1]));
});

var mapper = config.CreateMapper();

Put it to use

Grab your data through a number of built-in methods, or build upon the provided queryables to extend the base functionality:

var repo = new CustomerRepository(new MyContext(), mapper);

var id = Guid.Parse("205b9dc9-1fd1-4be6-881f-f18c9a32d95a");
var customer1 = repo.GetById(id);

var customer2 = repo.FirstOrDefault(x => x.Name.Equals("Sarah Barnes"));

var customersWithOrders = repo.FindBy(x => x.Orders.Any());

var customerDropDownList = repo.ProjectTo<CustomerDropDown>();

Efficiency

MappingRepository utilises projections, meaning EF will only select the data it needs to populate your DTOs. It also includes support for DelegateDecompiler, allowing the querying of computed properties in your maps.

public class Order : IMappingRepositoryEntity<Guid>
{
    public Guid Id;
    public Guid CustomerId;
    
    public ICollection<Line> Lines;
    
    [Computed]
    public string Total => this.Lines.Sum(x => x.Amount);
}

var highValueCustomers = repo.FindBy(x => x.Orders.Where(y => y.Total > 1000), i => i.Orders.Select(x => x.Lines));