Entity Framework Kernel Configurations

Question

In EF 6, we could directly pass an EntityTypeConfiguration to build a map model and keep our configuration class separate from the context, without being too verbose in the code.

Have these cards been removed in the EF core. Is there a way to add a configuration without doing it in the model builder for each class?

Answer 1

The best way is to keep the configuration code away from the method OnModelCreating. So you can do something like:

Create a class in which you save the actual configuration:

public class ApplicationUserConfiguration
{
    public ApplicationUserConfiguration(EntityTypeBuilder<ApplicationUser> entity)
    {
        // Here you have all the good stuff
        entity.ToTable("user", "identity");

        entity.Property(p => p.Id)
            .HasColumnName("id);

        // And so on ....
    }
}

OnModelCreating :

protected override void OnModelCreating(ModelBuilder builder)
{
    base.OnModelCreating(builder);

    // Your custom configs here
    new ApplicationUserConfiguration(builder.Entity<ApplicationUser>());
}

.

Answer 2

EntityFrameworkCore2.0 IEntityTypeConfiguration<TEntity>, :

class ApplicationUserMap : IEntityTypeConfiguration<ApplicationUser>
{
  public void Configure(EntityTypeBuilder<Customer> builder)
  {
    builder.ToTable("user", "identity");

    builder.Property(p => p.Id)
        .HasColumnName("id");
     ...
   }
}

...
// OnModelCreating
modelBuilder.ApplyConfiguration(new ApplicationUserMap());

Answer 3

, ?

, , .

, EF 6.

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    Type[] types = typeof(EntityTypeConfiguration<>).GetTypeInfo().Assembly.GetTypes();
    IEnumerable<Type> typesToRegister = types
        .Where(type => !string.IsNullOrEmpty(type.Namespace) &&
                        type.GetTypeInfo().BaseType != null &&
                        type.GetTypeInfo().BaseType.GetTypeInfo().IsGenericType &&
                        type.GetTypeInfo().BaseType.GetGenericTypeDefinition() == typeof(EntityTypeConfiguration<>));

    foreach (var type in typesToRegister)
    {
        dynamic configurationInstance = Activator.CreateInstance(type);
        ModelBuilderExtensions.AddConfiguration(modelBuilder, configurationInstance);
    }

    base.OnModelCreating(modelBuilder);
}

public abstract class EntityTypeConfiguration<TEntity> where TEntity : class
{
    public abstract void Map(EntityTypeBuilder<TEntity> builder);
}

public static class ModelBuilderExtensions
{
    public static void AddConfiguration<TEntity>(ModelBuilder modelBuilder, EntityTypeConfiguration<TEntity> configuration)
        where TEntity : class
    {
        configuration.Map(modelBuilder.Entity<TEntity>());
    }
}

public class UserMap : EntityTypeConfiguration<User>
{
    public override void Map(EntityTypeBuilder<User> builder)
    {
        // Primary Key
        builder.HasKey(t => t.Id);
        ...
    } 
}