EF Core AutoHistory Custom AutoHistory

Microsoft.EntityFrameworkCore.AutoHistory allows you to use a custom auto history entity by extending the Microsoft.EntityFrameworkCore.AutoHistory class.

class MyCustomAutoHistory : AutoHistory
{
    public String MyCustomField { get; set; }
}

Once you add your custom auto history class, you need to register it within your context class. Let's update the OnModelCreating to register your auto history class, as shown below.

public class BookStore : DbContext
{
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer(@"Data Source=(localdb)\ProjectsV13;Initial Catalog=BookStoreDb;");
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.EnableAutoHistory<MyCustomAutoHistory>(o => { });
    }

    public DbSet<Author> Authors { get; set; }
    public DbSet<Book> Books { get; set; }
}

Now when you call an EnsureAutoHistory, then you provide a custom history entity.

public static void Example1()
{
    using (var context = new BookStore())
    {
        var author = context.Authors.FirstOrDefault();
        author.Name = "Jones";

        context.EnsureAutoHistory(() => new MyCustomAutoHistory()
        {
            MyCustomField = "You custom value"
        });
        context.SaveChanges();
    }
}