How to update an existing entity that has a nested list of entities? - asp.net-core

Question

I'm trying to update an entity using entity framework but, everytime I try to do it, it raises an error saying that a nested entity the main class contains cannot be tracked.
These are my classes:
public abstract class BaseEntity
{
public int Id { get; set; }
}
public class Dashboard : BaseEntity
{
public int Order { get; set; }
public string Title { get; set; }
public bool Enabled { get; set; }
public virtual ICollection<Submenu> Submenu { get; set; }
}
public class Submenu : BaseEntity
{
public int Order { get; set; }
public bool Enabled { get; set; }
public string Title { get; set; }
public string Image { get; set; }
public string Descriptions { get; set; }
public virtual ICollection<Action> Actions { get; set; }
public int DashboardId { get; set; }
public virtual Dashboard Dashboard { get; set; }
}
public class Action : BaseEntity
{
public string Type { get; set; }
public string Label { get; set; }
public string Url { get; set; }
public string Extension { get; set; }
public virtual Submenu Submenu { get; set; }
public int SubmenuId { get; set; }
}
The one I am using to update is Dashboard, which contains the rest of the classes.
I'm trying to do it using a generic service layer and a generic repository that are defined this way:
public class GenericService<T> : IGenericService<T> where T : BaseEntity
{
private readonly IBaseRepository<T> baseRepository;
public GenericService(IBaseRepository<T> baseRepository)
{
this.baseRepository = baseRepository;
}
public async Task Update(T entity, T attachedEntity)
{
await baseRepository.Update(entity, attachedEntity);
}
}
public class BaseRepository<T> : IBaseRepository<T> where T : BaseEntity
{
private readonly PortalContext dataContext;
private DbSet<T> DbSet { get; set; }
public BaseRepository(PortalContext context)
{
dataContext = context;
DbSet = dataContext.Set<T>();
}
public async Task Update(T entity, T attachedEntity)
{
dataContext.Entry(attachedEntity).State = EntityState.Detached;
DbSet.Attach(entity);
dataContext.Entry(entity).State = EntityState.Modified;
await dataContext.SaveChangesAsync();
}
}
And, at last but no least, this is the way I am configuring everything at Startup.cs
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<PortalContext>(
options => options.UseSqlServer(Configuration.GetConnectionString("PortalContext"))
);
services.AddTransient(typeof(IGenericService<>), typeof(GenericService<>));
services.AddTransient(typeof(IBaseRepository<>), typeof(BaseRepository<>));
services.AddTransient<Func<string, ClaimsPrincipal, IRoleCheck>>((serviceProvider) =>
{
return (controllerName, claimsPrincipal) =>
new RoleCheck(serviceProvider.GetRequiredService<IGenericService<Dossier>>(),
serviceProvider.GetRequiredService<IGenericService<DossierTemplate>>(),
serviceProvider.GetRequiredService<IGenericService<Dashboard>>(),
controllerName, claimsPrincipal);
});
}
What the application first does is calling the RoleCheck class to retrieve and filter the required entities and, after that, the user can update them.
When I call the update function at the controller
public async Task<ActionResult<Dashboard>> Put(int id, [FromBody] Dashboard dashboard)
{
var currentDashboard = await service.Get(id);
if (currentDashboard == null)
{
return NotFound();
}
await service.Update(dashboard, currentDashboard);
return Ok();
}
I always receive the next error at the repository:
error
Is there something I am doing wrong? I have been stuck with this for a week now...
Thanks in advance and sorry for the long text, but I wanted it to be clear.

Answer 1

I could finally solve it by adding .AsNoTracking() at the Get() method of my repository:
public async Task<T> Get(int id, Func<IQueryable<T>, IIncludableQueryable<T, object>> includes)
{
IQueryable <T> query = DbSet.AsNoTracking();
if (includes != null)
{
query = includes(query);
}
return await query.FirstOrDefaultAsync(m => m.Id == id);
}