Mapping EF collection using AutoMapper and EF Reverse POCO Generator - asp.net-mvc

Question

I was handed a project which is using EF Database first, EF Reverse POCO generator, and Auto Mapper. I'm really struggling getting a many-to-many relationship to be modeled properly using all three pieces and would appreciate any help.
I have the following tables in my DB:
+=================+ +==================+ +================+
| Event | | Event_Format | | Format |
+=================+ +==================+ +================+
| Id | | Id | | Id |
| Title | | EventId | | Name |
| Created | | FormatId | | Created |
| CreatedBy | | Created | | CreatedBy |
| | | CreatedBy | | |
+=================+ +==================+ +================+
This generates three POCO classes in my data layer:
public class Event {
public int Id { get; set; } // Id (Primary key)
public string Title { get; set; } // Title
public DateTime Created { get; set; } // Created
public string CreatedBy { get; set; } // CreatedBy
public virtual ICollection<EventFormat> EventFormats { get; set; } // Event_Format.FK_Event_Format_Event
}
public class EventFormat
{
public int Id { get; set; } // Id (Primary key)
public int EventId { get; set; } // EventId
public int FormatId { get; set; } // FormatId
public DateTime Created { get; set; } // Created
public string CreatedBy { get; set; } // CreatedBy
public virtual Event Event { get; set; } // FK_Event_Format_Event
public virtual Format Format { get; set; } // FK_Event_Format_Format
}
public class Format
{
public int Id { get; set; } // Id (Primary key)
public string Name { get; set; } // Name
public DateTime Created { get; set; } // Created
public string CreatedBy { get; set; } // CreatedBy
public virtual ICollection<EventFormat> EventFormats { get; set; } // Event_Format.FK_Event_Format_Format
}
In my MVC project I have a view model for Events and Formats (but not EventFormats as it seems unneeded).
public class Event.ViewModel
{
public int Id { get; set; }
public string Title { get; set; }
public DateTime Created { get; set; }
public string CreatedBy { get; set; }
public List<Format.ViewModel> Formats { get; set; }
}
public class Format.ViewModel
{
public int Id { get; set; }
public string Name { get; set; }
public DateTime Created { get; set; }
public String CreatedBy { get; set; }
}
Here are the Mapper profiles:
protected internal class BookingProfile : Profile
{
public new string ProfileName = "Admin_Booking";
protected override void Configure()
{
CreateMap<Data.Models.Event, Models.Booking.WisconsinFilmFest.ViewModel>()
.ForMember(dst => dst.Created, x => x.MapFrom(src => src.Created.ToLocalTime()))
.ForMember(dst => dst.EventFormats, x => x.MapFrom(src => src.EventFormats.ToList()));
}
}
protected internal class FormatProfile : Profile
{
public new string ProfileName = "Admin_Format";
protected override void Configure()
{
CreateMap<Data.Models.Format, Models.Format.ViewModel>()
.ForMember(dst => dst.Created, x => x.MapFrom(src => src.Created.ToLocalTime()))
.ForMember(dst => dst.Modified, x => x.MapFrom(src => src.Modified.ToLocalTime()));
}
}
When I attempt to use AutoMapper to map an Event to an Event.ViewModel it doesn't work because EF returns the EventFormat type instead (because of the extra columns). Is there a way to tell Automapper to get the Format of each EventFormat item and then map those into the Formats property on the ViewModel?
Currently what I'm doing is using the AfterMap() feature of Automapper, and looping through each item in EventFormats to get the Format and add it to the ViewModel's property like so:
protected internal class BookingProfile : Profile
{
public new string ProfileName = "Admin_Booking";
protected override void Configure()
{
CreateMap<Data.Models.Event, Models.Booking.WisconsinFilmFest.ViewModel>()
.ForMember(dst => dst.Created, x => x.MapFrom(src => src.Created.ToLocalTime()))
.ForMember(dst => dst.EventFormats, x => x.Ignore())
.AfterMap((src, dst) =>
{
if(src.EventFormats.Any(x => x.Format.Deleted == null))
{
foreach(Data.Models.EventFormat ef in src.EventFormats)
{
dst.EventFormats.Add(Mapper.Map(ef.Format, new Models.Format.ViewModel()));
}
}
});
}
This feels somewhat hacky to me and I was hoping there was a better way to do this.

Answer 1

Sure you can. Specify that AutoMapper should map Event.ViewModel.Formats to EventFormats.Select(ef => ef.Format):
Mapper.CreateMap<Format,Format.ViewModel>();
Mapper.CreateMap<Event,Event.ViewModel>()
.ForMember(dest => dest.Formats,
m => m.MapFrom(src => src.EventFormats.Select(ef => ef.Format)));
Now you can do
var result = db.Events.ProjectTo<Event.ViewModel>();

Answer 2

You should be able to just update the first mapping in the profile to read like this:
CreateMap<Data.Models.Event, Models.Booking.WisconsinFilmFest.ViewModel>()
.ForMember(dst => dst.Created, x => x.MapFrom(src => src.Created.ToLocalTime()))
.ForMember(dst => dst.Formats, x => x.MapFrom(src => src.EventFormats.Select(y => y.Format).ToList()));
As it stands, the profile is telling the mapper to project the source type's EventFormats property into the destination's EventFormats property, when it sounds like what you really want is to project the EventFormats.Format property into a Formats collection.