automapper unexpected fields c#

Question

I am trying to map a simple model to an entity but get a list of unmapped items that I was not expecting, it fails at the validation line of AutomapperCfg:

SaveImportRunDetailsModel -> ImportRunDetailEntity (Destination member list) FCSD.Models.SaveImportRunDetailsModel -> LLBLGEN.EntityClasses.ImportRunDetailEntity (Destination member list)

Unmapped properties:

Id
ConcurrencyPredicateFactoryToUse
AuthorizerToUse
AuditorToUse
Validator
ActiveContext
IsNew
Fields
IsDirty

These look like system generated items, is there a way to dismiss them?

AutomapperCfg.cs is

using AutoMapper;
using FCSD.Models;
using LLBLGEN.EntityClasses;

namespace FCSD.Automapper
{
    public class AutomapperCfg : IAutomapperCfg
    {
        public void Configure()
        {
            Mapper.Initialize(cfg =>
            {
                cfg.CreateMap<CategoryEntity, Category>(MemberList.Destination);
                cfg.CreateMap<EnglishPartInfoEntity, EnglishPartModel>(MemberList.Destination);
                cfg.CreateMap<ImageEntity, Image>(MemberList.Destination);
                cfg.CreateMap<ImportRunDetailEntity, ImportRunDetailModel>(MemberList.Destination);
                cfg.CreateMap<ModelExportBaseEntity, Model>(MemberList.Destination).ReverseMap();
                cfg.CreateMap<PartEntity, Part>(MemberList.Destination);

                cfg.CreateMap<SaveImportRunDetailsModel, ImportRunDetailEntity>(MemberList.Destination);
            });

            Mapper.AssertConfigurationIsValid();
        }
    }
}

The SaveImportRunDetailsModel is

using System;

namespace FCSD.Models
{
    public class SaveImportRunDetailsModel
    {
        public string PHCreationDate { get; set; }
        public DateTime RunTimestamp { get; set; }
    }
}

lastly, the ImportRunDetailEntity is a bit long (over 400 lines) and is autogenerated c# from LLBLGen Pro.

I removed AutoMapper from the Solution because it was trying to process inside the LLBLGen base classes. The ignore rules to get past this were going to be as much effort of writing my own maps. — Tim, Aug 11 '15 at 10:53
Tom, yes I tried ignore, plus making separate reverse direction maps where needed. — Tim, Aug 13 '15 at 17:32

score 1 · Accepted Answer · edited May 23 '17 at 11:51

What's Happening

AutoMapper will throw an exception if your destination type contains any properties it cannot match to a property on the source, if it has not been told explicitly how to fill that property.

How to fix it

If you do not wish AutoMapper to fill a property, you're expected to use this extension method on the CreateMap<TSource, TDest>()'s return, for each field to ignore:

 .ForMember(dest => dest.Id, opt => opt.Ignore())
 .ForMember(dest => dest.ConcurrencyPredicateFactoryToUse, opt => opt.Ignore())
 .ForMember(dest => dest.AuthorizerToUse, opt => opt.Ignore());

and so on.

But that sucks...

Obviously this is a bit of a drag and takes the "auto" right out of AutoMapper, so you may want to consider something like this AutoMapper: "Ignore the rest"? - which will automatically ignore all destination members which are non-existing on the source object.

One more thing

You might want to write a unit test which configures a Mapper instance with all your Mappings, then call Mapper.AssertConfigurationIsValid() to discover any issues at Test Time rather than at Run Time, as by default, AutoMapper will not bother validating a mapping until the first time you attempt to use it.

automapper unexpected fields c#

1 Answers1