Automapper and NHibernate: lazy loading

Question

I have the following scenario.

public class DictionaryEntity
{
    public virtual string DictionaryName { get; set; }

    public virtual IList<DictionaryRecordEntity> DictionaryRecord { get; set; }
}

public class DictionaryDto
{
     public string DictionaryName { get; set; }

     public IList<DictionaryRecordEntity> DictionaryRecord { get; set; }
}

I'm using Automapper and NHibernate. In NHibernate the DictionaryRecord property is marked as lazy loaded.

When I make the mapping from DictionaryEntity -> DictionaryDto, Automapper loads all my DictionaryRecords.

But I don't want this behavior, is there a way to configure the Automapper in order to don't resolve this property until I really access this property.

My workaround for this situation consists of splitting the DictionaryEntity in 2 classes and create a second Automapper mapping.

public class DictionaryDto
{
     public string DictionaryName { get; set; }
}

public class DictionaryDtoFull : DictionaryDto
{
     public IList<DictionaryRecordEntity> DictionaryRecord { get; set; }
}

and then in the code, depending on the need, call AutoMapper.Map appropriately.

return Mapper.Map<DictionaryDto>(dict);            
return Mapper.Map<DictionaryDtoFull>(dict);

Does somebody have a better solution for my problem?

Najera · Accepted Answer · 2017-12-08 18:43:22Z

3

You must add a condition to validate if the collection is initialized to be mapped. You can read here more details: Automapper: Ignore on condition of.

AutoMapper.Mapper.CreateMap<DictionaryEntity, DictionaryDto>()
    .ForMember(dest => dest.DictionaryRecord, opt => opt.PreCondition(source =>
        NHibernateUtil.IsInitialized(source.DictionaryRecord)));

edited Dec 8, 2017 at 18:43

answered May 11, 2015 at 20:40

Najera

2,8793 gold badges30 silver badges52 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Mischa Over a year ago

Altough it's not exactly what I'm looking for, I think this is the best solution for what's possible. Thanks

Adam Over a year ago

@Najera are you sure this is correct? As I understand it Condition happens after the mapping and PreCondition should be used. See stackoverflow.com/questions/40658582/… (or maybe it was correct but things have changed with automapper?)

Najera Over a year ago

@Adam You are right, all I remember I made a tested and it worked for a couple of projects, but PreCondition is the correct way to do it in last versions. Thanks

nik0lai · Accepted Answer · 2015-05-11 13:38:30Z

0

You could ignore the property, if this is of use?

AutoMapper.Mapper.CreateMap<DictionaryEntity, DictionaryDto>()
    .ForMember(dest => dest.DictionaryRecord,
               opts => opts.Ignore());

http://cpratt.co/using-automapper-mapping-instances/

answered May 11, 2015 at 13:38

nik0lai

2,66524 silver badges37 bronze badges

2 Comments

Mischa Over a year ago

Thanks for your quick response. I think that's not useful for me. In this case the DictionaryRecord list would just be empty, right?

nik0lai Over a year ago

You're probably right, although you could have two methods one that has the above code and ignores one and one that loads all of the properties lazy style. I'm not sure AutoMapper can do what you're asking.

Collectives™ on Stack Overflow

Automapper and NHibernate: lazy loading

2 Answers 2

3 Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related