CODEWITHSUNDEEP
c#.netlinqautomapperienumerable
Ignacio Sanhueza
Ignacio Sanhueza

Reputation: 82

Give default value using automapper casting two IEnumerables

I have to cast two IEnumerables objects, let's call it Obj1 and Obj2.

To do this, i use automapper to cast directly the two lists, like this:

config = new MapperConfiguration(cfg => {
            cfg.CreateMap<IEnumerable<Obj1>, IEnumerable<Obj2>>();
        });

        mapper = config.CreateMapper();

But i have a problem, because i want to give a default value to all the elements in the Obj2 list. Is there a way to do this keeping the IEnumerable cast?.

The only solution i have in mind is to create the mapper for the element itself and then iterate between all the elements in Obj1 list and cast to type Obj2, like this:

config = new MapperConfiguration(cfg => {
        cfg.CreateMap<Obj1, Obj2>();
    });

    mapper = config.CreateMapper();

And then, in a foreach element in the list of Obj1, cast and add to a list of type Obj2.

I want to do this directly in the mapper configuration, is there a way to do it, keeping the IEnumerable mapping?.

Thanks.

Upvotes: 0

Views: 119

Answers (1)

Georg Patscheider
Georg Patscheider

Reputation: 9463

If you have a map for the base objects, you do not need a map for collections of these objects. Instead, set the destination type when you call Map<TDestination>(). See AutoMapper Docs: Lists and Arrays.

config = new MapperConfiguration(cfg => {
    cfg.CreateMap<Obj1, Obj2>()
        .ForMember(dest => dest.ShouldBeDefaulted, 
                   o => o.MapFrom(src => src.ShouldBeDefaulted == null 
                        ? TheDefaultValue : src.ShouldBeDefaulted ));
});

var source = new List<Obj1>() { new Obj1("A"), new Obj1("B")};

// tell AutoMapper that the destination should be a collection during call to Map()
Obj2[] dest = mapper.Map<Obj2[]>(source);
Assert.AreEqual(2, dest.Length);

Upvotes: 1

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