I have a Student object:
public class Student
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
And a Classroom object:
public class Classroom
{
public List<Student> Students { get; set; }
}
I want to use AutoMapper to convert the list of students to a list of student IDs:
public class ClassroomDTO
{
public List<int> StudentIds { get; set; }
}
How do I configure AutoMapper to do this conversion?
Answer:
To expand on my question and Jimmy's answer, this is what I ended up doing:
Mapper.CreateMap<Student, int>().ConvertUsing(x => x.Id);
Mapper.CreateMap<Classroom, ClassroomDTO>()
.ForMember(x => x.StudentIds, y => y.MapFrom(z => z.Students));
AutoMapper was smart enough to do the rest.
You'll need a custom type converter:
Mapper.CreateMap<Student, int>().ConvertUsing(src => src.Id);
Related
I've got the majority of my automapper maps working but I'm facing a problem trying to translate an enum from the value to the string when part of list of child objects. I have the enum to string converter working when at the top level but it seems when I am converting from RecipeStep to RecipeStepResource it isn't using the map defined for Ingredient to IngredientResource and therefore the conversion from enum to string isn't being called.
I've looked around but can't seem to find a similar example to work from and am having trouble deciphering the automapper help on this which says it should automatically pick up the map defined, which it doesn't seem to be, unsure if this is because the Ingredient items are part of a list. Major code snippets below, any help appreciated.
Model:
public class RecipeStep
{
[Required]
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int ID { get; set; }
public string Description { get; set; }
public IList<Ingredient> Ingredients { get; set; }
public Timer Timer { get; set; }
public int RecipeID { get; set; }
[JsonIgnore]
[IgnoreDataMember]
[ForeignKey("RecipeID")]
public Recipe Recipe { get; set; }
}
public class Ingredient
{
[Required]
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int ID { get; set; }
[Required]
[StringLength(50)]
public string Name { get; set; }
[Required]
public ETypeOfIngredient Type { get; set; }
[Required]
public double Amount { get; set; }
[Required]
public EUnitOfMeasure Unit { get; set; }
public int RecipeStepID { get; set; }
[JsonIgnore]
[IgnoreDataMember]
[ForeignKey("RecipeStepID")]
public RecipeStep RecipeStep { get; set; }
}
Resources:
public class RecipeStepResource
{
public int ID { get; set; }
public string Description { get; set; }
public List<IngredientResource> Ingredients { get; set; }
public TimerResource Timer { get; set; }
}
public class IngredientResource
{
public int ID { get; set; }
public string Type { get; set; }
public string Name { get; set; }
public double Amount { get; set; }
public string Unit { get; set; }
public int RecipeStepID { get; set; }
}
Mapping code:
CreateMap<Ingredient, IngredientResource>()
.ForMember(src => src.Type,
opt => opt.MapFrom(src => src.Type.ToDescriptionString()))
.ForMember(src => src.Unit,
opt => opt.MapFrom(src => src.Unit.ToDescriptionString()));
CreateMap<Timer, TimerResource>();
CreateMap<RecipeStep, RecipeStepResource>()
.ForMember(dest => dest.Ingredients,
opt => opt.MapFrom(src => src.Ingredients))
.ForMember(src => src.Timer,
opt => opt.MapFrom(src => src.Timer));
Enum to string conversion code:
public static string ToDescriptionString<TEnum>(this TEnum #enum)
{
FieldInfo info = #enum.GetType().GetField(#enum.ToString());
var attributes = (DescriptionAttribute[])info.GetCustomAttributes(typeof(DescriptionAttribute), false);
return attributes?[0].Description ?? #enum.ToString();
}
What I have tried:
Creating an Ingredient -> IngredientResource map
Creating a List<Ingredient> -> List<IngredientResource> map
Adding an AfterMap call to the List<Ingredient> -> List<IngredientResource> map to convert the enum value
None of these have worked. Really struggling to understand why AutoMapper is not picking up the Ingredient to IngredientResource map for a List property on the RecipeStep object, I thought it would have done this automatically.
The issue came down to the parent object, I had it incorrectly mapped with both the model and resource files referring to RecipeStep, instead of RecipeStep -> RecipeStepResource. Really want to thank #Lucian for helping me and making me go back to basics to work through the understanding from a simpler standpoint and building up to a representative model.
I'm trying to create map for automapper to let me map those entity
Entities
public class Entity
{
...
public List<NavigationEntity> Navs { get; set; }
}
public class NavigationEntity
{
public int Id { get; set; }
}
DTO that need to be create with entities
public class EntityDto
{
...
public List<int> NavIds { get; set; }
}
This doesnt seem's to do the job! What could do the job ?
CreateMap<Entity, EntityDto>().ReverseMap();
CreateMap<NavigationEntity, int>().ConstructUsing(x => x.Id);
EDIT
Tried to add
CreateMap< List < SystemsTags >, List< int >>();
but still it doesnt map
First of all, you should rename public List<NavigationEntity> Navs { get; set; } and public List<int> NavIds { get; set; } to the same name. If it is still not working try to also change ConstructUsing to ConvertUsing. And if you need the reverseMap of Entity to EntityDTO you should also add
CreateMap<int, NavigationEntity>().ConvertUsing(x => new NavigationEntity { Id = x });
final code
public class Entity
{
...
public List<NavigationEntity> Navs { get; set; }
}
public class NavigationEntity
{
public int Id { get; set; }
}
public class EntityDto
{
...
public List<int> Navs { get; set; }
}
...
CreateMap<Entity, EntityDto>().ReverseMap();
CreateMap<NavigationEntity, int>().ConvertUsing(x => x.Id);
CreateMap<int, NavigationEntity>().ConvertUsing(x => new NavigationEntity { Id = x });
I have this Party class which contains an object data type coming from a service. It can contain two different member types for the Item property.
public class Party
{
public string DMVID {get; set;}
public object Item { get; set; }
}
and this DTO
public class PartyDTO
{
public string DMVID {get; set;}
public BusinessDTO BusinessItem { get; set; }
public IndividualDTO IndividualItem { get; set; }
}
How can I map the output of the Item to BusinessItem or IndividualItem.
I know this one would not work. Mapper.CreateMap<Party, PartyDTO>();
I don't know if conditional mapping can solve this or a resolver like this one.
Hey maybe this will help you out! I tested it, but i am using AutoMapper just for two days!
Allright here are your noted classes!!!
public class Party
{
public string DMVID { get; set; }
public object Item { get; set; }
}
public class PartyDTO
{
public string DMVID { get; set; }
public BuisnessDTO BusinessItem { get; set; }
public IndividualDTO IndividualItem { get; set; }
}
public class BuisnessDTO
{
public int Number
{
get;
set;
}
}
public class IndividualDTO
{
public string Message
{
get;
set;
}
}
and here your is the MapperConfiguration for this current scenario!
// Edit There was no need here for some conditions
AutoMapper.Mapper.CreateMap<Party, PartyDTO>()
.ForMember(dto => dto.BusinessItem, map =>
map.MapFrom(party => party.Item as BuisnessDTO);
)
.ForMember(dto => dto.IndividualItem, map =>
map.MapFrom(party => party.Item as IndividualDTO);
);
// And this is another way to achive the mapping in this scenario
AutoMapper.Mapper.CreateMap<PartyDTO, Party>()
.ForMember(party => party.Item, map => map.MapFrom( dto => (dto.BusinessItem != null) ? (dto.BusinessItem as object) : (dto.IndividualItem as object)));
And i created this sample for it!
Party firstParty = new Party()
{
DMVID = "something",
Item = new BuisnessDTO()
{
Number = 1
}
};
Party secondParty = new Party()
{
DMVID = "something",
Item = new IndividualDTO()
{
Message = "message"
}
};
PartyDTO dtoWithBuisness = AutoMapper.Mapper.Map<PartyDTO>(firstParty);
PartyDTO dtoWithIndividual = AutoMapper.Mapper.Map < PartyDTO>(secondParty);
Party afterParty = AutoMapper.Mapper.Map<Party>(dtoWithBuisness);
afterParty = AutoMapper.Mapper.Map < Party>(dtoWithIndividual);
Of course there are other possibility, but I think thats exactly what you wanted.
I am trying to map out some nested lists into a list of flattened structures using automapper.
Currently I am able to map the correct number of credits with names but I can not get the role and role description to map across.
I am trying to get a flattened list like this.
John Smith, Actor, Dr Evil
John Smith, Writer, null
Frank Brown, Director, null
Joe Green, Actor, Henchman
Here is a cutdown version of my domain model, view model and mapping.
What am I doing wrong with the Domain.Credit to ViewModel.Credit mapping?
//Domain Model
public class Talent
{
public virtual string FirstName { get; set; }
public virtual string LastName { get; set; }
public virtual IList<Credit> Credits { get; set; }
}
public class Credit
{
public virtual Role Role { get; set; }
public virtual string Subtitle { get; set; }
}
public class Role
{
public virtual string Title { get; set; }
}
//View Model
public class EpisodeViewModel
{
public IList<Credit> Credits { get; set; }
public class Credit
{
public string Name { get; set; }
public string Role { get; set; }
public string RoleDescription { get; set; }
}
}
//Mappings
Mapper.CreateMap<Episode, EpisodeViewModel>()
.ForMember(destination => destination.Credits, options => options.MapFrom(source => source.Talent));
Mapper.CreateMap<Talent, Credit>()
.ForMember(destination => destination.Name, options => options.MapFrom(source => string.Format("{0} {1}", source.FirstName, source.LastName)));
Mapper.CreateMap<Domain.Credit, Credit>()
.ForMember(destination => destination.Role, options => options.MapFrom(source => source.Role.Title))
.ForMember(destination => destination.RoleDescription, options => options.MapFrom(source => source.Subtitle));
As a new fan of AutoMapper, how would I use it to do the following:
Given the following classes, I want to create FlattenedGroup from Group where the list of item string maps to the title property of Item.
public class Group
{
public string Category { get; set; }
public IEnumerable<Item> Items { get; set; }
}
public class Item
{
public int ID { get; set; }
public string Title { get; set; }
}
public class FlattenedGroup
{
public string Category { get; set; }
public IEnumerable<string> Items { get; set; }
}
Thanks
Joseph
The other thing you can do is create a converter from Item -> string:
Mapper.CreateMap<Item, string>().ConvertUsing(item => item.Title);
Now you don't need to do anything special in your Group -> FlattenedGroup map:
Mapper.CreateMap<Group, FlattenedGroup>();
That's all you'd need there.
Give this a try, you can probably use Linq and a lambda expression to map the list of strings in FlattenedGroup with the titles in Group.
Mapper.CreateMap<Group, FlattenedGroup>()
.ForMember(f => f.Category, opt => opt.MapFrom(g => g.Category))
.ForMember(f => f.Items, opt => opt.MapFrom(g => g.Items.Select(d => d.Title).ToList()));
Make sure you add System.Linq to your using statements