Automapper before/after map callbacks during mapping - c#

I'm using ASP.NET Core and Automapper 6.1.0 ,
I have two types that look like this
public class ExampleDTO
{
public Guid Id { get; set; }
public ProviderDTO Provider { get; set; }
}
public class Example
{
public Guid Id { get; set; }
public Guid Provider { get; set; }
}
ProviderDTO class (which is irelevant in this case)
public class ProviderDTO
{
public Guid Id { get; set; }
public string Name { get; set; }
}
AutoMapper configuration looks like this:
CreateMap<Example, ExampleDTO>().ForMember(x => x.Provider, opt => opt.Ignore());
CreateMap<ExampleDTO, Example>().ForMember(dest => dest.Provider,
opt => opt.MapFrom(src => src.Provider.Id));
When I map from Example to ExampleDTO, I want to pass the value for ProviderDTO type.
I tried something like this.
_mapper.Map<ExampleDTO>(example, opt => opt.AfterMap((src, dest) => dest.Provider = myProvider));
I get this
'object' does not contain a defenition for 'Provider' and no extension method
Is this achievable? If yes, what am I doing wrong?

With the AutoMapper, you may need to provide both the source and destination type, such as:
_mapper.Map<Example, ExampleDTO>(example, opt => {
opt.AfterMap((src, dest) => dest.Provider = myProvider))
});

Related

Unable to map from one ViewModel to another

I'm making a list of checkboxes to update a user's roles, and I'm trying to map from this:
public class ApplicationRoleViewModel
{
public Guid Id { get; set; }
public string Name { get; set; }
public string NormalizedName { get; set; }
public string ConcurrencyStamp { get; set; }
public int SortOrder { get; set; }
public string DisplayName { get; set; }
public string Description { get; set; }
public string Icon { get; set; } // Font Awesome-ikoner, f.eks. "fa-user"
}
to this:
public class SelectableRoleViewModel
{
public Guid Id { get; set; }
public string DisplayName { get; set; }
public bool Selected { get; set; }
}
This is my mapping:
CreateMap<ApplicationRoleViewModel, SelectableRoleViewModel>()
.ForMember(dest => dest.Id, s => s.MapFrom(i => i.Id))
.ForMember(dest => dest.DisplayName, s => s.MapFrom(d => d.DisplayName))
.ForMember(dest => dest.Selected, i => i.Ignore());
Mapping it like this in the controller:
ApplicationRole role = await db.Roles.FirstOrDefaultAsync();
SelectableRoleViewModel sr = auto.Map<SelectableRoleViewModel>(role);
gives me the following error message:
AutoMapperMappingException: Missing type map configuration or unsupported mapping.
I am registering AutoMapper in Startup.cs like this:
services.AddAutoMapper(typeof(Startup));
Then, in AutoMapperProfile.cs:
public class AutomapperProfile : Profile
{
public AutomapperProfile()
{
// This is not working:
CreateMap<ApplicationRoleViewModel, SelectableRoleViewModel>()
.ForMember(dest => dest.Selected, i => i.Ignore());
// This is working:
CreateMap<ApplicationUser, ApplicationUserViewModel>();
// Many more mappings, all working
}
}
How can I get it to work?
The code you specified seems to be correct.
I will just suggest to remove the ForMember method for properties with the same names as auto mapper handles it automatically:
CreateMap<ApplicationRoleViewModel, SelectableRoleViewModel>()
.ForMember(dest => dest.Selected, i => i.Ignore());
The problem seems to be because you are not using the mapper right. Where have you registered the mapper? Is the registration happens before the map? Did you do it in the Startup? If you specify more code, it will be easier to help.
UPDATE:
After getting more code & info, the problem was that the map worked on a different object, ApplicationRoleViewModel and not ApplicationRole.
Just to see a difference ;)
public static SelectableRoleViewModel ToSelectable(this ApplicationRoleViewModel model)
{
return new SelectableRoleViewModel
{
Id = model.Id,
DisplayName = model.DisplayName
};
}
// Usage
var selectable = applicationRole.ToSelectable();
Type it once
Perfectly testable
Fully maintainable - supports all kinds of conversion/mapping
Reduce amount of injected dependencies and abstractions (mapper)
No extra dependencies on third party libraries

AutoMapper - How map complex objects to simpler model

I want map Origin.CityId and Origin.StateId properties of
Itinerary class to OriginCityId and OriginStateId properties
of ItineraryModel class.
Ex: Itinerary itinerary = Mapper.Map<Itinerary>(ItineraryModel);
My ViewModel
public class ItineraryModel : BaseModel
{
public int OriginCityId { get; set; }
public int OriginStateId { get; set; }
public bool Published { get; set; }
}
My Entity
public class Itinerary : BaseEntity
{
public City Origin { get; set; }
public bool Published { get; set; }
}
My mapping that tried do
public class MappingProfile : Profile
{
public MappingProfile()
{
CreateMap<ItineraryModel, Itinerary>()
.ForPath(x => x.Origin.CityId, opt => opt.MapFrom(src => src.OriginCityId))
.ForPath(x => x.Origin.StateId, opt => opt.MapFrom(src => src.OriginStateId))
.ReverseMap();
}
}
I would like to too .ReverseMap() but can't find right syntax.
You need to add two mappings for mapping to Itenerary
CreateMap<ItineraryModel, City>()
.ForMember(city => city.CityId, expression => expression.MapFrom(itineraryModel => itineraryModel.OriginCityId))
.ForMember(city => city.StateId, expression => expression.MapFrom(itineraryModel => itineraryModel.OriginStateId));
CreateMap<ItineraryModel, Itinerary>()
.ForMember(itinerary => itinerary.Origin, expression => expression.MapFrom(itineraryModel => itineraryModel));
Similarly you can define reverse mappings manually if needed.
BTW ReverseMap() is not recommended by author
https://jimmybogard.com/automapper-usage-guidelines/

Automapper: How to flatten complex object to plain object

public class Complex
{
public A A { get; set; }
public A B { get; set; }
}
public class A
{
public int a1 { get; set; }
public int a2 { get; set; }
}
public class B
{
public int b1 { get; set; }
public int b2 { get; set; }
}
//----------------Source Object End Here---------------------
public class Simple <----[This Simple class has only properties of A class]
{
public int aa1 { get; set; }
public int aa2 { get; set; }
}
//----------------Destination Object End Here---------------------
CreateMap<A, Simple>()
.ForMember(dest => dest.aa1, opt => opt.MapFrom(src => src.a1))
.ForMember(dest => dest.aa2, opt => opt.MapFrom(src => src.a2))
// Mapper IS NOT AVAILABLE HERE AS I AM USING PROFILE BASED CONFIGURATION
CreateMap<Complex, Simple>()
.ConvertUsing(src => Mapper.Map<A, Simple>(src.A)); <------Error at this line
//----------------Automammer config End Here---------------------
How to flatten from Complex to Simple? I don't wish to map Complex.A to Simple one by one again in the Complex to Simple config as it is already configured above.
Finally, I figured out with another overloaded method of ConvertUsing
CreateMap<Complex, Simple>()
.ConvertUsing((src,ctx) => {
return ctx.Mapper.Map<Complex, Simple>(src.A)
});
I feel this overloaded method has quite a multiple possibilities and flexibility. I don't have further issue of accessing Mapper directly as mentioned in the question. This overloaded method has its own context parameter (ResolutionContext). We can use Mapper from this context parameter like ctx.Mapper.Map<Complex, Simple>(src.A)

AutoMapper: What is the difference between ForMember() and ForPath()?

I am reading AutoMapper's ReverseMap() and I can not understand the difference between ForMember() and ForPath(). Implementations was described here. In my experience I achieved with ForMember().
See the following code where I have configured reverse mapping:
public class Customer
{
public string Surname { get; set; }
public string Name { get; set; }
public int Age { get; set; }
}
public class CustomerDto
{
public string CustomerName { get; set; }
public int Age { get; set; }
}
static void Main(string[] args)
{
Mapper.Initialize(cfg =>
{
cfg.CreateMap<Customer, CustomerDto>()
.ForMember(dist => dist.CustomerName, opt => opt.MapFrom(src => $"{src.Surname} {src.Name}"))
.ReverseMap()
.ForMember(dist => dist.Surname, opt => opt.MapFrom(src => src.CustomerName.Split(' ')[0]))
.ForMember(dist => dist.Name, opt => opt.MapFrom(src => src.CustomerName.Split(' ')[1]));
});
// mapping Customer -> CustomerDto
//...
//
// mapping CustomerDto -> Customer
var customerDto = new CustomerDto
{
CustomerName = "Shakhabov Adam",
Age = 31
};
var newCustomer = Mapper.Map<CustomerDto, Customer>(customerDto);
}
It is working.
Question
Do ForMember and ForPath the same things or when should I use ForPath() over ForMember()?
In this case, to avoid inconsistencies, ForPath is translated internally to ForMember. Although what #IvanStoev says makes sense, another way to look at it is that ForPath is a subset of ForMember. Because you can do more things in ForMember. So when you have a member, use ForMember and when you have a path, use ForPath :)

Need help with AutoMapper

I have two classes that looks as follows:
public class Rule
{
public int Id { get; set; }
public RuleGroup RuleGroup { get; set; }
}
public class RuleGroup
{
public int Id { get; set; }
public List<Rule> RuleList { get; set; }
}
A RuleGroup has a list of rules. My AutoMapper settings are as follows:
Mapper.CreateMap<RuleRecord, FirstSolar.Mes.Core.Entities.Recipe.Rule>()
.ForMember(destination => destination.RuleGroup, source => source.Ignore())
.ForMember(destination => destination.Id, source => source.MapFrom(item => item.RuleId));
Mapper.CreateMap<IList<RuleRecord>, IList<FirstSolar.Mes.Core.Entities.Recipe.Rule>>();
Mapper.CreateMap<RuleGroupRecord, FirstSolar.Mes.Core.Entities.Recipe.RuleGroup>()
.ForMember(destination => destination.Id, source => source.MapFrom(item => item.RuleGroupId));
Mapper.CreateMap<IList<RuleGroupRecord>, IList<FirstSolar.Mes.Core.Entities.Recipe.RuleGroup>>();
When I attempt to map a RuleGroupRecord (LinqToSQL object) to RuleGroup (DTO), AutoMapper says I need to add a mapping for RuleGroup.RuleList. I'm wondering why because I defined how to map a single RuleRecord and a List.
If I have to, how would I do it?
Simply add (I hope I got the syntax right, but you should see what I'm hinting at):
.ForMember(destination => destination.RuleList, source => source.MapFrom(item => item.Rules));
to the second mapping. While you handled the general mapping for RuleRecord to Rule in the first mapping, you didn't tell automapper to map the specific property RuleGroup.RuleList.

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