dogusteknoloji/batmap

🦇 Convention-based, fast object mapper.

BatMap - The Mapper we deserve, not the one we need.

Opininated (yet another) mapper, mainly to convert between EF Entities and DTOs.

Supports .Net Standard 1.0.

Let's first obey the number one rule for mappers, a benchmark (using BenchmarkDotNet):

Method	Mean
HandWritten	1.143 ms
BatMap 💥	2.000 ms
SafeMapper	2.933 ms
Mapster	2.942 ms
AutoMapper	3.497 ms
TinyMapper	4.172 ms
ExpressMapper	6.955 ms
FastMapper	9.203 ms

^{Results may (probably) vary. Latest run can bee seen on Appveyor Build.}

• Fast (enough)
• NOT over-engineered, code is really simple
• Instantiatable mapper
• Convention based, zero configuration static shortcut exists too (obviously named Mapper)
• Does not crash when faced with circular-dependencies during registration
• In fact, can resolve recurring instances to same target instance (yaay no StackOverflowException!)
• Can project IQueryable<TSource> to IQueryable<TTarget> with respect to includes (via auto-detection or with custom parameters)
• and much more...

API

Registration with static API:

Mapper.RegisterMap<Customer, CustomerDTO>();

or use an instance:

var mapper = new MapConfiguration(dynamicMapping: DynamicMapping.MapAndCache, preserveReferences: true);
mapper.RegisterMap<Customer, CustomerDTO>();

Note: You don't have to register type mappings when using a MapConfiguration with Dynamic Mapping enabled (like the static API uses).

You can customize expressions for members:

mapper.RegisterMap<Order, OrderDTO>(b => b.MapMember(o => o.Price, (o, mc) => o.Count * o.UnitPrice));

Map an object:

Mapper.Map<CustomerDTO>(customer);

Map an enumerable:

customers.MapTo<Customer, CustomerDTO>(preserveReferences: true);  // extension methods FTW!

Project a query:

customerQuery.ProjectTo<CustomerDTO>(checkIncludes: true);

or with expanding specific navigations:

customerQuery.ProjectTo<Customer, CustomerDTO>(c => c.Addresses, c => c.Orders);

Note: If you want to change mapping behavior, create a class that inherits from ExpressionProvider, override CreateMemberBinding and inject an instance of your class to MapConfiguration.

Where can I get it?

You can install BatMap from the package manager console:

PM> Install-Package BatMap

Documentation

You might want to visit wiki for more.

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Developed with ❤️ at Doğuş Teknoloji.

batmap's Issues

A bit strange benchmark results

It's a bit strange that HandWritten is not the first. BatMap is a really nice project, but benchmark result looks a bit strange. Looks like HandWrittensample has a bug, yes it's possible to do this kind of mapping but it's a bit inefficient. try to use ConverAll method, it'll remove all ToList methods (except one, IList does not have ConvertAll

like this

public void HandWritten()
{
	var customerDTOs = _customers.Select(c => new CustomerDTO
	{
		Id = c.Id,
		Addresses = c.Addresses.ConvertAll(a => new AddressDTO
		{
			City = new CityDTO
			{
				Id = a.City.Id,
				Name = a.City.Name,
				Population = a.City.Population
			},
			Detail = a.Detail,
			Id = a.Id
		}),
		CompanyName = c.CompanyName,
		Endorsement = c.Endorsement,
		Orders = c.Orders.ConvertAll(o => new OrderDTO
		{
			Id = o.Id,
			OrderDetails = o.OrderDetails.ConvertAll(od => new OrderDetailDTO
			{
				Id = od.Id,
				Count = od.Count,
				UnitPrice = od.UnitPrice
			}),
			OrderNo = o.OrderNo,
			Price = o.Price
		}),
		Phone = c.Phone
	}).ToList();
}

BTW, I think other mappers support collection mapping, so it's possible to map without ToList

For instance, there's no Select

        public void BatMap() {
            var customerDTOs = _customers.Map<Customer, CustomerDTO>().ToList();
        }

but here's Select and ToList

        [Benchmark]
        public void TinyMapper() {
            var customerDTOs = _customers.Select(c => Nelibur.ObjectMapper.TinyMapper.Map<Customer, CustomerDTO>(c)).ToList();
        }

        [Benchmark]
        public void ExpressMapper() {
            var customerDTOs = _customers.Select(c => global::ExpressMapper.Mapper.Map<Customer, CustomerDTO>(c)).ToList();
        }

for any performance comparisonce, it's really impotant compare the same things in an equeal environment.

Map<TIn, TOut>(src, dest)

apply mapping to an existing object.

possible use-case
user posts an update (using a DTO) to an existing object. the service loads the existing object from the DB, and then use the map(dto, entity) to apply the updates as required.

Example Usage

public void Update(PersonDto personDto) {
    var person = _session.Get<Person>(personDto.id);
    _mapper.Map(personDto, person);
}

note that the dto may only contain a subset of the entity properties

Mapper.Map<TSource, TDestination>() not work when TDestination not have parameterless public ctor

BatMap version

1.1.3 (from NuGet)

Steps to reproduce

Mapper.RegisterMap(typeof(MyEntity), typeof(MyDto)); // MyDto doesn't have parameterless public ctor
var dto = Mapper.Map<MyEntity, MyDto>(new MyEntity(1, "Bla"));

Expected behavior

dto.Id.Equals(1);
dto.Name.Equals("Bla");

Actual behavior

dto.Id.Equals(0);
dto.Name.Equals(string.Empty);

@umutozel @onselakin @unalkarakus ?

"Ambiguous match found" when getting property

Reported by: tungtrungvn

BatMap version

1.1.12

Steps to reproduce

It happens when we use "new" keyword to hide property from parent class

Expected behavior

Should use property from inherited class

Actual behavior

Throws "Ambiguous match found" exception

Doesn't detect ThenInclude navigations from queries

BatMap version

1.1.2

Steps to reproduce

Using ThenInclude with queries

Expected behavior

Should map all Include and ThenInclude navigations

Actual behavior

Only maps Include navigations, skips ThenInclude navigations

how to get the different fields/properies when before/after mapped ?

how to get the different fields/properies when before/after mapped ?

how to got the mapped result is that update some fields/properies ?

same question mark in agileobjects/AgileMapper#229