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

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

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

^{Results may (probably) vary}

• 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.Map<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.

Developed with ❤️ at Doğuş Teknoloji.