Generic mappings

Mapperly supports generic user defined mapping methods. Mapperly implements this mapping method using all mappings the user defined in the mapper that satisfy the source and target type constraints.

[Mapper]
public static partial class ModelMapper
{
    public static partial TTarget MapFruit<TTarget>(Fruit source);

    private static partial BananaDto MapBanana(Banana source);
    private static partial AppleDto MapApple(Apple source);
}

class Fruit {}
class Banana : Fruit {}
class Apple : Fruit {}

class BananaDto {}
class AppleDto {}

Runtime target type parameter

If the target type of a mapping is not known at compile time, a mapping method with a Type parameter can be used. Mapperly implements this mapping method using all mappings the user defined in the mapper.

[Mapper]
public static partial class ModelMapper
{
    public static partial object Map(object source, Type targetType);

    private static partial BananaDto MapBanana(Banana source);
    private static partial AppleDto MapApple(Apple source);
}

class Banana {}
class Apple {}

class BananaDto {}
class AppleDto {}

Type constraints

If the source or target type of a runtime target type mapping is not object or the generic type has constraints, only user mappings of which the source/target type is assignable to the source/target type of the mapping method are considered.

Generic mappings and runtime target type parameter mappings support derived type mappings. The MapDerivedTypeAttribute can be directly applied to a mapping method.

info

Mapperly generic mappings and runtime target type parameter mappings only support source/target type combinations which are defined as mappings in the same mapper. If an unknown source/target type combination is provided at runtime, an ArgumentException is thrown.