Skip to main content

Flattening and unflattening

It is pretty common to flatten objects during mapping, eg. Car.Make.Id => CarDto.MakeId. Mapperly tries to figure out flattenings automatically by making use of the pascal case C# notation. If Mapperly can't resolve the target or source property correctly, it is possible to manually configure it by applying the MapPropertyAttribute by either using the source and target property path names as arrays or using a dot separated property access path string

[MapProperty([nameof(Car.Make), nameof(Car.Make.Id)], [nameof(CarDto.MakeId)])]
// Or alternatively
[MapProperty("Make.Id", "MakeId")]
// Or
[MapProperty($"{nameof(Make)}.{nameof(Make.Id)}", "MakeId")]
partial CarDto Map(Car car);

Unflattening is not automatically configured by Mapperly and needs to be configured manually via MapPropertyAttribute.

Experimental full nameof‚Äč

Mapperly supports an experimental "fullnameof". It can be used to configure property paths using nameof. Opt-in is done by prefixing the path with @.

[MapProperty(nameof(@Car.Make.Id), nameof(CarDto.MakeId))]
partial CarDto Map(Car car);

@nameof(Car.Make.Id) will result in the property path Make.Id. The first part of the property path is stripped. Make sure these property paths start with the type of the property and not with a namespace or a property.


This is an experimental API. Its API surface is not subject to semantic releases and may break in any release.