How to map inner generic type?

[oraad]

Hi, I'm trying to figure out how to map an inner property of generic type.

Consider the dto class
class PageableDto<T> { number: number content: T[] }
to be mapped to
class Pageable<T> { page: number content: T[] }

And I have the possible inner types
class BookDto { title: string; author: string; }
class Book { title: string; author: string; }

class MovieDto { title: string; director: string; releasedOn: Date; }
class Movie { title: string; director: string; date: Date; }

How can I map PageableDto<BookDto> -> Pageable<Book> and PageableDto<MovieDto> -> Pageable<Movie> ?
I'm getting undefined for Pageable.content when I map.

[jampack]

bump

[oraad]

One solution/workaround I did, is to use mapDefer since I have two types to be passed in this case.

createMap(mapper, PageableDto, Pageable,
    forMember(dest => dest.content,
        mapDefer(src => {
            if (src.content?.[0] instanceof BookDto)
                return mapWith(Book, BookDto, src => src.content)

            if (src.content?.[0] instanceof MovieDto)
                return mapWith(Movie, MovieDto, src => src.content)

            // handle all other types not yet specified as is
            return mapFrom(src => src.content)
        })
    )
)

The problem with this solution, is that it becomes very verbose if we have more inner types to map from.

[nartc]

Hey @oraad, this is a limitation right now with AutoMapper. We will have to think about supporting this with a reasonable API. mapDefer would have been my suggestion as well and I am aware of its verbosity.