Handling REST collections of child entities...

SongCollectionController.cs

/*
  When a user posts multiple songs to the controller, I want it to redirect back to 
  the Get endpoint. However, I don't believe asp.net's Routing handles that.
*/
[Route("api/songbooks/{songbookId}/songcollections")]
public class SongCollectionController : Controller
{

  [HttpGet("{id}", Name = "GetSongCollection")]
  public IActionResult GetSongCollection(Guid songbookId, [ModelBinder(BinderType = typeof(ArrayModelBinder))]IEnumerable<Guid> ids)
  {
      //..SNIP..
  }

  [HttpPost]
  public IActionResult Post(Guid songbookId, [FromBody]IEnumerable<SongCreate> songCollection)
  {
      //..SNIP..
      _repository.Save(songbook);

      var idsAsString = string.Join(",", songs.Select(sb => sb.Id));

      return CreatedAtRoute("GetSongCollection", new { SongbookId = songbook.Id, Ids = idsAsString }, _mapper.Map<IEnumerable<SongResult>>(songs),);
  }
}