RenderEntityDetailsAction.cs

public class RenderEntityDetailsAction<TEntity, TRequestModel, TDetailsModel> 
    where TEntity : class
    where TRequestModel : class
    where TDetailsModel : class
{
	private readonly IEntityService _entityService;
	private readonly IMappingRegistry _mappingRegistry;

	public RenderEntityDetailsAction(IEntityService entityService, IMappingRegistry mappingRegistry)
	{
		_mappingRegistry = mappingRegistry;
		_entityService = entityService;
	}

        public TDetailsModel Get(TRequestModel requestModel)
	{
            var entity = _entityService.Get<TEntity>(requestModel);
            if (entity == null)
            {
                throw new EntityNotFoundException<TEntity>(string.Format("{0} could not be found.", typeof(TEntity).Name));
            }

            return _mappingRegistry.Map<TEntity, TDetailsModel>(entity);
	}
}