in my ASP.NET MVC application I have a service that had a method for paging, sorting and filtering of Vehicle Makes:

public class VehicleService : IVehicleService {     private readonly DbContext _context;      public VehicleService(DbContext context)     {         _context = context;     }      public async Task<IPagedList<VehicleMake>> GetVehicleMakesWithPaginationAsync(string search, int? page, string sort)     {         var makes = _context.VehicleMakes.AsQueryable();          switch (sort)         {             case "Name desc":                 makes = makes.OrderByDescending(x => x.Name);                 break;             default:                 makes = makes.OrderBy(x => x.Name);                 break;         }          return await makes.Where(x => x.Name.StartsWith(search) || search == null).ToPagedListAsync(page ?? 1, 5);     } } 

After the review of my code, I was told that sorting, filtering and paging should be in separate classes that have interfaces. I implemented that in following way:

Sorting:

internal class Sorting : ISorting {     private readonly DbContext _context;      public Sorting(DbContext context)     {         _context = context;     }      public IEnumerable<VehicleMake> SortMakes(string sort)     {         var makes = _context.VehicleMakes.AsQueryable();          makes = sort == "Name desc" ? makes.OrderByDescending(x => x.Name) : makes.OrderBy(x => x.Name);         return makes;     } } 

Paging:

class Paging : IPaging {     private readonly ISorting _sorting;      public Paging(DbContext context)     {         _sorting = new Sorting(context);     }      public async Task<IPagedList<VehicleMake>> GetPagedListOfSortedMakes(string search, int? page, string sort)     {         var sortedMakes = _sorting.SortMakes(sort).AsQueryable();         return await sortedMakes.Where(x => x.Name.StartsWith(search) || search == null).ToPagedListAsync(page ?? 1, 5);     } } 

And then in my service:

public class VehicleMakeService : IVehicleMakeService {     private readonly DbContext _context;     private readonly IPaging _paging;      public VehicleMakeService(DbContext context)     {         _context = context;         _paging = new Paging(context);     }      public async Task<IPagedList<VehicleMake>> GetVehicleMakesWithPaginationAsync(string search, int? page, string sort)     {         return await _paging.GetPagedListOfSortedMakes(search, page, sort);     } } 

This works well, but I’m not sure if I implemented this correctly. Is there a better (cleaner) way to do this?