Reduce duplication of code in switch with select?

Question

I have this switch with select

switch (sorting)
            {
                case "newest":
                {
                        var userId = User.Identity.GetUserId();
                        var model = db.Posts.Include(p => p.Vote)
                            .OrderByDescending(p => p.PostId).ToList()
                            .Select(p => new ListPostsViewModel
                            {
                                UserVotedUpOnPost = p.Vote.Any(u => u.ApplicationUserID == userId && u.PostVote == 1),
                                UserVotedDownOnPost = p.Vote.Any(u => u.ApplicationUserID == userId && u.PostVote == -1),
                                PostId = p.PostId.ToString(),
                                TimeAgo = ToRelativeDate(p.MessageDate),
                                Message = p.Message,
                                TotalVotes = p.Vote.Sum(v => v.PostVote)
                            }).ToList();
                    return View("Index", model);

                } break;

                case "oldest":
                    {
                        var userId = User.Identity.GetUserId();
                        var model = db.Posts.Include(p => p.Vote)
                            .OrderBy(p => p.PostId).ToList()
                            .Select(p => new ListPostsViewModel
                            {
                                UserVotedUpOnPost = p.Vote.Any(u => u.ApplicationUserID == userId && u.PostVote == 1),
                                UserVotedDownOnPost = p.Vote.Any(u => u.ApplicationUserID == userId && u.PostVote == -1),
                                PostId = p.PostId.ToString(),
                                TimeAgo = ToRelativeDate(p.MessageDate),
                                Message = p.Message,
                                TotalVotes = p.Vote.Sum(v => v.PostVote)
                            }).ToList();
                        return View("Index", model);
                    }
                    break;
}

As you can see, the only line that is different is .OrderByDescending(p => p.PostId).ToList() and I will have a few more similar but how can I write it without duplicate all the code in the select etc?

`var data= db.Posts.Include(p => p.Vote);` Then your switch statements to order it - `case "newest": data = data.OrderBy(...)` etc and finally `var model = data.Select(....` — , Oct 24 '16 at 13:05

score 1 · Answer 1 · answered Oct 24 '16 at 13:04

Something like:

var qry = db.Posts.Include(p => p.Vote);
select (sorting) {
  case "newest":
    qry = qry.OrderBy(x => x.Date);
    break;

  case "oldest":
    qry = qry.OrderByDescending(x => x.Date);
    break;
}
var res = qry.Select(p => new ListPostsViewModel {
                       …
                     });
 return View("Index, res);

Reduce duplication of code in switch with select?

1 Answers1