Implement Pagination in ASP.NET Core 2.1 Web API

Question

I searched, but did't really found articles on how to implement pagination logic in an ASP.NET WebAPI Core 2.1 application...

I have the following

[Route("api/[controller]")]
[ApiController]
[EnableCors("AllowMyOrigin")]
public class EntriesController : ControllerBase
{
    private readonly EntriesContext _context;

    public EntriesController(EntriesContext context) {
        _context = context;

        if (_context.Entries.Count() == 0) {
            _context.Entries.Add(new Entry { From = "default", To = "default" });
            _context.SaveChanges();
        }
    }

    [HttpGet]
    public ActionResult<List<Entry>> GetAll() {
        return _context.Entries.ToList();
    }

    [HttpGet("{id}", Name = "GetEntry")]
    public ActionResult<Entry> GetById(long id) {
        var item = _context.Entries.Find(id);
        if (item == null) { return NotFound(); }
        return item;
    }

Now, I want my entries to be paginated using new params page and pageSize. Say

/api/entries?pageSize=3&page=2 

Should I use the GetAll() method by adding some http params to it, or rather create a new method? There are no much sense to use page without pageSize, how do I manage this?

Answer 1

First of all, you can default you pageSize value to something:

[HttpGet]
public ActionResult<List<Entry>> GetAll(int? page = null, int? pageSize = 10) 
{
    if (!page.HasValue) {
        return _context.Entries.ToList();
    }

    // do you pagination here
}

But you also may look at OData, it seems to be your case. It will allow you to query your data using http params, e.g.: /api/Entires?$skip=5&$top=5