Easy way to return paginated querysets

[njncalub]

Is your feature request related to a problem? Please describe.

I'm looking for an easy and customizable way to return the paginated results to our endpoints.

curl 'http://localhost:5000/api/todo/?done=false&limit=5&offset=10'

{
  "count": 12,
  "limit": 5,
  "offset": 10,
  "results": [
    {
      "id": "5af24d6363f52000045bae0e",
      "text": "Suomio kvanto sh mil, krom manier sub id.",
      "done": false
    },
    {
      "id": "5af24d6363f52000045bae0f",
      "text": "Oid kv resti faras akuzativo.",
      "done": false
    }
  ]
}

There's an existing SomeModel.objects.paginate(page=1, per_page=20) that returns a Pagination object. Maybe we can utilize that?

Describe the solution you'd like

The most elegant way might be to use decorators:

@paginate(serializer=TodoType)
def list_items(done: http.QueryParam):
    if done:
        done = json.loads(done)
        return TodoModel.objects.filter(done=done)
    return TodoModel.objects.all()

But this approach mutates the function and the type annotations. This is also a little hacky since the decorator should find a way to get the limit and offset during wrapping.

Describe alternatives you've considered
We can create a PaginationComponent for the pagination settings and this also handles the limit and offset from QueryParams automatically:

def list_items(done: http.QueryParam, pgn: Pagination) -> Paginated[TodoType]:
    if done:
        queryset = TodoModel.objects(done=json.loads(done))
    else:
        queryset = TodoModel.objects.all()
    return pgn.paginate(queryset, serializer=TodoType)  # pgn should get the `limit` and `offset` automatically

Or just add it as a QuerySet method:

def list_items(done: http.QueryParam, limit: http.QueryParam, offset: http.QueryParam) -> Paginated[TodoType]:
    if done:
        queryset = TodoModel.objects(done=json.loads(done))
    else:
        queryset = TodoModel.objects.all()
    limit = json.loads(limit) or 10
    offset = json.loads(offset) or 0
    return queryset.paginated(serializer=TodoType, limit=limit, offset=offset)

Additional context

Still open for suggestions