Why does my django pagination keeps returning the same items infinitely?

Question

I am using django and ajax to create a infinite scroll on my website. I would like it to load more items from the database (that are in the next page) when the user scrolls to the bottom of the page. Everything is working perfectly except that it keeps returning the first page's items infinitely. For example if a user scrolls down to the end of a page instead of adding page 2's elements it just add the same elements from the first page to the bottom again. I am very sure this issue is from my views.py. I can't seem to figure out what's wrong.

def feed(request):
    queryset2 = Store_detail.objects.filter(store_lat__gte=lat1, store_lat__lte=lat2)\
    .filter(store_lng__gte=lng1, store_lng__lte=lng2)
queryset3 = Paginator(queryset2, 4)
    page = request.GET.get('page',1)
    try:
         queryset = queryset3.page(1)
    except PageNotAnInteger:
        queryset = queryset3.page(page)
    except EmptyPage:
        queryset = ""
    context = {
        "location":location,
        "queryset":queryset,
    }
    # return HttpResponse(template.render(context,request))
    return render(request, 'main/feed.html', {'queryset': queryset, 
'location':location,})

So basically I would like to load the next page when a user scrolls to the end of the screen and if there are no more items in the next page or the next page does not exist then stop adding items.

Because you each time first page with page is `1`. – Willem Van Onsem Aug 11 '19 at 12:19 — Willem Van Onsem, Aug 11 '19 at 12:19
So I should just leave it as page? – Opp Aug 11 '19 at 12:23 — Opp, Aug 11 '19 at 12:23

score 1 · Accepted Answer · answered Aug 11 '19 at 12:22

1

The pagination logic is a bit off. You paginate with:

try:
    # you first try to retrieve page 1
    queryset = queryset3.page(1)
except PageNotAnInteger:
    queryset = queryset3.page(page)
except EmptyPage:
    queryset = ""

This thus means that you first aim to fetch the first page, and only if 1 is not an integer, you will fetch a page with the page querystring parameter. You should swap these, like:

try:
    queryset = queryset3.page(page)
except PageNotAnInteger:
    queryset = queryset3.page(1)
except EmptyPage:
    queryset = Store_detail.objects.none()

answered Aug 11 '19 at 12:22

Willem Van Onsem

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Although I'm sure that's a better way to put it, it's still loading the same items infinitely. – Opp Aug 11 '19 at 12:25
@Osaro: are you sure you query with a querystring: so `some_url.com/some/path?page=2`? What URL do you see in the server console? – Willem Van Onsem Aug 11 '19 at 12:26
@Osaro: then your AJAX call probably is not entirely correct, it needs to add a `?page=...` part with `...` the page you aim to fetch. – Willem Van Onsem Aug 11 '19 at 12:31
It's adding the ?page=... but it's not adding it to the page. It's adding it to the item links. – Opp Aug 11 '19 at 12:34
@Osara: what do you mean with adding it to the "item links"? I assume you have some JavaScript that fetches the next pages, correct? That should fetch the rest of the pages (as HTML, JSON, or some other format), and "inject" it in the DOM. – Willem Van Onsem Aug 11 '19 at 12:35
Yes you're correct. {% if queryset.has_next %} {% endif %} Basically it uses that link to check the next page. But there is no page in the url of the page. – Opp Aug 11 '19 at 12:37
@Osaro: where does the `numbers` variable originates from? Shouldnt this be `queryset.next_page_number`? – Willem Van Onsem Aug 11 '19 at 13:12
You're right that was the issue. Just replaced it now and it's working. Thanks! – Opp Aug 11 '19 at 13:37

Why does my django pagination keeps returning the same items infinitely?

1 Answers1