Flexible pagination in Django

Question

I'd like to implement pagination such that I can allow the user to choose the number of records per page such as 10, 25, 50 etc. How should I go about this? Is there an app I can add onto my project to do this?

Thanks

Answer 1

google on "django pagination" and make sure to use "covering index" in your SQL for efficient query.

Answer 2

Django has a Paginator object built into core. It's a rather straightforward API to use. Instantiate a Paginator class with two arguments: the list and the number of entries per "page". I'll paste some sample code at the bottom.

In your case you want to allow the user to choose the per-page count. You could either make the per-page count part of the URL (ie. your/page/10/) or you could make it a query string (ie. your/page/?p=10).

Something like...

# Assuming you're reading the Query String value ?p=
try:
    per_page = int(request.REQUEST['p'])
except:
    per_page = 25     # default value

paginator = Paginator(objects, per_page)

Here's some sample code from the Django doc page for the Paginator to better see how it works.

>>> from django.core.paginator import Paginator
>>> objects = ['john', 'paul', 'george', 'ringo']
>>> p = Paginator(objects, 2)

>>> p.count
4
>>> p.num_pages
2
>>> p.page_range
[1, 2]

>>> page1 = p.page(1)
>>> page1
<Page 1 of 2>
>>> page1.object_list
['john', 'paul']

Answer 3

T. Stone's answer covers most of what I was going to say. I just want to add that you can use pagination in Generic Views. In particular, you may find django.views.generic.list_detail.object_list useful.

You can write a small wrapper function that gets the number of objects to display per page from the request object, then calls object_list.

def paginated_object_list(request, page):

    my_queryset=MyModel.objects.all()
    #Here's T. Stone's code to get the number of items per page
    try:
        per_page = int(request.REQUEST['p'])
    except:
        per_page = 25     # default value

    return object_list(request, queryset=my_queryset, 
                                     paginate_by=per_page, page=page)

Then, the context for your template will contain the variables,

• paginator: An instance of django.core.paginator.Paginator.
• page_obj: An instance of django.core.paginator.Page.

and you can loop through page_obj to display the objects for that page.