Back
Feb 28, 2010

Composing multiple views in Django

In UNIX way, each view should solve single task. This is good idea, but sometimes we need to mix logic of different views on same page. Filter, sort, paginate, or, for example, add comment on product page. In this article I'll show how we can mix such multiple views.

Idea

We can write views as decorators.

Example

Simplified filtration can look like this:

from django.views.generic.list_detail import object_list


def filtered_list(request, filterset_class, queryset, *args, **kwargs):
    filterset = filterset_class(request.GET)
    queryset = filterset.filter(queryset)
    kwargs['extra_context']['filterset'] = filterset

    return object_list(request, queryset, *args, **kwargs)

This is simple and straightforward, but in order to add some tricky pagination, we have to copy entire view and add more code to it.

Instead, we can create decorator like this:

def filtered(view):
    def wrapped(request, filterset_class, queryset, *args, **kwargs):
        filterset = filterset_class(request.GET)
        queryset = filterset.filter(queryset)
        kwargs['extra_context']['filterset'] = filterset
        return view(request, queryset, *args, **kwargs)

    return wrapped

Result

Assuming, that we have similar decorators, sorted и paginated, we can easily combine them:

@filtered
@paginated
def technic_list(*args, **kwargs):
    # ...

Or even like this, in lisp style:

url(r'^technic/$', filtered(sorted(paginated(object_list))), {
    'filterset_class': FilterSet,
     # ...
}, name='technic_list'),

Subscribe for the news and updates

More thoughts
Dec 13, 2022Technology
How to create a timelapse video from frames

We’ll tell you how to create a video timelapse from a sequence of snapshots and provide customers with video playlists optimized for browser playback.

Jun 14, 2017Technology
How to Deploy a Django Application on Heroku?

In this article I'll show you how to deploy Django with Celery and Postgres to Heroku.

Mar 12, 2017Technology
Creating a chat with Django Channels

Nowadays, when every second large company has developed its own instant messenger, in the era of iMessages, Slack, Hipchat, Messager, Google Allo, Zulip and others, I will tell you how to keep up with the trend and write your own chat, using django-channels 0.17.3, django 1.10.x, python 3.5.x.

Oct 22, 2016Technology
Solr Sharding

When dealing with one of our projects (LookSMI media monitoring platform) we have to handle the huge volume of data – and its quantity is constantly growing. At the same time, we must run quick searches with smart rules. In this article I'll explain how we have achieved required performance.

Oct 11, 2010Technology
Testing authentication in Django

In order to check if user is authentcated in test, you can run:

Feb 18, 2010Technology
Business logic in models

In my recent project there was a lot of data business logic, so I had to organize this code somehow. In this article I'll describe a few hints on how to it.