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
Apr 3, 2024Technology
Test Analysis at the Product Level

Test analysis is an essential and crucial activity in the testing process. A well-organized test analysis provides an adequate level of confidence in the overall effectiveness of the testing and contributes to the delivery of high-quality software.

Sep 8, 2023Technology
Smooth React virtual scroll with fixed rows/columns

One of our ongoing projects, Neptyne, introduces an Excel-like grid written in React. We used a library to apply virtual scroll to it, but we stumbled upon a problem with fixed rows and columns inside the grid. Here I would like to describe this problem, how it occurs, and how we handled it.

May 5, 2023Technology
The best CSS trends for 2023

Cascading Style Sheets (CSS) made its debut in 1996 and continue to be an indispensable and evolving component of web development. We will examine the most valuable recent and upcoming characteristics in CSS for this year.

May 26, 2017Technology
Tutorial: Django User Registration and Authentication

In this beginners friends article I'll explain how to make authentication with Google account on your Django site and how to make authentication for you REST API.

Aug 8, 2016TechnologyBusiness
How To Add HTML5 Geolocation To Your Web App?

In this article I will describe how to integrate geolocation HTML5 function to a web app so you can then easily implement it in your apps or websites. As an example we are going to create small web app which will be able to calculate the shortest route between detected user’s location and predefined destination using Google Maps API.

Apr 3, 2011Technology
Sprite cache invalidation

When we use css-sprites it's important to make browser cache them for longest period possible. On other hand, we need to refresh them when they are updated. This is especially visible when all icons are stored in single sprite. When it's outdated - entire site becomes ugly.