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.

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 9, 2018Technology
How to Generate PDF Files in Python with Xhtml2pdf, WeasyPrint or Unoconv

Programmatic generation of PDF files is a frequent task when developing applications that can export reports, bills, or questionnaires. In this article, we will consider three common tools for creating PDFs, including their installation and converting principles.

Nov 21, 2016Technology
Crawling FTP server with Scrapy

Welcome all who are reading this article. I was given a task of creating a parser (spider) with the Scrapy library and parsing FTP server with data. The parser had to find lists of files on the server and handle each file separately depending on the requirement to the parser.

May 12, 2010Technology
Twitter API, OAuth and decorators

In my current project I had a task to use twitter API. Twitter uses OAuth for authentication, which is pretty dreary. To avoid fiddling with it all the time, I've moved authentication to decorator. If key is available - nothing happens, just view is launched as usual. It's convenient that there's no need for additional twitter settings in user profile. Code is in article.

Feb 18, 2010Technology
User profiles with inheritance in Django

Usually users' profiles are stored in single model. When there are multiple user types, separation is made by some field like user_type.Situation is a little more complicated when different data is needed for each user type.In this article I'll describe how I solve this task.