Ordering Django Reverse

Django Reverse is a powerful tool for generating URLs for views, but sometimes we need to order the query parameters that we pass with it. In this article, we will examine how to use Django's reverse function to generate ordered URLs.

Overview

Django's reverse function is used to generate a URL for a given view function or URL pattern name. For example, let's say we have the following URL pattern in our urls.py file:

from django.urls import path

from . import views

urlpatterns = [
    path('blog/<int:year>/<int:month>/<str:slug>/', views.blog_detail, name='blog_detail'),
]

We can use reverse to generate an URL for this view:

from django.urls import reverse

url = reverse('blog_detail', args=[2021, 10, 'ordering-django'])

However, by default, reverse generates URLs without any ordering of query parameters. For example, the above code would generate the following URL:

/blog/2021/10/ordering-django/

If we want to order the query parameters in the generated URL, we can use the QueryDict class from Django's django.http module.

Ordering Query Parameters

Let's assume we want to order the query parameters alphabetically when generating the URL. We can achieve this by sorting the dictionary of query parameters before building the query string.

from django.urls import reverse
from django.http import QueryDict

params = {'page': 1, 'date': 'asc', 'search': 'django'}

# Create a QueryDict instance from the dictionary and sort it
query_dict = QueryDict('', mutable=True)
for key, value in sorted(params.items()):
    query_dict.appendlist(key, value)

url = reverse('blog_list') + '?' + query_dict.urlencode()

In the above code, we first create a QueryDict instance from the dictionary of query parameters. We then sort the items in the dictionary by key and append each key-value pair to the QueryDict instance. Finally, we use urlencode to build the query string and append it to the reversed URL.

Conclusion

In this article, we have examined how to use Django's reverse function to generate ordered URLs. By using Django's QueryDict class, we can easily order the query parameters that we pass with the reverse function. This can be useful when building URLs for pagination and filtering, among other use cases.