Django version 2.0 // A Few Key Features

   

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Hi, In this post from time to time as I uncover new things about Django version 2.0. This post will not be exhaustive since the release notes are.

Something else that's important to note: this post is mainly for our content. If you're randomly finding this, you might be wondering why we left out a few things. It's simple: the things below I know will have an immediate impact for our students looking to move to Django 2.0 (but remember always follow the version in the videos!) Enjoy.

New Starter page!

The image above, that's the new default starter page. Ahhh much better.

is_authenticated() is now is_authenticated

Example:

# < 2.0 
request.user.is_authenticated()

# 2.0

request.user.is_authenticated

reverse moved

# < 2.0 
from django.core.urlresolvers import reverse

# 2.0+
from django.urls import reverse

django.core.urlresolvers is now simply django.urls

on_delete is now required on Foreign Keys

#models.py

user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
updated_by = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.SET_NULL, null=True, Blank=True, related_name='update_user')

MIDDLEWARE_CLASSES in settings is just MIDDLEWARE now

Simplified URLs without REGEX

Both of the below accomplish the same result (and keyword argument):

from django.urls import re_path, path

from profiles.views import ProfileDetailView

urlpatterns = [
    ...
    re_path(r'^user/(?P<pk>\d+)/$', ProfileDetailView.as_view()),
    path('user/<int:pk>/', ProfileDetailView.as_view()),
    ...
]

Both of the below almost accomplish the same result (and keyword argument) as stated in the release notes:

from django.urls import re_path, path

from posts.views import YearArchive
urlpatterns = [
    ...
    re_path(r'^user/(?P<year>[0-9]{4})/$', YearArchive.as_view()),
    path('user/<int:year>/', YearArchive.as_view()),
]

The biggest difference between the year keyword arguments are the regex limits the allowed digits to 4, the other, will match any int

Namespacing

The reverse("<namespace>:<url-name>", kwargs={"<kwarg>": "<val>"}) method is great for building our urls.

In Django <= 1.11, we'd simply do:

# cfehome/urls.py 
urlpatterns = [
    url(r'^posts/', include('posts.urls', namespace='posts')) 
]

Notice the namespace keyword argument.

In Django 2.0+, we can just do:

# cfehome/urls.py
urlpatterns = [
    re_url(r'^posts/', include(('posts.urls', 'posts'))) 
]

Same thing is accomplished. We can even elminate that namespace variable all together by adding a new variable to urls.py in any given app. Such as:

# cfehome/urls.py
urlpatterns = [
    re_path(r'^posts/', include('posts.urls')) 
]

# posts/urls.py
from django.urls import re_path, path
from posts.views import YearArchive, ArchiveListView

app_name = 'posts'

urlpatterns = [
    ...
    re_path(r'^$', ArchiveListView.as_view(), name='archive-list'),
    re_path(r'^user/(?P<year>[0-9]{4})/$', YearArchive.as_view(), name='year-archive'),
    path('user/<int:year>/', YearArchive.as_view(), name='year-archive-path'),
]

Now, try to implement this using reverse and the url template tag

reverse("posts:archive-list")


reverse("posts:archive-list", kwargs={"year": 2017})



{% url "posts:archive-list" %}

{% url "posts:year-archive" year=2017 %}