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Chapter 19

Updates

Updates for Django 2.1

In Django 2.1, there is a slight change to the way user authentication is handled. This affects the way URLs in the users app are structured, and it affects the /users/views.py file as well.

p. 440, The Login Page

The /users/urls.py file should look like this:

"""Defines url patterns for users."""

from django.urls import path
from django.contrib.auth import views as auth_views

from . import views

app_name = 'users'
urlpatterns = [
	# Login page.
    path('login/',
    	auth_views.LoginView.as_view(template_name='users/login.html'),
    	name='login'),
]

There are two differences here. We’re importing a set of views from django.contrib.auth, as auth_views. Also, the path to the login view is structured differently, to use the default class-based view for logins, LoginView. In order to use our own login template, we provide the template_name argument in the call to the default view.

p. 442, The logout URL

The /users/urls.py file should look like this:

"""Defines url patterns for users."""

from django.urls import path
from django.contrib.auth import views as auth_views

from . import views

app_name = 'users'
urlpatterns = [
	# Login page.
    path('login/',
    	auth_views.LoginView.as_view(template_name='users/login.html'),
    	name='login'),

    # Logout page.
    path('logout/', auth_views.LogoutView.as_view(), name='logout'),
]

Again, the logout view uses the default class-based LogoutView. We don’t need to pass a template name, because there is no template for logging out.

p. 442-443, The logout_view() View Function

In Django 2.1 there is no need for a logout view, so ignore what you see in this section in the book. Instead, we’ll use a setting called LOGOUT_REDIRECT_URL in settings.py. It doesn’t really matter where this setting goes, but I like to put it in a section at the end of the file labeled # My settings:

--snip--
# My settings
LOGOUT_REDIRECT_URL = '/'

This tells Django what page to redirect the user to when they click the logout link. After adding this setting to settings.py, move on to the section Linking to the logout View.

p. 444, The register() View Function

Nothing has really changed about the way the register page is built. The only thing to note here is that the django.contrib.auth import line will look slightly different in Django 2.1, because we don’t need to import the logout function. The import statement will look like this:

from django.contrib.auth import login, authenticate

Updates for Django 2.0

p. 429, The new_topic URL

The new_topic URL pattern should look like this:

urlpatterns = [
    --snip--
    # Page for adding a new topic.
    path('new_topic/', views.new_topic, name='new_topic'),
]

The new_topic() View Function

The reverse() function has been moved to a different module, so its import statement has changed:

from django.shortcuts import render
from django.http import HttpResponseRedirect
from django.urls import reverse

p. 433, The new_entry URL

The new_entry URL pattern should look like this:

urlpatterns = [
    --snip--
    # Page for adding a new entry.
    path('new_entry/<int:topic_id>/', views.new_entry, name='new_entry'),
]

p. 436, The edit_entry URL

The edit_entry URL pattern should look like this:

urlpatterns = [
    --snip--
    # Page for editing an entry.
    path('edit_entry/<int:entry_id>/', views.edit_entry, name='edit_entry'),
]

p. 439, Including the URLs from users

The line to include the URLs from the users app should look like this:

from django.urls import path, include
from django.contrib import admin

urlpatterns = [
    path('admin/', admin.site.urls),
    path('users/', include('users.urls')),
    path('', include('learning_logs.urls')),
]

As we saw when including the URLs from learning_logs, we write a simple string for the base of the URL, 'users/'. We leave out the namespace argument, because the namespace will be defined in the users/urls.py file.

p. 440, The Login Page

The users/urls.py file should look like this:

"""Defines url patterns for users."""

from django.urls import path
from django.contrib.auth.views import login

from . import views

app_name = 'users'
urlpatterns = [
    # Login page.
    path('login/', login, {'template_name': 'users/login.html'},
        name='login'),
]

Here we’ve defined the app_name variable, which defines the namespace for the URLs associated with the users app. We’ve also used the path() function to define the URL pattern for the login page.

p. 442, The logout URL

The logout URL pattern should look like this:

urlpatterns = [
    --snip--    
    # Logout page.
    path('logout/', views.logout_view, name='logout'),
]

p. 442-3, The logout_view() View Function

In users/views.py, the reverse() function needs to be imported from django.urls:

from django.urls import reverse

p. 444, The register URL

The register URL should look like this:

urlpatterns = [
    --snip--    
    # Registration page.
    path('register/', views.register, name='register'),
]

p. 449, Modifying the Topic Model

In learning_logs/models.py, the line that defines the foreign key relationship between topics and users should look like this:

owner = models.ForeignKey(User, on_delete=models.CASCADE)

This tells Django that when a user is deleted, all of the topics owned by that user should be deleted as well.