[PYTHON] [Django] I want to log in automatically after new registration

Introduction

New registration and login are the basic functions when creating a website. After completing the new registration, I wanted to omit the work of entering the necessary items on the login screen again, so I investigated the method.

Premise

The project structure is as follows. The setting directory is config, and the application directory is created in app and accounts.

.
├── accounts
│   ├── __init__.py
│   ├── admin.py
│   ├── apps.py
│   ├── forms.py
│   ├── migrations
│   ├── models.py
│   ├── tests.py
│   ├── urls.py
│   └── views.py
├── config
│   ├── __init__.py
│   ├── asgi.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
├── manage.py
├── app
│   ├── __init__.py
│   ├── apps.py
│   ├── forms.py
│   ├── migrations
│   ├── models.py
│   ├── tests.py
│   ├── urls.py
│   └── views.py
├── static
│   └── css   
│       └── style.css
└── templates
    ├── base.html
    ├── registration
    │   ├── base.html
    │   ├── logged_out.html
    │   ├── login.html
    │   └── signup.html
    └── app
        └── index.html

The settings directory, the URLconf in django.contrib.auth specified in it, and the URlconf in the application directory are shown below.

Configuration file URLconf

config/urls.py

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

urlpatterns = [
    path('admin/', admin.site.urls),
    path('', include('app.urls')),
    path('accounts/', include('django.contrib.auth.urls')),  #Urls provided by Django in advance.To py
    path('accounts/', include('accounts.urls')),  #Urls I created.To py
]

django/contrib/auth/urls.py

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

urlpatterns = [
    path('login/', views.LoginView.as_view(), name='login'),
    path('logout/', views.LogoutView.as_view(), name='logout'),

    path('password_change/', views.PasswordChangeView.as_view(), name='password_change'),
    path('password_change/done/', views.PasswordChangeDoneView.as_view(), name='password_change_done'),

    path('password_reset/', views.PasswordResetView.as_view(), name='password_reset'),
    path('password_reset/done/', views.PasswordResetDoneView.as_view(), name='password_reset_done'),
    path('reset/<uidb64>/<token>/', views.PasswordResetConfirmView.as_view(), name='password_reset_confirm'),
    path('reset/done/', views.PasswordResetCompleteView.as_view(), name='password_reset_complete'),
]

Application URLconf

app/urls.py

from django.urls import path
from . import views

app_name = 'app'
urlpatterns = [
    path('', views.IndexView.as_view(), name='index'),
]

accounts/urls.py

from django.urls import path
from . import views

app_name = 'accounts'
urlpatterns = [
    path('signup/', views.SignUpView.as_view(), name='signup'),
]

Main subject

New registration completed → Enter on the login screen → Login completed

First, check the state before mounting.

accounts/views.py

from django.urls import reverse_lazy
from django.views import generic

from .forms import UserCreateForm


class SignUpView(generic.CreateView):
    form_class = UserCreateForm
    template_name = 'registration/signup.html'
    success_url = reverse_lazy('login')

• Create a SignUpView that inherits CreateView.
• form_class = Specify the form to be handled by UserCreateForm. This time, specify UserCreateForm created by app / forms.py as form_class.
• Specify the html file of the new registration screen with template_name ='registration / signup.html'.
• Use reverse_lazy to specify which page to go to after new registration is completed with success_url = reverse_lazy ('login'). In this case, it's'login', so when new registration is complete, you'll be taken to the login page (registration / login.html) that Django has prepared in advance.
• Specify the html file of the new registration screen with template_name ='registration / signup.html'. (* The html of the login page is prepared in advance, but the new registration screen is not prepared, so you need to create it yourself.)

New registration completed → Login completed

After the new registration is completed, you only need to make a small change to acccouts / views.py to complete the login without going through the login screen.

accounts/views.py

from django.urls import reverse_lazy
from django.views import generic
from django.contrib.auth import login, authenticate    #add to

from .forms import UserCreateForm


class SignUpView(generic.CreateView):
    form_class = UserCreateForm
    success_url = reverse_lazy('app:index')   #Change
    template_name = 'registration/signup.html'

    #Added below
    def form_valid(self, form):
        response = super().form_valid(form)
        username = form.cleaned_data.get('username')
        password = form.cleaned_data.get('password1')
        user = authenticate(username=username, password=password)
        login(self.request, user)
        return response

There are two tasks to do: specifying success_url and overriding the form_valid method.

• Use success_url = reverse_lazy ('app: index') to change the screen that transitions after registration is completed from'login'to'app: index', that is, the top page.
• Add code that overrides the form_valid method.
• Get the value returned by the parent form_valid () with response = super (). form_valid (form).
• ʻUsername = form.cleaned_data.get ('username')and substitute the value entered in the newly registered userneme field for username.form.cleaned_data` indicates the data that passed the input validation.
• The same is true for password = form.cleaned_data.get ('password1').
• ʻUser = authenticate (username = username, password = password) to authenticate a user and password. ʻAuthenticate () takes a username and password as arguments and returns a User object if the password is valid for the username. If it is invalid, None is returned.
• Automatically log in the user with login (self.request, user). login () takes an HttpRequest object and a User object as arguments.
• Finally returns a response.