UserCreationForm, hash password and authenticate()

Question

I am new to Django and i'm trying create simple user registration/login app. For registration I'm using custom UserCreationForm:

def registration(request):
    if request.method == 'POST':
        form = UserCreationForm(request.POST)
        if form.is_valid():
            new_user = form.save()
            messages.info(request, "You've successfully registered")
            return HttpResponseRedirect('/')
    else:
        form = UserCreationForm
    return render(request, 'accounts/registration.html', {'form': form})

And it works well. But writing login function I faced with difficulties. I've got AttributeError at /accounts/login 'User' object has no attribute 'backend'. It seems that authenticate() returns None object even when login/password correct.

def login(request):
    if request.method == "POST":
        form = LoginForm(request.POST)
        if form.is_valid():
            userData = form.cleaned_data
            user = authenticate(username=userData['username'],password=userData['password'])
            auth_login(request, user)
            messages.info(request, "You're successfully logged in")
            return HttpResponseRedirect('/')
        else:
            messages.info(request, 'Invalid username or password')
            return HttpResponseRedirect('/accounts/login')
    else:
        form = LoginForm() 
    return render(request, 'accounts/login.html', {'form': form}

I think the point is that password saved in DB in hashed form and that's why userData['password'] not identical to value in db for the same username.

What i the best way to fix this bug?

Trace error

Internal Server Error: /accounts/login
Traceback (most recent call last):
  File "C:\Python27\myproject\djcode\first_venv\venv\lib\site-packages\django\core\handlers\base.py"
, line 115, in get_response
    response = callback(request, *callback_args, **callback_kwargs)
  File "C:\Python27\myproject\djcode\first_venv\myownproject\accounts\views.py", line 36, in login
    auth_login(request, user)
  File "C:\Python27\myproject\djcode\first_venv\venv\lib\site-packages\django\contrib\auth\__init__.
py", line 92, in login
    request.session[BACKEND_SESSION_KEY] = user.backend
  File "C:\Python27\myproject\djcode\first_venv\venv\lib\site-packages\django\utils\functional.py",
line 203, in inner
    return func(self._wrapped, *args)
AttributeError: 'User' object has no attribute 'backend'

Answer 1

try this in your code

user = authenticate(username=userData['username'],password=userData['password'])
if user:
    user.backend = 'django.contrib.auth.backends.ModelBackend'
    auth_login(request, user)
else:
    print "invalid login"