Django - Login with email or username not working

Question

In my project, I implement a login system where a user can login using their username or their email. I basically try to find whether a users email is inserted into the form field "usernameOrEmail" or whether it is their username entered in the "usernameOrEmail" field. I then log them in if a user is found.

Here is my code:

def login(request):
    context = {}
    if request.method == "POST":
        isFound = ""
        form = LoginForm(request.POST)
        if form.is_valid():
            try:
                user = User.objects.get(username=form.cleaned_data.get("usernameOrEmail"))
                isFound = "usernameFound"
            except User.DoesNotExist:
                try:
                    user = User.objects.get(email=form.cleaned_data.get("usernameOrEmail"))
                    isFound = "emailFound"
                except User.DoesNotExist:
                    isFound = "nothingFound"




            if isFound == "usernameFound":
                print("USERNAME FOUND!")
                user = auth.authenticate(username=form.cleaned_data.get("usernameOrEmail"), password=form.cleaned_data.get("password"))
                if user is not None:
                    auth.login(request, user)
                    return redirect('home')
                else:
                    context["error"] = "Oops, username/email or password provided is invalid"
            elif isFound == "emailFound":
                print("EMAIL FOUND")
                user = auth.authenticate(email=form.cleaned_data.get("usernameOrEmail"), password=form.cleaned_data.get("password"))
                if user is not None:
                    print("YES")
                    auth.login(request, user)
                    return redirect('home')
                else:
                    print("NO")
                    context["error"] = "Oops, username/email or password provided is invalid"
            else:
                context["error"] = "Oops, username/email or password provided is invalid"
        else:
            context["error"] = "Please enter valid form data"
    else:
        form = LoginForm()

Weirdly, the terminal return the print statement "EMAIL FOUND" meaning that the email of a user was found, however the "NO" print statement is also printed, and the message "Oops, username/email or password provided is invalid" is returned in the template.

The other weird thing is that this system works for the users username, meaning when I enter a users username into the "usernameOrEmail" field, and I enter the correct password, the user is logged in. Anybody know the issue? thank you.

Answer 1

The standard authentication backend only works with a username and password . Indeed, the authenticate method [GitHub] of the ModelBackend is implemented as:

 def authenticate(self, request,  , password=None, **kwargs): if username is None: username = kwargs.get(UserModel.USERNAME_FIELD) if username is None or password is None: return try: user = UserModel._default_manager.get_by_natural_key(username) except UserModel.DoesNotExist: # Run the default password hasher once to reduce the timing # difference between an existing and a nonexistent user (#20760). UserModel().set_password(password) else: if user.check_password(password) and self.user_can_authenticate(user): return user

This is however not a problem. You can just implement this with:

def login(request):
    context = {}
    if request.method == 'POST':
        form = LoginForm(request.POST)
        if form.is_valid():
            try:
                user = User.objects.get(username=form.cleaned_data['usernameOrEmail'])
            except User.DoesNotExist:
                try:
                    user = User.objects.get(email=form.cleaned_data['usernameOrEmail'])
                except User.DoesNotExist:
                    user = None
            if user is not None:
                user = auth.authenticate(username=, password=form.cleaned_data['password'])
            if user is not None:
                auth.login(request, user)
                return redirect('home')
            else:
                context['error'] = 'Oops, username/email or password provided is invalid'
        else:
            context['error'] = 'Please enter valid form data'
    else:
        form = LoginForm()
    # …