Implementing a Password Confirmation Flow with POST Requests

Your approach of using sessions to share data between views is on the right track, but there are a few issues with your current implementation. Let's refine it to properly handle the POST data flow and confirmation process.

Recommended Approach

Here's how you can implement this flow:

1. Store the form data in the session when confirmation is needed
2. Redirect to a password confirmation view
3. After successful confirmation, redirect back to the original view with a flag

BusinessView Implementation

PYTHONCopied
class BusinessView(FormView):
    template_name = 'business_form.html'
    form_class = BusinessForm
    
    def form_valid(self, form):
        cleaned_data = form.cleaned_data
        user = cleaned_data.get("user")
        
        # Safe case - no confirmation needed
        if service.user_safe_to_manager(user):
            return redirect(user)
            
        # Check if we're returning from password confirmation
        if self.request.session.get("password_confirmed"):
            # Clear the confirmation flag
            self.request.session.pop("password_confirmed", None)
            
            # Get the stored user from session
            user_to_promote = self.request.session.pop("user_to_promote", None)
            
            if user_to_promote:
                service.promote_to_manager(user=user_to_promote, by_user=self.request.user)
                return redirect(user_to_promote)
        
        # Store data in session and redirect to confirmation
        self.request.session['user_to_promote'] = user
        self.request.session['return_url'] = self.request.path
        
        return redirect('confirm_password')

ConfirmPassword View

PYTHONCopied
class ConfirmPasswordView(FormView):
    template_name = 'confirm_password.html'
    form_class = PasswordConfirmationForm
    
    def form_valid(self, form):
        # Mark as confirmed in session
        self.request.session['password_confirmed'] = True
        
        # Get the return URL from session
        return_url = self.request.session.get('return_url', '/')
        
        # Redirect back to the original view
        return redirect(return_url)

Password Confirmation Form

PYTHONCopied
class PasswordConfirmationForm(forms.Form):
    password = forms.CharField(widget=forms.PasswordInput)
    
    def __init__(self, *args, **kwargs):
        self.user = kwargs.pop('user', None)
        super().__init__(*args, **kwargs)
    
    def clean_password(self):
        password = self.cleaned_data.get('password')
        if not self.user.check_password(password):
            raise forms.ValidationError("Incorrect password")
        return password

URL Configuration

PYTHONCopied
urlpatterns = [
    # Your other URLs
    path('confirm-password/', views.ConfirmPasswordView.as_view(), name='confirm_password'),
    # ...
]

Key Improvements

1. You're returning a class instead of an instance in your original code (return views.ConfirmPassword.as_view()). This won't work - you need to redirect to a URL.

2. The session handling is more explicit, with proper cleanup of session variables.

3. The flow is clearer: store data → redirect to confirmation → confirm → redirect back with flag → process original action.

This approach preserves the POST data through the session while maintaining a clean separation between views. The user will see the password confirmation form as an intermediate step before completing the potentially disruptive action.