Django Success URL Gets Appended To Middleware Redirect URL Instead of Redirecting To Success URL

Question

I have a form with a username field on it located at /accounts/choose-username/.

views.py

from django.views.generic import FormView

from .forms import ChooseUsernameForm
from django.contrib.auth import get_user_model

User = get_user_model()

class ChooseUsernameView(FormView):

    template_name = 'registration/choose-username.html'
    form_class = ChooseUsernameForm
    success_url = 'accounts/profile/' # <-------------

    def form_valid(self, form):
        """If the form is valid, redirect to the supplied URL."""
        print(form.cleaned_data['username'])
        print(self.request.user)
        user = User.objects.get(email=self.request.user)
        user.username = form.cleaned_data['username']
        user.save()
        return super().form_valid(form)

middleware.py

from django.shortcuts import redirect, reverse

class SimpleMiddleware:
    def __init__(self, get_response):
        self.get_response = get_response
        # One-time configuration and initialization.

    def __call__(self, request):
        # Code to be executed for each request before
        # the view (and later middleware) are called.

        response = self.get_response(request)
        if request.user.is_authenticated:
            if request.user.username is None:
                print(request.path)
                if not request.path == reverse('choose_username'):
                    return redirect(reverse('choose_username'))

        return response

When I submit the form, my url is accounts/choose-username/accounts/profile/

I want it to be accounts/profile/

MIDDLEWARE settings.py looks like this:

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'accounts.middleware.SimpleMiddleware', #           <---
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

My Question

Why does my success URL get appended to my accounts/choose-username/ URL? How can I fix it?

Answer 1

As this—accounts/profile/—doesn't start with a slash (/), so it is a relative path. Browsers automatically append the relative path to the current page's url.

You need to use absolute path (add slash in the beginning).

success_url = '/accounts/profile/'