[Flask] Stuck with @login_required which breaks our app

[David Nieder]

Hello Stefan,

I took your code and put together a minimal example but I could not
reproduce your error: the redirect always happens for me.
Looking at the code of Flask-Login, it seems to me that the only time
401 is returned is if login_view is not set. Maybe look at that
again? But with your other dependencies there could be more going on.

So the only tip I can give is: check if Flask-Login works with a
stripped-down version of your code and add components back in.
Here is what I used:

from flask import Flask, request
from flask_login import LoginManager, login_required, current_user,
UserMixin

app = Flask(__name__)
app.secret_key = '123456'

login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = 'login'


@login_manager.user_loader
def load_user(user_id):
   return UserMixin

@app.route('/index')
def index():
   return 'the index page'

@app.route('/contents')
@login_required
def contents():
   return 'the content page'

@app.route('/login', methods=['GET', 'POST'])
def login():
   if not current_user.is_authenticated:
     return 'current_user not authenticated'
   return 'current_user authenticated'



Good luck
David

P.S. there is flask community on discord which is a lot more active than
this list. Maybe you can find more help there.
https://discord.gg/pallets



On 24.02.22 09:49, Stefan Knecht wrote:
 > Hello all
 >
 > I'm hoping to end a week-long struggle by reaching out here.
 >
 > We've been evaluating and testing building flask apps to give our vast
 > python command line tool arsenal a face lift.
 >
 > I've got the basics working with coreUI for templates and flask doing the
 > core functionality. Or well, so it should.
 >
 > I've been following tutorials and the documentation, and as far as I can
 > tell, we're doing everything correctly - yet it doesn't work anymore, as
 > soon as I make use of @login_required.
 >
 > This is our routes.py:
 >
 > from app.home import blueprint
 > from app.base.forms import LoginForm, CreateAccountForm
 >
 > from flask import Flask, current_app, render_template, redirect, url_for,
 > request, jsonify, session
 > from flask_login import LoginManager, login_required, current_user,
 > login_user, logout_user
 >
 > from app import login_manager
 > from app.base.models import User
 >
 > app = Flask(__name__)
 >
 > login_manager = LoginManager()
 > login_manager.init_app(app)
 > login_manager.login_view = 'home_blueprint.login'
 >
 >
 > @login_manager.user_loader
 > def load_user(user_id):
 >    print(f"User loader {user_id}")
 >    return User.get(user_id)
 >
 > @blueprint.route('/index')
 > def index():
 >    print("Index")
 >    return render_template('index.html')
 >
 > @blueprint.route('/contents')
 > @login_required
 > def contents():
 >    print("Contents")
 >    return ('hello', 200)
 >
 >
 > @blueprint.route('/login', methods=['GET', 'POST'])
 > def login():
 >
 >    print(f"HEADER {request.headers}")
 >
 >    login_form = LoginForm(request.form)
 >    if 'login' in request.form:
 >
 >      # read form data
 >      username = request.form['username']
 >      password = request.form['password']
 >
 >
 >    if not current_user.is_authenticated:
 >      return render_template( 'accounts/login.html', form=login_form)
 >    return redirect(url_for('home_blueprint.index'))
 >
 > If I remove @login_required from the /contents route, everything works
 > fine. As soon as I add it there (or anywhere else for that matter) we get
 > nothing but 401 Unauthorized.
 >
 > This is what we use:
 >
 > $ pip3 list | grep -i flask
 > Flask                  1.1.1
 > Flask-Bootstrap        3.3.7.1
 > Flask-Ext              0.1
 > flask-ldap-login       0.3.0
 > flask-ldap3-login      0.9.16
 > Flask-Login            0.5.0
 > Flask-Migrate          2.5.3
 > flask-nav              0.6
 > Flask-Session          0.3.2
 > Flask-SimpleLDAP       1.4.0
 > Flask-SQLAlchemy       2.4.4
 > Flask-WTF              0.14.3
 >
 > Any hint would be greatly appreciated. The head hurts, the wall's already
 > got a big hole in it.
 >
 >
 > Stefan
 >
 >
 > _______________________________________________
 > Flask mailing list
 > Flask at python.org
 > https://mail.python.org/mailman/listinfo/flask