Flask-Login : login.py created by https://github.com/maxcountryman : Matthew Frazier

login-example

# -*- coding: utf-8 -*-
"""
Flask-Login example
===================
This is a small application that provides a trivial demonstration of
Flask-Login, including remember me functionality.

:copyright: (C) 2011 by Matthew Frazier.
:license:   MIT/X11, see LICENSE for more details.
"""
from flask import Flask, request, render_template, redirect, url_for, flash
from flask.ext.login import (LoginManager, current_user, login_required,
                            login_user, logout_user, UserMixin, AnonymousUser,
                            confirm_login, fresh_login_required)

class User(UserMixin):
    def __init__(self, name, id, active=True):
        self.name = name
        self.id = id
        self.active = active

    def is_active(self):
        return self.active


class Anonymous(AnonymousUser):
    name = u"Anonymous"


USERS = {
    1: User(u"Notch", 1),
    2: User(u"Steve", 2),
    3: User(u"Creeper", 3, False),
}

USER_NAMES = dict((u.name, u) for u in USERS.itervalues())


app = Flask(__name__)

SECRET_KEY = "yeah, not actually a secret"
DEBUG = True

app.config.from_object(__name__)

login_manager = LoginManager()

login_manager.anonymous_user = Anonymous
login_manager.login_view = "login"
login_manager.login_message = u"Please log in to access this page."
login_manager.refresh_view = "reauth"

@login_manager.user_loader
def load_user(id):
    return USERS.get(int(id))


login_manager.setup_app(app)

@app.route("/")
def index():
    return render_template("index.html")


@app.route("/secret")
@fresh_login_required
def secret():
    return render_template("secret.html")


@app.route("/login", methods=["GET", "POST"])
def login():
    if request.method == "POST" and "username" in request.form:
        username = request.form["username"]
        if username in USER_NAMES:
            remember = request.form.get("remember", "no") == "yes"
            if login_user(USER_NAMES[username], remember=remember):
                flash("Logged in!")
                return redirect(request.args.get("next") or url_for("index"))
            else:
                flash("Sorry, but you could not log in.")
        else:
            flash(u"Invalid username.")
    return render_template("login.html")


@app.route("/reauth", methods=["GET", "POST"])
@login_required
def reauth():
    if request.method == "POST":
        confirm_login()
        flash(u"Reauthenticated.")
        return redirect(request.args.get("next") or url_for("index"))
    return render_template("reauth.html")


@app.route("/logout")
@login_required
def logout():
    logout_user()
    flash("Logged out.")
    return redirect(url_for("index"))

if __name__ == "__main__":
    app.run()

this example doesn't work. Throws ImportError: cannot import name LoginManager.

@ajaykgp :

from flaskext.login import should be from flask.ext.login import.....

Then it will work !!

Thank you, This totally helped me out. I appreciate it.

@ajaykgp Sorry for the Typo Error

I have been trying to figure out when and where to override is_authenticated() from the UserMixin. Anytime I try to override it and use an in-object property I always end up with a User that has an authenticated property value of False in subsequent uses, even when I set it to True. Is there something I need to do to ensure the session remembers the user object I am updating?

Here is the User object:

class User(UserMixin):
    def __init__(self, username='', email='',
                 uid=None, standing='good', active=False,
                 confirmed_at=dt.MAXYEAR, created=None):
        super(User, self).__init__()
        self.username = str(username)
        self.email = email
        self.active = active
        self._authenticated = False

    def is_active(self):
        return self.active

    def set_authenticated(self, value):
        if value:
            self._authenticated = True

    def is_authenticated(self):
        return self._authenticated

...and then in a pared down snippet of code, here's where I set the authenticated property to True

@app.route('/v1/user/login', methods=['POST', 'OPTIONS'])
def login():
    u = json.loads(request.data)
    user = datastore.get_user(u['username'])

    if user.check_password(u['password']):
        user.set_authenticated(True) # <<< here is where the value should become True
        if login_user(user, remember=remember):
            return make_response(jsonify(username=u['username'],
                                                 last_login=user.last_login,
                                                 message='Login successful'), 200)

Shouldn't AnonymousUser be AnonymousUserMixin ?

Sorry I'm new to flask... how do I install flask.ext.login ?
My OS is ubuntu... flask itself is working. but not this one. thanks.

sudo easy_install flask.ext.login

Searching for flask.ext.login
Reading http://pypi.python.org/simple/flask.ext.login/
Couldn't find index page for 'flask.ext.login' (maybe misspelled?)
Scanning index of all packages (this may take a while)

@victorfang If you haven't got it installed yet, try 'sudo easy_install Flask-Login'

@jamespo
They changed the AnonymousUser name to AnonymousUserMixin, see pallets-eco/flask-security#119

Hi! Thanks for this! Anyone know where I can find the corresponding .html files etc? Is this part of a full package somewhere else?

Thanks for this! I was seriously struggling with the User class as almost every tutorial forces you to use sqlalchemy for the database. The way you did it made so much more sense.

Here's actual code (April 2024). You just need to add simple index.html, secret.html ,etc

# -*- coding: utf-8 -*-
"""
Flask-Login example
===================
This is a small application that provides a trivial demonstration of
Flask-Login, including remember me functionality.

:copyright: (C) 2011 by Matthew Frazier.
:license:   MIT/X11, see LICENSE for more details.
"""
from flask import Flask, request, render_template, redirect, url_for, flash
from flask_login import (LoginManager, current_user, login_required,
                         login_user, logout_user, UserMixin,
                         confirm_login, fresh_login_required)


class User(UserMixin):
    def __init__(self, name, id1, active=True):
        self.name = name
        self.id = id1
        self.active = active

    def is_active(self):
        return self.active


class AnonymousUser(UserMixin):
    name = "Anonymous"
    id = None
    active = False


class Anonymous(AnonymousUser):
    name = "Anonymous"


USERS = {
    1: User("Notch", 1),
    2: User("Steve", 2),
    3: User("Creeper", 3, False),
}

USER_NAMES = {u.name: u for u in USERS.values()}  # Uwaga: metoda .itervalues() jest przestarzała w Python 3.x

app = Flask(__name__)

SECRET_KEY = "yeah, not actually a secret"
DEBUG = True

app.config.from_object(__name__)

login_manager = LoginManager()
login_manager.init_app(app)

login_manager.anonymous_user = Anonymous
login_manager.login_view = "login"
login_manager.login_message = "Please log in to access this page."
login_manager.refresh_view = "reauth"


@login_manager.user_loader
def load_user(user_id):
    return USERS.get(int(user_id))


@app.route("/")
def index():
    return render_template("index.html")


@app.route("/secret")
@fresh_login_required
def secret():
    return render_template("secret.html")


@app.route("/login", methods=["GET", "POST"])
def login():
    if request.method == "POST" and "username" in request.form:
        username = request.form["username"]
        if username in USER_NAMES:
            remember = request.form.get("remember", "no") == "yes"
            if login_user(USER_NAMES[username], remember=remember):
                flash("Logged in!")
                return redirect(request.args.get("next") or url_for("index"))
            else:
                flash("Sorry, but you could not log in.")
        else:
            flash("Invalid username.")
    return render_template("login.html")


@app.route("/reauth", methods=["GET", "POST"])
@login_required
def reauth():
    if request.method == "POST":
        confirm_login()
        flash("Reauthenticated.")
        return redirect(request.args.get("next") or url_for("index"))
    return render_template("reauth.html")


@app.route("/logout")
@login_required
def logout():
    logout_user()
    flash("Logged out.")
    return redirect(url_for("index"))


if __name__ == "__main__":
    app.run(debug=True)