AttributeError: Object Has No Attribute 'user_loader'

I'm programming a Website with Authentification while using the Flask Framework. I've tried every solution that i found on the internet but nothing worked for me. My first idea wa

Solution 1:

First, your User.get_id should be returning unicode not an int. The documentation mentions this, along with an example:

This method must return a unicode that uniquely identifies this user, and can be used to load the user from the user_loader callback. Note that this must be a unicode - if the ID is natively an int or some other type, you will need to convert it to unicode. (Your User Class)

So that needs to be changed to:

def get_id(self):
    return unicode(self.id)

Next up, your user_loader. From the docs:

This sets the callback for reloading a user from the session. The function you set should take a user ID (a unicode) and return a user object, or None if the user does not exist.

Which would mean adjusting your user_loader to be something like:

@login_manager.user_loader
def get_user(user_id):
    try:
        return User.query.get(int(user_id))
    except:
        return None

Also, you have an error here, which is likely the direct cause of the error:

login_manager = login_message_category = 'info'

So your taking your login_manager and replacing it with a string with the contents 'info'. So later when your app tries to access login_manager.user_loader it's failing, because a string 'info' doesn't have a user_loader method.

Changing it to the below should fix the error. Though the other issues addressed above also need to be implemented.

login_manager.login_message_category = 'info'

Solution 2:

You have used the login_manager = LoginManager(app) you are creating an object along with the configuration. Insider of that create an object first and configure the object in 2 steps.

login_manager = LoginManager()

login_manager.init_app(app)

for more reference please check the link here[https://flask-login.readthedocs.io/en/latest/]

you may need to update in your init.py file.