问题
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 was, that the Project Structure was corrupt. e.g. missing imports from other files. But thats not the problem i think.
My models.py File:
from flask_login import UserMixin, LoginManager
from flaskapp import db, login_manager
@login_manager.user_loader
def get_user(user):
try:
return get_id(user)
except:
return None
class User(db.Model,UserMixin):
id =db.Column(db.Integer, primary_key=True)
username =db.Column(db.String(20),unique=True, nullable=False)
email =db.Column(db.String(120), unique=True, nullable=False)
password =db.Column(db.String(60), nullable=False)
powerlevel =db.Column(db.Integer, nullable=False)
def is_authenticated(self):
return True
def is_active(self):
return True
def is_anonymous(self):
return False
def get_id(self):
return int(self.id)
def __repr__(self):
return f"User('{self.username}', '{self.email}', '{self.powerlevel}')"
My init.py File:
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_bcrypt import Bcrypt
from flask_login import LoginManager
app = Flask(__name__)
app.config['SECRET_KEY'] = 'xxx'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///site.db'
db = SQLAlchemy(app)
bcrypt = Bcrypt(app)
login_manager = LoginManager(app)
login_manager.login_view = 'login'
login_manager = login_message_category = 'info'
from flaskapp import routes
When running the WebApp using:
export FLASK_APP=run.py DEBUG=TRUE flask run
Following Error Message Occurs:
Traceback (most recent call last):
File "/home/osboxes/.local/bin/flask", line 11, in <module>
sys.exit(main())
File "/home/osboxes/.local/lib/python3.6/site-packages/flask/cli.py", line 966, in main
cli.main(prog_name="python -m flask" if as_module else None)
File "/home/osboxes/.local/lib/python3.6/site-packages/flask/cli.py", line 586, in main
return super(FlaskGroup, self).main(*args, **kwargs)
File "/home/osboxes/.local/lib/python3.6/site-packages/click/core.py", line 717, in main
rv = self.invoke(ctx)
File "/home/osboxes/.local/lib/python3.6/site-packages/click/core.py", line 1137, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/osboxes/.local/lib/python3.6/site-packages/click/core.py", line 956, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/osboxes/.local/lib/python3.6/site-packages/click/core.py", line 555, in invoke
return callback(*args, **kwargs)
File "/home/osboxes/.local/lib/python3.6/site-packages/click/decorators.py", line 64, in new_func
return ctx.invoke(f, obj, *args, **kwargs)
File "/home/osboxes/.local/lib/python3.6/site-packages/click/core.py", line 555, in invoke
return callback(*args, **kwargs)
File "/home/osboxes/.local/lib/python3.6/site-packages/flask/cli.py", line 848, in run_command
app = DispatchingApp(info.load_app, use_eager_loading=eager_loading)
File "/home/osboxes/.local/lib/python3.6/site-packages/flask/cli.py", line 305, in __init__
self._load_unlocked()
File "/home/osboxes/.local/lib/python3.6/site-packages/flask/cli.py", line 330, in _load_unlocked
self._app = rv = self.loader()
File "/home/osboxes/.local/lib/python3.6/site-packages/flask/cli.py", line 388, in load_app
app = locate_app(self, import_name, name)
File "/home/osboxes/.local/lib/python3.6/site-packages/flask/cli.py", line 240, in locate_app
__import__(module_name)
File "/home/osboxes/Desktop/HMI/run.py", line 1, in <module>
from flaskapp import app
File "/home/osboxes/Desktop/HMI/flaskapp/__init__.py", line 21, in <module>
from flaskapp import routes
File "/home/osboxes/Desktop/HMI/flaskapp/routes.py", line 6, in <module>
from flaskapp.models import User
File "/home/osboxes/Desktop/HMI/flaskapp/models.py", line 7, in <module>
@login_manager.user_loader
AttributeError: 'str' object has no attribute 'user_loader'
Right now i don't know what else could be the problem. If i forgot to supply some code for solving the error, let me know. Thank you for your Help!
回答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'
回答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.
来源：https://stackoverflow.com/questions/58603924/attributeerror-object-has-no-attribute-user-loader