How to create a DB Model for Anonymous users? - python

I have created a web app using Flask where you can leave a note as text. Ig goes well you leave a text and it got saved in our database. But it only happens when you are an authorized user and can't be done if you are an unauthorized (anonymous user) and if you attempt as such this error message pops up: "'AnonymousUserMixin' object has no attribute 'id'".
Here the code goes:
#home.py
def home():
if request.method == 'POST':
note = request.form.get('note')
if len(note) < 1:
flash('Note is too short!', category='error')
else:
new_note = Note(data=note, user_id=current_user.id)
db.session.add(new_note)
db.session.commit()
flash('Note added!', category='success')
return render_template("home.html", user=current_user)
And the DB models:
#models.py
class Note(db.Model):
id = db.Column(db.Integer, primary_key=True)
data = db.Column(db.String(10000))
date = db.Column(db.DateTime(timezone=True), default=func.now())
user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
class User(db.Model, UserMixin):
id = db.Column(db.Integer, primary_key=True)
email = db.Column(db.String(150), unique=True)
password = db.Column(db.String(150))
first_name = db.Column(db.String(150))
confirmed = db.Column(db.Boolean, nullable=False, default=False)
notes = db.relationship('Note')

You are setting a user_id value when creating a Note:
new_note = Note(data=note, user_id=current_user.id)
Evidently anonymous users don't have an id attribute, so you must either set user_id=None when creating notes for anonymous users or create a default user to represent anonymous users and user that user's id when creating notes.

Related

Creating parent and child at the same time. Flask SqlAlchemy

I have created the model below to store user and profile data separately in my database
class User(db.Model):
__tablename__ = "user"
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(40), unique=True)
password = db.Column(db.String(255))
profile = db.relationship('Profile', backref='Profile', uselist=False)
class Profile(db.Model):
id = db.Column(db.Integer, primary_key=True)
first_name = db.Column(db.String(25))
last_name = db.Column(db.String(25))
email = db.Column(db.String(25), unique=True)
phone_number = db.Column(db.String(25), unique=True)
post_code = db.Column(db.String(25))
house_number = db.Column(db.String(25))
user = db.Column(db.Integer, db.ForeignKey('user.id'))
I have attempted to populate Profile Model via this method, however, it does not work.
#routes.route('/register', methods = ['POST'])
def register():
if request.method == 'POST':
data = request.get_json()
new_user = User(username = data['username'], password = data['password'])
new_user.profile.first_name = data['first_name']
new_user.profile.last_name = data['last_name']
new_user.profile.email = data['email']
new_user.profile.phone_number = data['phone_number']
new_user.profile.post_code = data['post_code']
new_user.profile.house_number = data['house_number']
db.session.add(new_user)
db.session.commit()
return {'msg' : 'sucess'}
I get this error, would you please explain what I am doing wrong? I noticed that User.profile column is not present inside my database, however, I thought that was normal for a ForiegnKey?
File "C:\routes\register.py", line 11, in register
new_user.profile.first_name = data['first_name']
AttributeError: 'NoneType' object has no attribute 'first_name'
What is the solution ? I am assuming I need to create Profile() model separately but how do I simultaneously link that to an uncommitted User() model?
A few ways to do this, but you probably want to create an __init__(...) for user where you initialize a Profile object.
Something like this...
class User(db.Model):
__tablename__ = "user"
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(40), unique=True)
password = db.Column(db.String(255))
profile = db.relationship('Profile', backref='Profile', uselist=False)
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.profile = Profile()

I have a confusion using backref in Flask SQLAlchemy database tables

models.py
#login_manager.user_loader
def load_user(username):
return User.query.get(username)
class User(db.Model,UserMixin):
__tablename__ = 'user_accounts'
id = db.Column(db.Integer,primary_key=True)
username = db.Column(db.String(50),unique=True, nullable=False)
email = db.Column(db.String(120), unique=True, nullable=False)
image_file = db.Column(db.String(20),default='default.jpg')
password = db.Column(db.String(80), nullable=False)
task = db.relationship('Tasks', backref='author', lazy=True)
def __repr__(self):
return f'User <{self.id}> {self.username}'
class Tasks(db.Model):
__tablename__ = 'tasks'
id = db.Column(db.Integer,primary_key=True)
title = db.Column(db.String(100),nullable=False)
content = db.Column(db.Text)
user = db.Column(db.String(50),db.ForeignKey('user_accounts.username'),nullable=False)
date_created = db.Column(db.DateTime, default=datetime.datetime.utcnow,nullable=False)
completed = db.Column(db.Boolean,default=False,nullable=False)
def __repr__(self):
return f'{self.title} by {self.user} ({self.date_created})'
Error:
sqlalchemy.exc.NoReferencedTableError: Foreign key associated with column 'tasks.author' could not find table 'user' with which to generate a foreign key to target column 'username'
Here I have a problem that when I trying to run db.create_all() in terminal I am getting the above error message. I am a bit confused in the usage of backref for db.relationship as my target is to represent a user could have specific task and a task is owned by that user so may I ask how could I properly organize the relationship between two tables in order to create a table with no error messages?

How do i send a User object (from Python Flask) back to the frontend (Angular) without sending the password hash and salt?

I am using Flask as a Rest API for my WebApp.
In the frontend i use the User object quite often, which is why i need it from the backend to work with the user data.
My concern is, that the user object has an attribute password, which is obviously also sent to the frontend, when i make a request for a user object.
Should i define another class like UserPublic to send to the frontend and just strip out the password or is there a better way to do this with Flask, SQLAlchemy, Marshmallow?
I'm not sure if it's even a problem sending the password hash+salt to the frontend. I mean, i don't need it there, so why send it? Password check for login purposes is done in the backend anyway.
This is my User class:
class User(db.Model):
__tablename__ = 'user'
user_id = db.Column(db.Integer, primary_key=True,autoincrement=True, nullable=False)
public_id = db.Column(db.String, nullable=False)
fname = db.Column(db.String, nullable=False)
lname= db.Column(db.String, nullable=False)
bday = db.Column(db.Date, nullable=False)
street = db.Column(db.String, nullable=False)
zip = db.Column(db.String, nullable=False) #Zip used
city = db.Column(db.String, nullable=False)
country = db.Column(db.String, nullable=False, default='Germany')
password = db.Column(db.String, nullable=False)
admin = db.Column(db.Boolean, default=False)
email = db.Column(db.String, nullable=False)
iban = db.Column(db.String)
bic = db.Column(db.String)
gender = db.Column(db.CHAR, default='m', nullable=False)
created_by = db.Column(db.String)
updated_by = db.Column(db.String)
membership_status_id = db.Column(db.Integer, db.ForeignKey('membership_status.membership_status_id'))
member_since = db.Column(db.Date)
bookings = db.relationship('Booking', backref="User", lazy='select')
Marshmallow Schema:
class UserSchema(ma.SQLAlchemyAutoSchema):
class Meta:
model = User
include_fk = True
This is the endpoint to get a user object:
#app.route('/users/<public_id>', methods=['GET'])
#jwt_required
def get_user(public_id):
logger.info('Getting user with id: '+str(public_id))
current_user = User.query.filter_by(public_id=get_jwt_identity()).first()
if not current_user.admin:
return jsonify({'message' : 'Not privileged for this action'})
user = User.query.filter_by(public_id=public_id).first()
if not user:
return jsonify({'message' : 'No user found with id '+str(public_id)})
user_schema = UserSchema()
return user_schema.jsonify(user), 200
See doc about overriding generated fields.
Here's how to exclude the field from the auto-generated schema:
class UserSchema(ma.SQLAlchemyAutoSchema):
class Meta:
model = User
include_fk = True
exclude = ("password", )
# You may want to only exclude id on dump but keep it on load
# In this case, add it here by calling `auto_field` yourself
password = ma.auto_field(load_only=True)

Handling Duplicate Users In Flask and Flask SQLAlchemy

I want to allow anonymous users to post their comments in a blog without requiring them to login or sign up. One anonymous user can post several comments using the same credentials during subsequent visits. However, I get SQLAlchemy IntegrityError during a second attempt.
I have a simple form, a simple model and a basic route.
comment.py
class CommentForm(FlaskForm):
username = StringField('Username', validators=[DataRequired()])
email = StringField('Email', validators=[DataRequired(), Email()])
comment = TextAreaField('Comment', validators=[DataRequired()])
submit = SubmitField('Post')
models.py
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(64), index=True, unique=True)
email = db.Column(db.String(120), index=True, unique=True)
posts = db.relationship('Post', backref='author', lazy='dynamic')
class Post(db.Model):
id = db.Column(db.Integer, primary_key=True)
body = db.Column(db.String(500))
timestamp = db.Column(db.DateTime, index=True, default=datetime.utcnow)
user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
route.py
#app.route('/personal_blog', methods = ['GET', 'POST'])
def personal_blog():
form = CommentForm()
if form.validate_on_submit():
user = User(username = form.username.data, email = form.email.data)
post = Post(body = form.comment.data, author = user)
db.session.add(user)
db.session.add(post)
db.session.commit()
flash('Your comment is now live!')
return redirect(url_for('personal_blog', _anchor='translate-hover'))
posts = Post.query.order_by(Post.timestamp.desc()).all()
return render_template('personal_blog.html', form = form, posts = posts)
I have tried several suggested solutions and the closet I have come to was to add validation to the form, such as this:
class CommentForm(FlaskForm):
username = StringField('Username', validators=[DataRequired()])
email = StringField('Email', validators=[DataRequired(), Email()])
comment = TextAreaField('Comment', validators=[DataRequired()])
submit = SubmitField('Post')
def __init__(self, original_username, *args, **kwargs):
super(CommentForm, self).__init__(*args, **kwargs)
self.original_username = original_username
def validate_username(self, username):
if username.data != self.original_username:
user = User.query.filter_by(username=self.username.data).first()
if user is not None:
raise ValidationError('Please use a different username.')
This, however, needs the addition of #app.route('/personal_blog/<username>') which essentially does not work for my case. I want to have this anonymous user post subsequent comments without the need of changing either username or email.
Personally, I have tried to add validation within the route (if user.username is not None: flash('Use different credentials!')) to notify the user that the email or username they are trying to use has already been used, and it works, but this is not what I want the app to do. The user can simply use the very same credentials as before. How can this be achieved?
The solution to this is to remove the unique constraint from the User table.
Instead of:
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(64), index=True, unique=True) <----------here
email = db.Column(db.String(120), index=True, unique=True) <----------here
posts = db.relationship('Post', backref='author', lazy='dynamic')
I have this:
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(64), index=True) <----------here
email = db.Column(db.String(120), index=True) <----------here
posts = db.relationship('Post', backref='author', lazy='dynamic')
As soon as I update the database, the changes take effect and I am able to allow a single anonymous user to post more than one comment using the same credentials.

SQLAlchemy not committing changes -- Flask

So what I basically want to do is have a user fill out a form and have a boolean value set to True which tells me their a user. I set it to True when I send the POST request to the database, but when I go look at the column it says "[null]". I don't understand what I'm doing wrong....
class User(db.Model, UserMixin):
id = db.Column(db.Integer, primary_key=True)
first_name = db.Column(db.String(120))
last_name = db.Column(db.String(120))
email = db.Column(db.String(180), unique=True)
password = db.Column(db.String(255))
isUser = db.Column(db.Boolean())
active = db.Column(db.Boolean())
confirmed_at = db.Column(db.DateTime())
roles = db.relationship('Role', secondary=roles_users,backref=db.backref('users', lazy='dynamic'))
#app.route('/post_user', methods=['POST'])
def post_user():
user = User(request.form['first_name'], request.form['last_name'], request.form['email'], request.form['password'])
user.isUser = True
db.session.add(user)
db.session.commit()
return redirect(url_for('login'))

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