Flask Admin - Automatically create password hash when creating a new user?

Question

Say I have a user model like:

class User(db.Model, UserMixin):
    id = db.Column(db.Integer, primary_key=True)
    first_name = db.Column(db.String(255))
    last_name = db.Column(db.String(255))
    email = db.Column(db.String(255), unique=True)
    password = db.Column(db.String(255))
    registered_on = db.Column(db.DateTime, nullable=True)
    roles = db.relationship('Role', secondary=roles_users,
                            backref=db.backref('users', lazy='dynamic'))

And an admin view:

class UserView(MyModelView):

    form_columns = (
        'roles',
        'first_name',
        'last_name',
        'email',
        'password',
        'registered_on',
    )

    form_args = dict(
                registered_on=dict(default=datetime.now())
            )

When I create a new user how to I automatically generate a password hash with something like bcrypt?

Answer 1

The easiest option I've found is to add an SQLAlchemy attribute event on User.password and hash the password there if changed. This way, anytime a user password is changed from anywhere, it'll be automatically hashed.

from sqlalchemy import event
from werkzeug.security import generate_password_hash


@event.listens_for(User.password, 'set', retval=True)
def hash_user_password(target, value, oldvalue, initiator):
    if value != oldvalue:
        return generate_password_hash(value)
    return value