Gremoire

Implementing Authentication in Flask ​

Flask is a popular Python web framework that is known for its simplicity and flexibility. Flask does not provide built-in support for authentication like Django, but it provides several extensions that you can use to implement authentication in your Flask web application.

Flask-Login ​

Flask-Login is a popular extension for implementing user authentication in Flask. It provides a simple way to manage user sessions and includes features like user authentication, user sessions, and user permissions.

python
from flask_login import LoginManager, UserMixin, login_required

app = Flask(name)
app.config['SECRET_KEY'] = 'your-secret-key'

login_manager = LoginManager()
login_manager.init_app(app)

class User(UserMixin):
pass

@login_manager.user_loader
def user_loader(user_id):
user = User()
user.id = user_id
return user

@app.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'POST':
email = request.form['email']
password = request.form['password']
user = authenticate(email, password)
if user:
login_user(user)
return redirect(url_for('dashboard'))
else:
flash('Invalid email or password')
return render_template('login.html')

@app.route('/dashboard')
@login_required
def dashboard():
return render_template('dashboard.html')

Flask-JWT ​

Flask-JWT is another popular extension for implementing authentication in Flask. It provides JSON Web Token (JWT) authentication, which is a stateless authentication mechanism that does not require storing user sessions on the server.

python

from flask_jwt_extended import JWTManager, jwt_required, create_access_token

app = Flask(name)
app.config['JWT_SECRET_KEY'] = 'your-secret-key'

jwt = JWTManager(app)

@app.route('/login', methods=['POST'])
def login():
email = request.json.get('email', None)
password = request.json.get('password', None)
user = authenticate(email, password)
if user:
access_token = create_access_token(identity=user.id)
return jsonify(access_token=access_token)
else:
return jsonify({'message': 'Invalid email or password'}), 401

@app.route('/dashboard')
@jwt_required
def dashboard():
return jsonify({'message': 'Welcome to your dashboard'})

Conclusion ​

Flask provides several extensions that you can use to implement authentication in your Flask web application. Flask-Login provides user sessions and user permissions, while Flask-JWT provides JSON Web Token authentication. With these tools, you can create secure web applications with Flask.