Database Table
CREATE TABLE user (
id INTEGER PRIMARY KEY AUTOINCREMENT,
username VARCHAR (64),
email VARCHAR (120),
password_hash VARCHAR (128)
);
install module flask_login module
ModuleNotFoundError: No module named 'flask_login' = (venv) C:\flaskmyproject>pip install flask_login
install flask_sqlalchemy module
ModuleNotFoundError: No module named 'flask_sqlalchemy' = (venv) C:\flaskmyproject>pip install Flask-SQLAlchemy
install flask_wtf module
pip install Flask-WTF
app.py
#app.py
from flask import Flask, render_template, flash, redirect, url_for
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user, current_user
#ModuleNotFoundError: No module named 'flask_sqlalchemy' = (venv) C:\flaskmyproject>pip install Flask-SQLAlchemy
#ModuleNotFoundError: No module named 'flask_login' = (venv) C:\flaskmyproject>pip install flask_login
from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, BooleanField, SubmitField
from wtforms.validators import DataRequired
from werkzeug.security import generate_password_hash, check_password_hash
#import sqlite3
app = Flask(__name__)
#conn = sqlite3.connect('flask_login.db')
#print("Opened database successfully");
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///flask_login.db'
app.config['SECRET_KEY'] = 'cairocoders-ednalan'
db = SQLAlchemy(app)
login_manager = LoginManager()
login_manager.init_app(app)
class LoginForm(FlaskForm):
username = StringField('Username', validators=[DataRequired()])
password = PasswordField('Password', validators=[DataRequired()])
remember_me = BooleanField('Remember Me')
submit = SubmitField('Sign In')
class User(UserMixin, 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)
password_hash = db.Column(db.String(128))
def __repr__(self):
return ''.format(self.username)
def set_password(self, password):
self.password_hash = generate_password_hash(password)
def check_password(self, password):
return check_password_hash(self.password_hash, password)
@login_manager.user_loader
def load_user(user_id):
return User.query.get(int(user_id))
@login_manager.unauthorized_handler
def unauthorized_callback():
return redirect('/login')
@app.route('/')
def index():
hash = generate_password_hash('cairocoders')
check_hash = check_password_hash(hash, 'cairocoders')
return render_template('index.html', hash=hash, check_hash=check_hash)
@app.route('/login', methods=['GET', 'POST'])
def login():
if current_user.is_authenticated:
return redirect(url_for('index'))
form = LoginForm()
if form.validate_on_submit():
user = User.query.filter_by(username=form.username.data).first()
if user is None or not user.check_password(form.password.data):
flash('Invalid username or password')
return redirect(url_for('login'))
login_user(user, remember=form.remember_me.data)
return redirect(url_for('index'))
return render_template('login.html', title='Sign In', form=form)
@app.route('/home')
@login_required
def home():
return 'The current user is ' + current_user.username
@app.route('/profile')
@login_required
def profile():
return render_template('profile.html')
@app.route('/logout')
@login_required
def logout():
logout_user()
return 'You are now logged out!'
if __name__ == '__main__':
app.run(debug=True)
templates/login.html
//templates/login.html
<html lang="en">
<head>
<title>Login</title>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
</head>
<body>
<div id="login">
<h3 class="text-center text-white pt-5">Login Flask using flask_login module with flask_wtf and remember me and check_password_hash</h3>
<div class="container">
<div id="login-row" class="row justify-content-center align-items-center">
<div id="login-column" class="col-md-6">
<div id="login-box" class="col-md-12">
<form id="login-form" class="form" action="" method="post" novalidate>
{{ form.hidden_tag() }}
<div class="form-group">
{{ form.username.label }}<br>
{{ form.username(size=32, class_="form-control") }}
{% for error in form.username.errors %}
<span style="color: red;">[{{ error }}]</span>
{% endfor %}
</div>
<div class="form-group">
{{ form.password.label }}<br>
{{ form.password(size=32, class_="form-control") }}
{% for error in form.password.errors %}
<span style="color: red;">[{{ error }}]</span>
{% endfor %}
</div>
<p>{{ form.remember_me() }} {{ form.remember_me.label }}</p>
<p>{{ form.submit(class_="btn btn-success") }}</p>
</form>
</div>
</div>
</div>
</div>
</div>
<style>
body {
margin: 0;
padding: 0;
background-color: #17a2b8;
}
#login .container #login-row #login-column #login-box {
margin-top: 120px;
max-width: 600px;
height: 350px;
border: 1px solid #9C9C9C;
background-color: #EAEAEA;
}
#login .container #login-row #login-column #login-box #login-form {
padding: 20px;
}
#login .container #login-row #login-column #login-box #login-form #register-link {
margin-top: -85px;
}
</style>
</body>
</html>
templates/index.html
//templates/index.html
<html lang="en">
<head>
<meta charset="utf-8">
<title>Index</title>
</head>
<body>
<div>
<a href="{{ url_for('index') }}">Home</a>
{% if current_user.is_anonymous %}
<a href="{{ url_for('login') }}">Login</a>
{% else %}
<a href="{{ url_for('logout') }}">Logout</a>
{% endif %}
</div>
<h1>Hi, {{ current_user.username }}!</h1>
<p>password hash, {{ hash }}</p>
<p>check password hash, {{ check_hash }}</p>
</body>
</html>
templates/profile.html
//templates/profile.html
<html lang="en">
<head>
<meta charset="utf-8">
<title>profile</title>
</head>
<body>
<div>
<a href="{{ url_for('index') }}">Home</a>
{% if current_user.is_anonymous %}
<a href="{{ url_for('login') }}">Login</a>
{% else %}
<a href="{{ url_for('logout') }}">Logout</a>
{% endif %}
</div>
<h1>Hi, {{ current_user.username }}!</h1>
</body>
</html>
