<filename>hello.py
from flask import Flask, request, render_template, session, redirect, url_for, flash
from flask_script import Manager, Shell
from flask_bootstrap import Bootstrap
from flask_moment import Moment
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField
from wtforms.validators import Required
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate, MigrateCommand
from flask_mail import Mail, Message
from datetime import datetime
import os
from threading import Thread

basedir = os.path.abspath(os.path.dirname(__file__))

app = Flask(__name__)

# flask-wtf CSRF protection secret key
app.config['SECRET_KEY'] = 'hard to guess string'
# declare database URLS and commit after request
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///'+os.path.join(basedir, 'data.sqlite')
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

app.config['MAIL_SERVER'] = 'smtp.gmail.com'
app.config['MAIL_PORT'] = 587
app.config['MAIL_USE_TLS'] = True
app.config['MAIL_USERNAME'] = os.environ.get('MAIL_USERNAME')
app.config['MAIL_PASSWORD'] = os.environ.get('MAIL_PASSWORD')
app.config['FLASKY_MAIL_SUBJECT_PREFIX'] = '[FLASKY]'
app.config['FLASKY_MAIL_SENDER'] = '<EMAIL>'
app.config['FLASKY_ADMIN'] = os.environ.get('FLASKY_ADMIN')

bootstrap = Bootstrap(app)
manager = Manager(app)
moment = Moment(app)

# WTForms
class NameForm(FlaskForm):
    name = StringField('What is your name?', validators=[Required()])
    submit = SubmitField('Submit')

# SQLAlchemy
db = SQLAlchemy(app)

class Role(db.Model):
    __tablename__ = 'roles'
    id = db.Column(db.Integer, primary_key = True)
    name = db.Column(db.String(64), unique = True)
    users = db.relationship('User', backref = 'role', lazy = 'dynamic')

    def __repr__(self):
        return '<Role %r>' % self.name

class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key = True)
    username = db.Column(db.String(64), unique = True, index = True)
    role_id = db.Column(db.Integer, db.ForeignKey('roles.id'))

    def __repr__(self):
        return '<User %r>' % self.username

def make_shell_context():
    return dict(app = app, db = db, User = User, Role = Role)
manager.add_command('shell', Shell(make_context = make_shell_context))

# db Migration
migrate = Migrate(app, db)
manager.add_command('db', MigrateCommand)

# Mail
mail = Mail(app)

def send_async_email(app, msg):
    with app.app_context():
        mail.send(msg)

def send_email(to, subject, template, **kwargs):
    msg = Message(app.config['FLASKY_MAIL_SUBJECT_PREFIX'] + subject,
            sender = app.config['FLASKY_MAIL_SENDER'],
            recipients = [to]
            )
    msg.body = render_template(template + '.txt', **kwargs)
    msg.html = render_template(template + '.html', **kwargs)
    thr = Thread(target = send_async_email, args = [app, msg])
    thr.start()
    return thr

@app.route('/', methods=['GET', 'POST'])
def index():
    user_agent = request.headers.get('User-Agent') 
    form = NameForm()
    if form.validate_on_submit():
        user = User.query.filter_by(username=form.name.data).first()
        if user is None:
            user = User(username = form.name.data)
            db.session.add(user)
            session['known'] = False
            if app.config['FLASKY_ADMIN']:
                send_email(app.config['FLASKY_ADMIN'], 'New User', 'mail/new_user', user=user)
        else:
            session['known'] = True
        session['name'] = form.name.data
        form.name.data = ''
        return redirect(url_for('index'))
    return render_template('index.html',
            user_agent=user_agent,
            form=form,
            name=session.get('name'),
            known = session.get('known', False),
            )

@app.route('/time')
def time():
    return render_template('time.html', current_time=datetime.utcnow())

@app.route('/user/<name>')
def user(name):
    return render_template('user.html', name=name)

@app.errorhandler(404)
def page_not_found(e):
    return render_template('404.html'), 404

@app.errorhandler(500)
def internal_server_error(e):
    return render_template('500.html'), 500

if __name__ == '__main__':
    manager.run() 

<filename>hello.py
from flask import Flask, request, render_template, session, redirect, url_for, flash
from flask_script import Manager, Shell
from flask_bootstrap import Bootstrap
from flask_moment import Moment
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField
from wtforms.validators import Required
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate, MigrateCommand
from flask_mail import Mail, Message
from datetime import datetime
import os
from threading import Thread

basedir = os.path.abspath(os.path.dirname(__file__))

app = Flask(__name__)

# flask-wtf CSRF protection secret key
app.config['SECRET_KEY'] = 'hard to guess string'
# declare database URLS and commit after request
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///'+os.path.join(basedir, 'data.sqlite')
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

app.config['MAIL_SERVER'] = 'smtp.gmail.com'
app.config['MAIL_PORT'] = 587
app.config['MAIL_USE_TLS'] = True
app.config['MAIL_USERNAME'] = os.environ.get('MAIL_USERNAME')
app.config['MAIL_PASSWORD'] = os.environ.get('MAIL_PASSWORD')
app.config['FLASKY_MAIL_SUBJECT_PREFIX'] = '[FLASKY]'
app.config['FLASKY_MAIL_SENDER'] = '<EMAIL>'
app.config['FLASKY_ADMIN'] = os.environ.get('FLASKY_ADMIN')

bootstrap = Bootstrap(app)
manager = Manager(app)
moment = Moment(app)

# WTForms
class NameForm(FlaskForm):
    name = StringField('What is your name?', validators=[Required()])
    submit = SubmitField('Submit')

# SQLAlchemy
db = SQLAlchemy(app)

class Role(db.Model):
    __tablename__ = 'roles'
    id = db.Column(db.Integer, primary_key = True)
    name = db.Column(db.String(64), unique = True)
    users = db.relationship('User', backref = 'role', lazy = 'dynamic')

    def __repr__(self):
        return '<Role %r>' % self.name

class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key = True)
    username = db.Column(db.String(64), unique = True, index = True)
    role_id = db.Column(db.Integer, db.ForeignKey('roles.id'))

    def __repr__(self):
        return '<User %r>' % self.username

def make_shell_context():
    return dict(app = app, db = db, User = User, Role = Role)
manager.add_command('shell', Shell(make_context = make_shell_context))

# db Migration
migrate = Migrate(app, db)
manager.add_command('db', MigrateCommand)

# Mail
mail = Mail(app)

def send_async_email(app, msg):
    with app.app_context():
        mail.send(msg)

def send_email(to, subject, template, **kwargs):
    msg = Message(app.config['FLASKY_MAIL_SUBJECT_PREFIX'] + subject,
            sender = app.config['FLASKY_MAIL_SENDER'],
            recipients = [to]
            )
    msg.body = render_template(template + '.txt', **kwargs)
    msg.html = render_template(template + '.html', **kwargs)
    thr = Thread(target = send_async_email, args = [app, msg])
    thr.start()
    return thr

@app.route('/', methods=['GET', 'POST'])
def index():
    user_agent = request.headers.get('User-Agent') 
    form = NameForm()
    if form.validate_on_submit():
        user = User.query.filter_by(username=form.name.data).first()
        if user is None:
            user = User(username = form.name.data)
            db.session.add(user)
            session['known'] = False
            if app.config['FLASKY_ADMIN']:
                send_email(app.config['FLASKY_ADMIN'], 'New User', 'mail/new_user', user=user)
        else:
            session['known'] = True
        session['name'] = form.name.data
        form.name.data = ''
        return redirect(url_for('index'))
    return render_template('index.html',
            user_agent=user_agent,
            form=form,
            name=session.get('name'),
            known = session.get('known', False),
            )

@app.route('/time')
def time():
    return render_template('time.html', current_time=datetime.utcnow())

@app.route('/user/<name>')
def user(name):
    return render_template('user.html', name=name)

@app.errorhandler(404)
def page_not_found(e):
    return render_template('404.html'), 404

@app.errorhandler(500)
def internal_server_error(e):
    return render_template('500.html'), 500

if __name__ == '__main__':
    manager.run() 

# flask-wtf CSRF protection secret key # declare database URLS and commit after request # WTForms # SQLAlchemy # db Migration # Mail