QuickStart App

• Intro       • QuickStart App       • Basic App       • MongoDB App      

The QuickStart App allows users to register and login with a username and avoids the need to configure SMTP settings.

Create a development environment

We recommend making use of virtualenv and virtualenvwrapper:

# Create virtual env
mkvirtualenv my_app
workon my_app

# Create working directory
mkdir -p ~dev/my_app           # or  mkdir C:\dev\my_app
cd ~/dev/my_app                # or  cd C:\dev\my_app

Install required Python packages

pip install Flask-User

Create the quickstart_app.py file

  • Open your favorite editor,
  • Copy the example below, and
  • Save it as ~/dev/my_app/quickstart_app.py
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# This file contains an example Flask-User application.
# To keep the example simple, we are applying some unusual techniques:
# - Placing everything in one file
# - Using class-based configuration (instead of file-based configuration)
# - Using string-based templates (instead of file-based templates)

from flask import Flask, render_template_string
from flask_sqlalchemy import SQLAlchemy
from flask_user import login_required, UserManager, UserMixin


# Class-based application configuration
class ConfigClass(object):
    """ Flask application config """

    # Flask settings
    SECRET_KEY = 'This is an INSECURE secret!! DO NOT use this in production!!'

    # Flask-SQLAlchemy settings
    SQLALCHEMY_DATABASE_URI = 'sqlite:///quickstart_app.sqlite'    # File-based SQL database
    SQLALCHEMY_TRACK_MODIFICATIONS = False    # Avoids SQLAlchemy warning

    # Flask-User settings
    USER_APP_NAME = "Flask-User QuickStart App"      # Shown in and email templates and page footers
    USER_ENABLE_EMAIL = False      # Disable email authentication
    USER_ENABLE_USERNAME = True    # Enable username authentication
    USER_REQUIRE_RETYPE_PASSWORD = False    # Simplify register form


def create_app():
    """ Flask application factory """
    
    # Create Flask app load app.config
    app = Flask(__name__)
    app.config.from_object(__name__+'.ConfigClass')

    # Initialize Flask-SQLAlchemy
    db = SQLAlchemy(app)

    # Define the User data-model.
    # NB: Make sure to add flask_user UserMixin !!!
    class User(db.Model, UserMixin):
        __tablename__ = 'users'
        id = db.Column(db.Integer, primary_key=True)
        active = db.Column('is_active', db.Boolean(), nullable=False, server_default='1')

        # User authentication information. The collation='NOCASE' is required
        # to search case insensitively when USER_IFIND_MODE is 'nocase_collation'.
        username = db.Column(db.String(100, collation='NOCASE'), nullable=False, unique=True)
        password = db.Column(db.String(255), nullable=False, server_default='')
        email_confirmed_at = db.Column(db.DateTime())

        # User information
        first_name = db.Column(db.String(100, collation='NOCASE'), nullable=False, server_default='')
        last_name = db.Column(db.String(100, collation='NOCASE'), nullable=False, server_default='')

    # Create all database tables
    db.create_all()

    # Setup Flask-User and specify the User data-model
    user_manager = UserManager(app, db, User)

    # The Home page is accessible to anyone
    @app.route('/')
    def home_page():
        # String-based templates
        return render_template_string("""
            {% extends "flask_user_layout.html" %}
            {% block content %}
                <h2>Home page</h2>
                <p><a href={{ url_for('user.register') }}>Register</a></p>
                <p><a href={{ url_for('user.login') }}>Sign in</a></p>
                <p><a href={{ url_for('home_page') }}>Home page</a> (accessible to anyone)</p>
                <p><a href={{ url_for('member_page') }}>Member page</a> (login required)</p>
                <p><a href={{ url_for('user.logout') }}>Sign out</a></p>
            {% endblock %}
            """)

    # The Members page is only accessible to authenticated users via the @login_required decorator
    @app.route('/members')
    @login_required    # User must be authenticated
    def member_page():
        # String-based templates
        return render_template_string("""
            {% extends "flask_user_layout.html" %}
            {% block content %}
                <h2>Members page</h2>
                <p><a href={{ url_for('user.register') }}>Register</a></p>
                <p><a href={{ url_for('user.login') }}>Sign in</a></p>
                <p><a href={{ url_for('home_page') }}>Home page</a> (accessible to anyone)</p>
                <p><a href={{ url_for('member_page') }}>Member page</a> (login required)</p>
                <p><a href={{ url_for('user.logout') }}>Sign out</a></p>
            {% endblock %}
            """)

    return app


# Start development web server
if __name__=='__main__':
    app = create_app()
    app.run(host='0.0.0.0', port=5000, debug=True)

Highlighted lines shows the few additional Flask-User code lines.

Run the QuickStart App

Run the QuickStart App with the following command:

cd ~/dev/my_app
python quickstart_app.py

And point your browser to http://localhost:5000.

Troubleshooting

If you receive a SQLAlchemy error message, delete the quickstart_app.sqlite file and restart the app. You may be using an old DB schema in that file.

• Intro       • QuickStart App       • Basic App       • MongoDB App