project
   | --- flapp.py
   | --- config.py
   | --- .flaskenv
   | --- app/
          | --- __init__.py
          | --- routes.py
          | --- models.py
          | --- forms.py
          | --- templates/
                  | --- base.html
                  | --- home.html
                  | --- register.html
                  | --- login.html
          | --- static/

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
from flask_login import LoginManager
from config import Config

app = Flask(__name__)
app.config.from_object(Config)

db = SQLAlchemy(app)
migrate = Migrate(app, db)
login = LoginManager(app)
login.login_view = 'login'

from app import routes, models

# flapp.py

from app import app

# routes.py

from app import app

@app.route('/')
@app.route('/home')
def home:
    return 'home'

# .flaskenv

FLASK_APP=school.py
FLASK_ENV=development
FLASK_DEBUG=True

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


class Config(object):
    SECRET_KEY = os.environ.get('SECRET_KEY') or 'difficult-to-guess'
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL') or \
        'sqlite:///' + os.path.join(basedir, 'app.db')
    SQLALCHEMY_TRACK_MODIFICATIONS = False

# models.py

from app import db, login
from werkzeug.security import generate_password_hash, check_password_hash
from flask_login import UserMixin


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.user_loader
def load_user(id):
    return User.query.get(int(id))

# create a migration directory
(venv)$ flask db init 

# Create a migration script
(venv)$ flask db migrate -m 'user table'

# Apply the changes
(venv)$ flask db upgrade

# register.html

{% extends "base.html" %}

{% block content %}
    
Register
    

        {{ form.hidden_tag() }}
        

            {{ form.username.label }}

            {{ form.username(size=32) }}

            {% for error in form.username.errors %}
            [{{ error }}]
            {% endfor %}
        
        

            {{ form.email.label }}

            {{ form.email(size=32) }}

            {% for error in form.email.errors %}
            [{{ error }}]
            {% endfor %}
        
        

            {{ form.password.label }}

            {{ form.password(size=32) }}

            {% for error in form.password.errors %}
            [{{ error }}]
            {% endfor %}
        
        

            {{ form.password2.label }}

            {{ form.password2(size=32) }}

            {% for error in form.password2.errors %}
            [{{ error }}]
            {% endfor %}
        
        
{{ form.submit() }}
    
{% endblock %}

# login.html

{% extends "base.html" %}

{% block content %}
    
Sign In
    

        {{ form.hidden_tag() }}
        

            {{ form.username.label }}

            {{ form.username(size=32) }}

            {% for error in form.username.errors %}
            [{{ error }}]
            {% endfor %}
        
        

            {{ form.password.label }}

            {{ form.password(size=32) }}

            {% for error in form.password.errors %}
            [{{ error }}]
            {% endfor %}
        
        
{{ form.remember_me() }} {{ form.remember_me.label }}
        
{{ form.submit() }}
    
    
New here? Register now!
{% endblock %}

# base.html


    
        {% if title %}
        
        {% else %}
        
        {% endif %}
    
    
        

            SO Demo:
            Home
            {% if current_user.is_anonymous %}
            Login
            {% else %}
            Logout
            {% endif %}
        
        

        {% with messages = get_flashed_messages() %}
        {% if messages %}
        

            {% for message in messages %}
            
{{ message }}
            {% endfor %}
        
        {% endif %}
        {% endwith %}
        {% block content %}{% endblock %}
    

# home.html

{% extends "base.html" %}

{% block content %}
    

        Hi {{ current_user.username }},


        These are your details:
    
    

        Name: {{ current_user.username }}

        Email: {{ current_user.email }}

        Hashed Password: {{ current_user.password_hash }}
    
{% endblock %}

from flask import render_template, flash, redirect, url_for, request
from app import app, db
from app.forms import LoginForm, RegistrationForm
from flask_login import current_user, login_user, logout_user
from app.models import User
from flask_login import login_required
from werkzeug.urls import url_parse


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


@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)
        next_page = request.args.get('next')
        if not next_page or url_parse(next_page).netloc != '':
            next_page = url_for('home')
        return redirect(next_page)
    return render_template('login.html', title='Sign In', form=form)


@app.route('/logout')
def logout():
    logout_user()
    return redirect(url_for('home'))


@app.route('/register', methods=['GET', 'POST'])
def register():
    if current_user.is_authenticated:
        return redirect(url_for('home'))
    form = RegistrationForm()
    if form.validate_on_submit():
        user = User(username=form.username.data, email=form.email.data)
        user.set_password(form.password.data)
        db.session.add(user)
        db.session.commit()
        flash('Congratulations, you are now a registered user!')
        return redirect(url_for('login'))
    return render_template('register.html', title='Register', form=form)