[PYTHON] Creating a web application using Flask ④

Creating a new registration function

This time, we will add a new user registration function.

User model definition

Create a model for User, just as you created a Review model last time.

python:./cafesite/models/users.py

from cafe_site import db
from datetime import datetime
import bcrypt

class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(50))
    password = db.Column(db.String(50))
    salt = db.Column(db.String(50))
    created_at = db.Column(db.DateTime)

    def __init__(self, username=None, password=None):
        self.username = username
        self.salt = bcrypt.gensalt().decode()
        self.password = bcrypt.hashpw(password.encode(), self.salt.encode()).decode()
        self.created_at = datetime.utcnow()

    def __repr__(self):
        return '<Entry id:{} username:{}>'.format(self.id, self.username)

Password protection

Since it is not good for security to save the password as it is in the database, the password is encrypted and saved in the database. bcrypt In ** users.py **, generate salt with self.salt = bcrypt.gensalt (). Decode (), Security is enhanced by combining the password hashed with self.password = bcrypt.hashpw (password.encode (), self.salt.encode ()). Decode () with the generated salt. I will.

Review model changes

Add a process to models / reviews.py to determine which user wrote the article.

python:./cafesite/models/reviews.py

from cafe_site import db
from datetime import datetime

class Review(db.Model):
    from cafe_site.models.users import User
    __tablename__ = 'Reviews'
    id = db.Column(db.Integer, primary_key=True)
    star = db.Column(db.Integer)
    title = db.Column(db.String(50), unique=True)
    text = db.Column(db.Text)
    user_id = db.Column(db.Integer, db.ForeignKey('users.id'))
    user = db.relationship('User', foreign_keys=user_id)
    created_at = db.Column(db.DateTime)

    def __init__(self, star=None, title=None, text=None, user_id=None):
        self.star = star
        self.title = title
        self.text = text
        self.user_id = user_id
        self.created_at = datetime.utcnow()

    def __repr__(self):
        return '<Review id:{} star:{} title:{} text:{} user_id:{}>'.format(self.id, self.star, self.title, self.text, self.user_id)

Receive the id attribute generated by the User model as a foreign key with ʻuser_id = db.Column (db.Integer, db.ForeignKey ('users.id'))and ʻuser = db.relationship ('User', foreign_keys) = user_id)is processed so that the Review model can be operated using a foreign key.

Added a new post link to the navigation bar

Edit theme.html and add a "Sign up" link for new registration in the navigation bar.

html:./cafe_site/templates/theme.html

<ul class="main-nav">
    {% if not session.logged_in %}
     <li><a href="{{ url_for('user.new_user') }}">Signup</a></li>
    {% else %}

    {% endif %}
</ul>

• Create users.py to return the new registration form when accessing the new registration link, and add new_review.

python:./cafesite/views/users.py

@user.route('/users/new', methods=['GET'])
def new_user():
    return render_template('users/new.html', id='user')

Creating a new registration form

html:./cafe_site/templates/users/new.html

{% extends "theme.html" %}
{% block title %}Coffee House{% endblock %}
{% block head %}
  {{ super() }}
{% endblock %}
{% block content %}
<div class="wrapper">
    <h2 class="page-title">Signup</h2>
</div>
<div class="login-content wrapper">
  <form action="{{ url_for('user.add_user') }}" method=post>
    <div>
      <label for="name">User name</label>
      <input placeholder="username" type="text" name=username>
    </div>
    <div>
      <label for="Password">password</label>
      <input placeholder="password" type="password" name=password>
    </div>
      <input type="submit" class="button" value="sign up">
  </form>
</div>
{% endblock %}
{% block footer %}
  <footer>
      <div class="wrapper">
          <p><small>&copy; Coffee House</small></p>
      </div>
  </footer>
{% endblock %}

Saving user data

This completes the creation of the new registration form. Next, create a function to save the registered user data in the database using the model instance created earlier.

Creating add_user

In users / new.html, the post destination of the form is ʻAction =" {{url_for ('user.add_user')}} "`. Create ** user.add_user ** and add a process to receive the posted content and save it in the database. Add ** add_user ** to views / users.py.

python:./cafesite/views/users.py

@user.route('/users', methods=['POST'])
def add_user():
    user = User(
            username=request.form['username'],
            password=request.form['password']
            )
    db.session.add(user)
    db.session.commit()
    flash('New user registration is complete. Please login.')
    return redirect(url_for('loging.login'))

Use the User model to create a model instance for the username and password sent to you and store it in the database. Now let's take a look at the big picture of views / users.py.

python:./cafesite/views/users.py

from flask import request, redirect, url_for, render_template, flash, session
from cafe_site import app
from cafe_site import db
from cafe_site.models.users import User
from cafe_site.views.loging import login_required
from flask import Blueprint


user = Blueprint('user', __name__)


@user.route('/users', methods=['POST'])
def add_user():
    user = User(
            username=request.form['username'],
            password=request.form['password']
            )
    db.session.add(user)
    db.session.commit()
    flash('New user registration is complete. Please login.')
    return redirect(url_for('loging.login'))


@user.route('/users/new', methods=['GET'])
def new_user():
    return render_template('users/new.html', id='user')

Changes to views / logging.py

python:./cafesite/views/loging.py

from flask import request, redirect, url_for, render_template, flash, session
from cafe_site import app
from functools import wraps
from cafe_site.models.users import User
import bcrypt
from flask import Blueprint

loging = Blueprint('loging', __name__)

def login_required(loging):
    @wraps(loging)
    def inner(*args, **kwargs):
        if not session.get('logged_in'):
            return redirect(url_for('loging.login'))
        return loging(*args, **kwargs)
    return inner


@loging.route('/login', methods=['GET', 'POST'])
def login():
    error = None
    if request.method == 'POST':
        try:
            user = User.query.filter_by(username=request.form['username']).first()
        except:
            flash('The user name is different')
            return render_template('login.html')
        if request.form['username'] != user.username:
            flash('The user name is different')
        elif bcrypt.hashpw(request.form['password'].encode(), user.salt.encode()).decode() != user.password:
            flash('Password is different')
        else:
            session['logged_in'] = True
            session['user_id'] = user.id
            flash('You are now logged')
            return redirect(url_for('review.show_reviews'))
    return render_template('login.html', id="login")

@loging.route('/logout')
def logout():
    session.pop('logged_in', None)
    flash('logged out')
    return redirect(url_for('review.show_reviews'))

@loging.app_errorhandler(404)
def non_existant_route(error):
    return redirect(url_for('loging.login'))

Reprocessed so that you can log in with the user data sent from the User model.

Changes to cafe_site / __ init__.py

Finally, make changes to cafe_site / __ init__.py.

python:./cafe_site/__init__.py

from cafe_site.views.users import user
app.register_blueprint(user)

The web application is now complete.

Next time, I will explain how to launch the web application created this time on the cloud using heroku.