User Model and Registration form

User model

Create a class User which inherits from Sqlalchemy's Model. We will define all the models(Tables) needed for our project in models.py file in blog package

from blog import db


class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(20), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    image_file = db.Column(db.String(20), nullable=False, default='default.jpg')
    password = db.Column(db.String(60), nullable=False)

inheriting Model allows sqlalchemy to interact with a table against the class User.

Now, we need to create a table in the database that resembles our class User

open python console by entering python in the terminal and enter the following commands:

• from blog import db
• from blog.models import User
• db.create_all()

db.create_all() will create a table named "user(the name will be in lowercase)" in our database.

Note: for db.create_all() to work, you need to import all the class for which you want to create a table

Creating User forms

Now that we have user model, we need to create a form so that user can sign up. Instead of creating form manually, we will use WTForms to make our task easier

WTforms:

• WTForms is a flexible forms validation and rendering library for Python web development.
• It can work with whatever web framework and template engine you choose.
• It supports data validation, CSRF protection, internationalization (I18N)

Install wtform using pip

pip install flask-wtf

Now that we have installed wtform, we will create forms.py in our blog package to add all the forms needed for our project

blog/forms.py

from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, SubmitField
from wtforms.validators import DataRequired, Length, Email, ValidationError
from blog.models import User


class RegistrationForm(FlaskForm):
    username = StringField('Username', validators=[DataRequired(), Length(min=2, max=30)])
    email = StringField('Email', validators=[DataRequired(), Email()])
    password = PasswordField('Password', validators=[DataRequired()])
    confirm_password = PasswordField('Confirm Password', validators=[DataRequired()])
    submit = SubmitField('Sign Up')

Note: We need to install email-validator so that our form can validate email

pip install email-validator

We have our user model and registration form but we don't have any route established for registering users. we will create a new route so that users can registers to our application

we will update our routes.py to include a route for register

blog/routes.py

from blog.forms import RegistrationForm
.
.
.

@app.route("/registration")
def register():
    form = RegistrationForm()
    return render_template('register.html', form=form)

Implementation can be found over this commit