validate message for 0 tacos

from flask import Flask, g, render_template, flash, redirect, url_for, request
from flask_login import LoginManager, login_user, logout_user, login_required, current_user
from flask_bcrypt import check_password_hash
import forms
import models

app = Flask(__name__)
app.secret_key = '234LWKJEr209U)(@r029fjpJ@)euf2fp2ej'

login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = 'login'


@login_manager.user_loader
def user_loader(userid):
    try:
        return models.User.get(models.User.id == userid)
    except models.DoesNotExist:
        return None


@app.before_request
def before_request():
    # connect to the database
    g.db = models.database
    g.db.connect()


@app.after_request
def after_request(response):
    # close the db connection
    g.db.close()
    return response


@app.route('/login', methods=('GET', 'POST'))
def login():
    form = forms.LoginForm()
    if form.validate_on_submit():
        try:
            user = models.User.select().where(
                models.User.email**form.email.data
            ).get()
            if check_password_hash(user.password, form.password.data):
                login_user(user)
                flash("You're now logged in!")
                return redirect(url_for('index'))
            else:
                flash("Email or password is invalid")
        except models.DoesNotExist:
            flash("Email or password is invalid")
    return render_template('login.html', form=form)


@app.route('/logout')
@login_required
def logout():
    logout_user()
    flash('You have been logged out','success')
    return redirect(url_for('index'))


@app.route('/register',methods=['GET','POST'])
def register():
    form = forms.RegisterForm()
    if form.validate_on_submit():
        flash('You are registered!','success')
        models.User.create_user(
            email=form.email.data,
            password=form.password.data
        )
        return redirect(url_for('index'))
    return render_template('register.html', form=form)


@app.route('/taco',methods=['GET','POST'])
@login_required
def taco():
    form = forms.TacoForm()
    if request.method == 'POST':
        models.Taco.create(
            user=current_user._get_current_object(),
            protein=form.protein.data,
            shell=form.shell.data,
            cheese=form.cheese.data,
            extras=form.extras.data
        )
        flash('Taco created!','success')
        return redirect(url_for('index'))
    return render_template('taco.html',form=form)


@app.route('/')
def index():
    tacos = models.Taco.select().limit(15)
    return render_template('index.html', tacos=tacos)


if __name__ == "__main__":
    models.initialize()

from peewee import *
from flask_login import UserMixin
from flask_bcrypt import generate_password_hash

database = SqliteDatabase('taco.db')


class BaseModel(Model):
    class Meta:
        database = database


class User(UserMixin, BaseModel):
    email = CharField(unique=True)
    password = CharField(max_length=20)

    @classmethod
    def create_user(cls, email, password):
        try:
            cls.create(
                email=email,
                password=generate_password_hash(password)
            )
        except IntegrityError:
            raise ValueError("User already exists")


class Taco(BaseModel):
    user = ForeignKeyField(User)
    protein = CharField()
    shell = CharField()
    cheese = BooleanField()
    extras = CharField()

    @classmethod
    def create_taco(cls, user, protein, shell, cheese, extras):
        cls.create(
            user=user,
            protein=protein,
            shell=shell,
            cheese=cheese,
            extras=extras
        )


def initialize():
    database.connect()
    database.create_tables([User,Taco],safe=True)
    database.close()

from flask_wtf import Form
from wtforms import StringField, PasswordField, BooleanField, TextField
from wtforms.validators import DataRequired, Regexp, ValidationError, Length, EqualTo, Email

from models import User


def name_exists(form, field):
    if User.select().where(User.username == field.data).exists():
        raise ValidationError('User with that name already exists')


def email_exists(form, field):
    if User.select().where(User.email == field.data).exists():
        raise ValidationError('User with that email already exists')


class RegisterForm(Form):
    email = StringField(
        'email',
        validators=[
            DataRequired(),
            Email(),
            email_exists
        ]
    )

    password = PasswordField(
        'password',
        validators=[
            DataRequired(),
            Length(min=2),
            EqualTo('password2', message='Passwords must match')
        ]
    )

    password2 = PasswordField(
        'Confirm password',
        validators=[DataRequired()]
    )


class LoginForm(Form):
    email = StringField(
        'email',
        validators=[
            DataRequired(),
            Email()
        ]
    )

    password = PasswordField(
        'password',
        validators=[
            DataRequired()
        ]
    )


class TacoForm(Form):
    protein = StringField(
        'protein',
        validators=[DataRequired()]
    )
    shell = StringField(
        'shell',
        validators=[DataRequired()]
    )
    cheese = BooleanField(
        'cheese',
        validators=[DataRequired()]
    )
    extras = StringField(
        'extras',
        validators=[DataRequired(),Length(100)]
    )