Problem with Flask wtforms validation errors - flask

Question

Flask wtforms doesn't show validation errors (eg. when password dont match).
forms.py
from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, BooleanField, SubmitField
from wtforms.validators import DataRequired, Length, Email, ValidationError, EqualTo, Regexp
class RegistrationForm(FlaskForm):
username = StringField('Username', validators=[DataRequired(), Length(min=5, message='Name length must be between %(min)d')]), Regexp("^[A-Za-z][A-Za-z0-9_.]*$", 0, "Username must have")
password = PasswordField('Password', validators=[DataRequired(), Length(min=8, message='Password should be at least %(min)d characters long')])
confirm_password = PasswordField('Confirm Password', validators=[DataRequired(message='*Required'), EqualTo('password', message='Both password fields must be equal!')])
email = StringField('Email', validators=[DataRequired(), Email()])
register = SubmitField('Register')
respective snippet from registration.html
<div class = "input-group mb-3">
{{form.confirm_password.label(class="form control table")}}
{{form.confirm_password(class="form-control form-control-lg", id="floatingPassword", placeholder="Confirm Password")}}
</div>
{% for error in form.password.errors %}
<div class="alert alert-danger input-group" role="alert">
<span style="color: red;">{{ error }}</span>
</div>
{% endfor %}
and snippet from route function views.py
#custodian_view.route('/register', methods=['GET', 'POST'])
def register():
form = RegistrationForm(request.form)
if request.method == 'POST':
if form.validate_on_submit:
user = Account(email=form.email.data, username=form.username.data, password=form.password.data)
db.session.add(user)
db.session.commit()
Please, advice how can I fix this problem

Answer 1

If the passwords don't match, the error message will be sent via form.confirm_password.errors.
So you have to change this line:
{% for error in form.password.errors %}
into this:
{% for error in form.confirm_password.errors %}