Flask wtform errors rather than field errors

Question

I understand how to validate each field and show each error if needed. But how do I show a form error.

What I mean is that the user may enter valid info, but the form might be wrong as a whole.

Example: Form with username and password. Each would have a validator. How can I display an error if the login failed (account doesn't exist or incorrect password)?

I tried raising a ValidationError... but that just raises an error as normal.

def login():
    form = LoginForm(request.form)
    if form.validate_on_submit():
        username = form.username.data
        password = form.password.data

        if login(username, password):
            return redirect(url_for('dashboard'))
        else:
            raise ValidationError('Invalid login')

    return render_template('login.html', form=form)

hukaixuan · Accepted Answer · 2017-03-20 02:22:15Z

2

change your raise ValidationError('Invalid login') to flash('Invalid login')
and remember to from flask import flash
then add a field to your 'login.html' to show this message

{% for message in get_flashed_messages() %}
<div class="alert alert-warning">
    <button type="button" class="close" data-dismiss="alert">&times;</button>
    {{ message }}
</div>
{% endfor %}

answered Mar 20, 2017 at 2:22

hukaixuan

3762 silver badges10 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

ovg Over a year ago

Oh I had forgotten about that. Is that what flash is normally for? It's there any way to send the error through wtforms?

hukaixuan Over a year ago

I usually use this way and you can add the field to your base template,so you can use flash everywhere. I don't know how to do this with wtforms.

Collectives™ on Stack Overflow

Flask wtform errors rather than field errors

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related