Flask validate_on_submit always False

Question

I know that there are similar problems which have been answered. The csrf_enabled is not an issue now if the Form inheriting FlaskForm, and the template has the form.hidden_tag().

I have the following flask app.

## Filenname: app.py

from flask import Flask, render_template, redirect, url_for, flash, request
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField, SelectField
from wtforms.validators import DataRequired

app = Flask(__name__)

app.config["SECRET_KEY"] = "secret"



class DataForm(FlaskForm):
    name = StringField("Name", validators=[DataRequired()])
    gender = SelectField("Gender", validators=None, choices=[(1, 'M'), (2, "F")])
    submit = SubmitField("Submit", validators=None)



@app.route('/index', methods=["GET", "POST"])
def index():
    form = DataForm(request.form)
    print(form.validate_on_submit())
    if form.validate_on_submit():
        print(form.validate())
        print(form.name)
        flash("THIS IS FLASH")
        title="hello"
        return redirect(url_for('output'))
    return render_template('index.html', form=form)



@app.route('/output', methods=["GET", "POST"])
def output():
    title = "hello"
    form = DataForm()
    print(form.validate())
    return render_template('output.html', title=title)


app.run(debug=False)

The following is index.html template:

<html>
    <body>
        {% with messages = get_flashed_messages() %}
        {{ messages }}
        {% endwith %}



        <form action="" method="GET">
            {{ form.hidden_tag() }}
            {{ form.name.label }}
            {{ form.name() }}
            {% for error in form.name.errors %}
            <span style="color: red;">[{{ error }}]</span>
            {% endfor %}

            <hr>

            {{ form.gender.label }}
            {{ form.gender() }}

            {{ form.submit() }}
        </form>
    </body>
</html>

After clicking the submit button the execution never goes in the if form.validate_on_submit() block in the index function.

I also removed all the validators, the code inside validate_on_submit block is still unreachable. Printing form.validate_on_submit() is always false.

Asked By: Shishir Pandey

||

Source

Answer 1

So there are multiple problems.

Change your choices to strings:
```
choices=[('1', 'M'), ('2', "F")]
```
Change your form method to POST, because validate_on_submit() requires it:
```
<form action="" method="POST">
```
Additionally, to debug other possible errors (like CSRF), add this to your template:
```
{% if form.errors %}
{{ form.errors }}
{% endif %}
```

That fixed your code for me.

Answered By: Andriy Makukha

Answer 2

just make form without

2.form = FlaskForm(meta={‘csrf’: False})

Answered By: Bekzod Qodirov

Answer 3

Just print csrf_token with jinja and it will return True.

<form method="POST" action="#">
   {{ form.csrf_token }}
</form>

Answered By: Orbytoo

Flask validate_on_submit always False

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