使用带有参数的 url_for 进行 Flask 重定向

Question

I'm trying redirect the function to herself, but changing the value of a parameter.

This is my code:

@app.route('/', methods=["GET", "POST"])
def index(save=False):
    form = FormFields()
    if form.validate_on_submit:
        csv = Csv(form)
        csv.savecsv()
        return redirect(url_for('index', save=True))
    else:
        print(form.errors)
    return render_template('form.html', form=form, save=save)

I would like that when redirecting, the save variable would be True, but it is always False.

In the form code I have this:

{% if save %}
    <script type="text/javascript"> alert("Saved!");</script>
{% endif %}

Answer 1

Use the default values in route:

    @app.route('/', methods=["GET", "POST"], defaults={'save': False})
    @app.route('/<save>', methods=["GET", "POST"])
    def index(save):
        form = FormFields()
        if form.validate_on_submit:
            csv = Csv(form)
            csv.savecsv()
            return redirect(url_for('index', save=True))
        else:
            print(form.errors)
        return render_template('form.html', form=form, save=save)

Answer 2

I found an alternative solution

I changed it:

return redirect(url_for('index', save=True))

for this one

return render_template('form.html', form=form, save=True)

It will make a new render

and I added this in the form.html code

$(document).ready(function() {
    $('input').val("");
});

this solves my problem, and the reason is that I have a confirmation message (when save is True) and the fields are cleared

but if someone really needs a return redirect url_for can use Suman Niroula's solution without problems