= Form Processing =

Diva comes with a simple module supporting the processing of HTML forms. A [RequestHandlers request handler] that does some simple form processing typically looks something like this:

{{{
#!python
from diva.forms import Form, TextValidator
from diva.routing import redirect_to
from diva.templating import output, render

class LinkForm(Form):
    username = TextValidator(required=True)
    url = TextValidator(required=True)
    title = TextValidator(required=True)

@output('submit.html')
def submit(request, response):
    form = LinkForm()
    if request.method == 'POST':
        if 'cancel' in request.POST:
            redirect_to('index')
        if form.validate(request.POST):
            # Form is valid, store data int the database
            link = Link(**form.data)
            link.store(app.db)
            redirect_to('info', link.id)
    return render(errors=form.errors)
}}}

This simple example already does a couple of things you may not expect:
 * When the form is redisplayed on `POST` due to validation errors, the form elements will already be populated with the previously entered values.
 * The form submission is protected against Cross-Site Request Forgery (CSRF) attacks, by adding a form token both as a cookie, and as a hidden form input field.

== API Documentation ==

[[PythonDoc(trunk, diva.forms)]]