Question

I am building a Form object using pyramid_simpleform. I would like to have one method that builds the form object and once submitted it attempts to validate it.

If the input valid, I’ll redirect the user to a confirmation page. Otherwise, I’ll render an error page. I am using form.validate() to see if the input data fits the schema.

If the form has not been submitted, I’d like to display the form using a render_to_response. How do I detect whether the form has been submitted?

Answer 1

Quick answer

Like Furbeenator answered:

if request.method == "POST":

Long answer

You should split your logic in two different view functions.

Also, you should return a form renderer to be used by your template instead of rendering the form straight in the view function. For example:

./forms.py:

from formencode import Schema, validators

class RegistrationForm(Schema):
    email = validators.Email(not_empty=True, strip=True)
    password = validators.UnicodeString(not_empty=True)
    password_confirm = validators.UnicodeString()
    chained_validators = [validators.FieldsMatch(
                    'password', 'password_confirm',
                    messages=dict(invalidNoMatch=u'Password does not match'))]

./views/accounts.py:

from pyramid_simpleform import Form
from pyramid_simpleform.renderers import FormRenderer
from pyramid.view import view_config
from pyramid.httpexceptions import HTTPFound
from pyramid.url import route_url
from ..forms import RegistrationForm
from ..models import DBSession, User

@view_config(route_name='accounts_register', renderer='/accounts/register.mako',
            request_method='GET')
def register(request):
    """Shows the empty form."""
    form = Form(request, schema=RegistrationForm)
    return {'renderer': FormRenderer(form)}

@view_config(route_name='accounts_register', renderer='/accounts/register.mako',
            request_method='POST')
def register_post(request):
    """Receives the posted form."""
    form = Form(request, schema=RegistrationForm)
    if form.validate():
        user = User(form.data['email'], form.data['password'])
        DBSession.add(user)
        return HTTPFound(route_url('profile', request))
    return {'renderer': FormRenderer(form)}

./templates/accounts/register.mako:

<form action="" method="post">
  <div class="${' error' if renderer.is_error('email') else ''}">
    <label for="email">Email</label>
    ${renderer.text('email', type='email', placeholder='Email')}
    % if renderer.is_error('email'):
      <span class="errors">${', '.join(renderer.errors_for('email'))}</span>
    % endif
  </div>    
  <!-- ... --->
</form>