Question

I’m trying to implement a user registration page in Django. Seems like a simple task, but I’m getting an error I just don’t understand. Here’s my view:

def registration_page(request):
  if request.method == 'POST':
    form = RegistrationForm(request.POST)
    if form.is_valid():
      user = User.objects.create_user(
        username = form.cleaned_data['username'],
        password = form.cleaned_data['password1'],
        email = form.cleaned_data['email1']
      )
      return HttpResponseRedirect('/register/success/')
  else:
    form = RegistrationForm()

  variables = RequestContext(request, {
    'form': form
  })
  return render_to_response('registration/registration_page.html', variables)

And here’s my registration form:

class RegistrationForm(forms.Form):
  username = forms.CharField(label = u'Username', max_length = 30, error_messages={'required': 'A username is required.'})
  email1 = forms.EmailField(label = u'Email Address', error_messages={'required': 'An email address is required.'})
  email2 = forms.EmailField(label = u'Email Address confirmation', error_messages={'required': 'A confirmed email address is required.'})
  password1 = forms.CharField(label = u'Password', widget = forms.PasswordInput(), error_messages={'required': 'A password is required.'})
  password2 = forms.CharField(label = u'Password confirmation', widget = forms.PasswordInput(), error_messages={'required': 'A confirmed password is required.'})

  def clean_password2(self):
    if 'password1' in self.cleaned_data:
      password1 = self.cleaned_data['password1']
      password2 = self.cleaned_data['password2']
      if password1 == password2:
        return password2
    raise forms.ValidationError('Passwords must be identical. Remember, passwords are case-sensitive.')

  def clean_email2(self):
    if 'email1' in self.cleaned_data:
      email1 = self.cleaned_data['email1']
      email2 = self.cleaned_data['email2']
      if email1 == email2:
        if User.objects.get(email = email1):
          raise forms.ValidationError("The email address '%s' is already associated with an account. This typically means you created an account in the past. Please use it." % email1)
        else:
          return email2
    raise forms.ValidationError('Email addresses must be identical.')


  def clean_username(self):
    if 'username' in self.cleaned_data:
      username = self.cleaned_data['username']
      if not re.search(r'^\w+$', username):
        raise forms.ValidationError('Username can only contain letters, numbers, and the underscore characters.')
      try:
        User.objects.get(username = username)
      except User.DoesNotExist:
        return username
    raise forms.ValidationError("Username '%s' is already taken." % username)

The problem pops up in the form.is_valid() and clean_username(). If I add a user that does or does not exist (it doesn’t matter if the user exists or not, behavior is the same) and populate the form with data I know is valid, the code should simply return username from clean_username() and form.is_valid() should be True. Instead, I get an error page that looks like this:

DoesNotExist at /register/
User matching query does not exist.
Request Method: POST
Request URL:    http://127.0.0.1:8000/register/
Django Version: 1.4.1
Exception Type: DoesNotExist
Exception Value:    
User matching query does not exist.
Exception Location: /opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py in get, line 366
Python Executable:  /opt/local/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python
Python Version: 2.7.2
Python Path:    
['/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/distribute-0.6.28-py2.7.egg',
 '/Library/Python/2.7/site-packages/bpython-0.10.1-py2.7.egg',
 '/Library/Python/2.7/site-packages/Pygments-1.5-py2.7.egg',
 '/Library/Python/2.7/site-packages/django_registration-0.8-py2.7.egg',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python27.zip',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/PIL',
 '/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/setuptools-0.6c11-py2.7.egg-info',
 '/Library/Python/2.7/site-packages']
Server time:    Sun, 28 Oct 2012 00:51:58 -0400

It’s got to be something small I’m missing, but I can’t see it.

Answer 1

In your code

def clean_email2(self):
    ...
        # here
        if User.objects.get(email = email1):
          raise forms.ValidationError("The email address '%s' is already associated with an account. This typically means you created an account in the past. Please use it." % email1)
    ...

The get() could cause DoesNotExist but is not captured. Is that the issue?

Also, please provide full traceback of the line making the issue.

Furthermore, according to the doc, its better to put the logic of validating passwords & emails to the clean() method.