--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/polls/forms.py	Sat May 05 17:10:48 2012 -0500
@@ -0,0 +1,28 @@
+"""Forms for the Polls application."""
+
+from django import forms
+from django.db.models import F
+
+from polls.models import Choice
+
+
+class VoteForm(forms.Form):
+    """Form for voting in a poll."""
+    choices = forms.ModelChoiceField(label='', empty_label=None,
+            queryset=Choice.objects.none(), widget=forms.RadioSelect)
+
+    def __init__(self, poll, *args, **kwargs):
+        self.user = kwargs.pop('user', None)
+        self.user_choice = kwargs.pop('user_choice', None)
+        super(VoteForm, self).__init__(*args, **kwargs)
+        self.fields['choices'].queryset = poll.choice_set.all()
+
+    def clean(self):
+        if self.user_choice:
+            raise forms.ValidationError("You've already voted in this poll!")
+        return self.cleaned_data
+
+    def save(self):
+        choice = self.cleaned_data['choices']
+        Choice.objects.filter(id=choice.id).update(votes=F('votes') + 1)
+        choice.voters.add(self.user)