Fixes #26, cleanup form validation issues.

Due to the way the validation worked, all cleanup() functions are ran before
the errors are returned. If the username didn't exist the existing user
lookup failed.

sso/forms.py

@@ -25,19 +25,6 @@ class EveAPIForm(forms.Form):
         else:
             raise forms.ValidationError("This API User ID is already registered")
 
-class ServiceUsernameField(forms.CharField):
-    """ Extension of a CharField, does extra validation on username format and
-        also checks the username is free with ServiceAccount model """
-
-    def clean(self, request, initial=None):
-        field = super(ServiceUsernameField, self).clean(request)
-
-        # Checks that usernames consist of letters and numbers only
-        if not re.match("^[A-Za-z0-9_-]*$", field):
-            raise forms.ValidationError("Invalid character in username, use letters and numbers only")
-
-        return field
-
 def UserServiceAccountForm(user):
     """ Generate a Service Account form based on the user's permissions """
 
@@ -47,13 +34,23 @@ def UserServiceAccountForm(user):
         """ Service Account Form """
 
         service = forms.ModelChoiceField(queryset=services)
-        username = ServiceUsernameField(min_length=4,max_length=50)
+        username = forms.CharField(min_length=4,max_length=50)
         password = forms.CharField(label = u'Password',widget = forms.PasswordInput(render_value=False)) 
 
+        def clean_username(self):
+            field = self.cleaned_data.get('username', '')
+
+            # Checks that usernames consist of letters and numbers only
+            if not re.match("^[A-Za-z0-9_-]*$", field):
+                raise forms.ValidationError("Invalid character in username, use letters and numbers only")
+
+            return field
+
+
         def clean(self):
             try:
                 acc = ServiceAccount.objects.get(service_uid=self.cleaned_data['username'],service=self.cleaned_data['service'])
-            except ServiceAccount.DoesNotExist:
+            except (ServiceAccount.DoesNotExist, KeyError):
                 pass
             else:
                 raise forms.ValidationError("That username is already taken")