Reworked some account views

accounts/forms.py

@@ -0,0 +1,30 @@
+from django.forms import ModelForm, ValidationError
+from django.utils.translation import ugettext_lazy as _
+
+from appsettings.models import AppSettings
+
+from .models import UserInstance
+
+
+class UserInstanceForm(ModelForm):
+    def __init__(self, *args, **kwargs):
+        super(UserInstanceForm, self).__init__(*args, **kwargs)
+
+        # Make user and instance fields not editable after creation
+        instance = getattr(self, 'instance', None)
+        if instance and instance.id is not None:
+            self.fields['user'].disabled = True
+            self.fields['instance'].disabled = True
+
+    def clean_instance(self):
+        instance = self.cleaned_data['instance']
+        if AppSettings.objects.get(key="ALLOW_INSTANCE_MULTIPLE_OWNER").value == 'False':
+            exists = UserInstance.objects.filter(instance=instance)
+            if exists:
+                raise ValidationError(_('Instance owned by another user'))
+
+        return instance
+
+    class Meta:
+        model = UserInstance
+        fields = '__all__'