flows: FlowStageBinding group Stage by type

passbook/flows/forms.py

@@ -3,7 +3,8 @@
 from django import forms
 from django.utils.translation import gettext_lazy as _
 
-from passbook.flows.models import Flow, FlowStageBinding
+from passbook.flows.models import Flow, FlowStageBinding, Stage
+from passbook.lib.widgets import GroupedModelChoiceField
 
 
 class FlowForm(forms.ModelForm):
@@ -35,6 +36,8 @@ class FlowForm(forms.ModelForm):
 class FlowStageBindingForm(forms.ModelForm):
     """FlowStageBinding Form"""
 
+    stage = GroupedModelChoiceField(queryset=Stage.objects.all().select_subclasses(),)
+
     class Meta:
 
         model = FlowStageBinding