Added SuccessMessageMixin (#74)

Closes #73

Author: bahattincinic

people/views.py

@@ -1,25 +1,21 @@
 # coding: utf-8
 
-from django.contrib import messages
 from django.urls import reverse
 from django.views.generic import ListView, CreateView
 
 from people.models import Person
 from people.forms import PersonForm
+from pyist.mixins import SuccessMessageMixin
 
 
 class PeopleView(ListView):
     queryset = Person.objects.active()
 
 
-class CreatePeopleView(CreateView):
+class CreatePeopleView(SuccessMessageMixin, CreateView):
     model = Person
     form_class = PersonForm
     success_message = 'Kişi başarıyla eklendi.'
 
-    def form_valid(self, form):
-        messages.success(self.request, self.success_message)
-        return super(CreatePeopleView, self).form_valid(form)
-
     def get_success_url(self):
         return reverse("people:index")

pyist/mixins.py

@@ -0,0 +1,14 @@
+from django.contrib import messages
+from django.core.exceptions import ImproperlyConfigured
+
+
+class SuccessMessageMixin:
+    success_message = None
+
+    def form_valid(self, form):
+        if not self.success_message:
+            raise ImproperlyConfigured(
+                'No message to show. Provide a success_message.'
+            )
+        messages.success(self.request, self.success_message)
+        return super().form_valid(form)