Add event update serializer

webapp/serializers.py

@@ -25,11 +25,20 @@ class EventSerializer(serializers.HyperlinkedModelSerializer):
     def create(self, validated_data):
         signupForms = validated_data.pop('signupForm')
         event = Event.objects.create(**validated_data)
-        for signupForm in signupForms:
-            event.signupForm.add(signupForm)
+        for form in signupForms:
+            event.signupForm.add(form)
         event.save()
         return event
 
+    def update(self, instance, validated_data):
+        signupForms = validated_data.pop('signupForm')
+        instance = super(EventSerializer, self).update(instance, validated_data)
+        instance.signupForm.clear()
+        for form_data in signupForms:
+            # form_qs = SignupForms.objects.filter(id=form['id'])
+            instance.signupForm.add(form_data)
+        return instance
+
 
 class SignupSerializer(serializers.ModelSerializer):
     class Meta: