Ensure instance/validated_data links are iterable

program/serializers.py

@@ -158,11 +158,13 @@ class HostSerializer(serializers.ModelSerializer):
         instance.image = validated_data.get('image', instance.image)
         instance.ppoi = validated_data.get('ppoi', instance.ppoi)
 
-        for link in instance.links.all():
-            link.delete(keep_parents=True)
+        if instance.links.count() > 0:
+            for link in instance.links.all():
+                link.delete(keep_parents=True)
 
-        for link_data in validated_data.get('links'):
-            Link.objects.create(host=instance, **link_data)
+        if links := validated_data.get('links'):
+            for link_data in links:
+                Link.objects.create(host=instance, **link_data)
 
         instance.save()