How to use pre_save methods in rest_framework serializers? - django

Question

I know this is a noob question about DRF. I use latest version of Django and DRF. In my Django , I create slugs in a method using pre_save signals.
def create_slug(instance, new_slug=None):
slug = slugify(instance.title)
if new_slug is not None:
slug = new_slug
qs = Article.objects.filter(slug=slug).order_by("-id")
exists = qs.exists()
if exists:
new_slug = "%s-%s" %(slug, qs.first().id)
return create_slug(instance, new_slug = new_slug)
return slug
#receiver(pre_save, sender = Article)
def pre_save_article_receiver(sender, instance, raw, using, **kwargs):
if not instance.slug:
instance.slug = create_slug(instance)
pre_save.connect(pre_save_article_receiver, sender=Article)
Then I can manage to write my views and serializers using DRF
from rest_framework import serializers
from yogavidya.apps.articles.models import Article
class ArticleSerializer(serializers.ModelSerializer):
class Meta:
model = Article
fields = [
"title",
"user",
"content",
"excerpt",
]
--views.py--
app_name = 'articles'
class ArticleListView(generics.ListCreateAPIView):
lookup_field = 'pk'
serializer_class = ArticleSerializer
queryset = Article.objects.all()
def list(self, request):
# Note the use of `get_queryset()` instead of `self.queryset`
queryset = self.get_queryset()
serializer = ArticleSerializer(queryset, many=True)
print(serializer.data)
return Response(serializer.data)
def get_queryset(self):
return Article.objects.all()
def get_object(self):
pk = self.kwargs.get("pk")
return Article.objects.get(pk=pk)
def put(self, request, *args, **kwargs):
return self.update(request, *args, **kwargs)
class ArticleViewSet(viewsets.ModelViewSet):
"""
API endpoint that allows users to be viewed or edited.
"""
queryset = Article.objects.all().order_by('-title')
serializer_class = ArticleSerializer
When I post my form I get name 'create_slug' is not defined. Where is best place to override my save method and updates? can you help me ?
Thanks

Answer 1

I guess error is due to the wrong indentation of def create_slug
Class Xyz:
...
...
def create_slug(instance, new_slug=None):
slug = slugify(instance.title)
if new_slug is not None:
slug = new_slug
qs = Article.objects.filter(slug=slug).order_by("-id")
exists = qs.exists()
if exists:
new_slug = "%s-%s" %(slug, qs.first().id)
return create_slug(instance, new_slug = new_slug)
return slug
It is not a class function, so it should be outside class.