Creating new objects when depth is specified in Meta class.

[aasutossh]

My models:

class Snippet(models.Model):
    value = models.CharField(max_length=1000)


class List(models.Model):
    name = models.CharField(max_length=200)
    user = models.ForeignKey(User, on_delete=models.CASCADE)


class ListItems(models.Model):
    snippet = models.ForeignKey(Snippet, on_delete=models.CASCADE)
    related_list = models.ForeignKey(List, on_delete=models.CASCADE, null=True, blank=True)
    name = models.CharField(max_length=50)

serializers.py

class SnippetSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = Snippet
        fields = "__all__"


class ListItemsSerializer(serializers.ModelSerializer):
    class Meta:
        model = ListItems
        fields = "__all__"
        depth = 2


class ListSerializer(WritableNestedModelSerializer):
    listitems_set = ListItemsSerializer(many=True)
    class Meta:
        model = List
        fields = "__all__"

views.py

class SnippetViewSet(viewsets.ModelViewSet):
    queryset = Snippet.objects.all()
    serializer_class = SnippetSerializer


class ListViewSet(viewsets.ModelViewSet):
    queryset = List.objects.all()
    serializer_class = ListSerializer


class ListItemsViewSet(viewsets.ModelViewSet):
    queryset = ListItems.objects.all()
    serializer_class = ListItemsSerializer

POSTing data like these to ListSerializer:

{
  "listitems_set": [
    {
      "name": "item5",
      "snippet": 1
    },
    {
      "name": "item6",
      "snippet": 1
    }
  ],
    "name": "Third List",
    "user": 1
}

results in error

IntegrityError at /list/
NOT NULL constraint failed: list_listitems.snippet_id

But the List is created without the listitem_set.
If I comment out depth=2 in the ListItemsSerializer it works fine.

I've enabled the depth option because I get all the related data at once, instead of fetching each and every data manually.

Let me know if something is unclear, or if I've made a mistake.

[ruscoder]

Hello @aasutossh! I believe this case wasn't covered in this library yet. As a workaround, I can suggest you implement two serializers: the first for creating/updating and the second for reading.