How can I serialize None from db to empyt object?

Question

I have the following models:

class ContentUpload(BaseModel):
    ...
    status = models.ForeignKey(CourseStatus, on_delete=models.CASCADE, related_name="content_status", null=True, blank = True)

class CourseStatus(BaseModel):
    status_name = models.CharField(max_length=250)
    slug = models.SlugField()

    def save(self, *args, **kwargs):
        self.slug = slugify(self.status_name)
        super(CourseStatus, self).save(*args, **kwargs)

    def __str__(self):
        return str(self.status_name)

The following serializers:

class CourseStatusListSerializers(serializers.ModelSerializer):
    class Meta:
        model = CourseStatus
        fields = ('id', 'status_name', 'slug')

    def get_status(self, obj):
        return CourseStatusListSerializers(obj.status, context={"request": self.context['request']}).data

When the ContentUpload.status is None it returns the following:

"status":{"status_name":"","slug":""}

My question is that how can I do it to give back an empty object? What is your best practice for this?

"status":{}

Answer 1

1- Rewrite your ContentUploadSerializer to the following:

class ContentUploadSerializer(serializers.ModelSerializer):
    status = CourseStatusListSerializers(required=False)
    class Meta:
        model = ContentUpload
        fields = ('id', 'status',)

2- Remove the get_status method.

The serialized ContentUpload object with the status field None will be as follows:

  {
    "id": 2,
    "status": null
  }

And with the status field not None it will be:

  {
    "id": 1,
    "status": {
      "id": 1,
      "status_name": "Pending",
      "slug": "pending"
    }
  }

You can read more about the nested serializers from this page. https://www.django-rest-framework.org/api-guide/serializers/#dealing-with-nested-objects