title: Nested objects save in DRF
body: <p>Models:</p>
  
  <pre><code>class Owner(models.Model):
      name = models.CharField(max_length=255)
  
      def __unicode__(self):
          return self.name
  
  class SomeThing(models.Model):
      own_id = models.IntegerField(unique=True)
      description = models.CharField(max_length=255, blank=True)
      owner = models.ForeignKey(Owner, blank=True, null=True)
  
  def __unicode__(self):
      return self.description
  </code></pre>
  
  <p>Serializers:</p>
  
  <pre><code>class OwnerNameField(serializers.RelatedField):
      def to_internal_value(self, data):
          pass
  
      def to_representation(self, value):
          return value.name
  
      def get_queryset(self):
          queryset = self.queryset
          if isinstance(queryset, (QuerySet, Manager)):
              queryset = queryset.all()
          lista = [Owner(name="------------")]
          lista.extend(queryset)
          return lista
  
  class OwnerSerializer(serializers.HyperlinkedModelSerializer):
      class Meta:
          model = Owner
          fields = ('name', 'id')
  
  class ThingSerializer(serializers.ModelSerializer):
      owner = OwnerNameField(queryset=Owner.objects.all())
  
      class Meta:
          model = SomeThing
          fields = ('own_id', 'description', 'owner')
  </code></pre>
  
  <p>Basically it works as intended. But when i add some fields to <strong>Owner</strong> class i would like to see all these fields in output of <strong>ThingSerializer</strong> (and be able to parse them - string doesn't suit here). I could change field <strong>owner</strong> to <code>owner = OwnerSerializer()</code> which gives me what i need. But when i want to add <strong>SomeThing</strong> object (tested in API browser) i also need add new <strong>Owner</strong> object - and i don't want it, i want use existing <strong>Owner</strong> object. How can i achieve it?</p>