python - Django Rest Framework - Get related model field in serializer

51
votes

I'm trying to return a HttpResponse from Django Rest Framework including data from 2 linked models. The models are:

class Wine(models.Model):

    color = models.CharField(max_length=100, blank=True)
    country = models.CharField(max_length=100, blank=True)
    region = models.CharField(max_length=100, blank=True)
    appellation = models.CharField(max_length=100, blank=True)

class Bottle(models.Model):

    wine = models.ForeignKey(Wine, null=False)
    user = models.ForeignKey(User, null=False, related_name='bottles')

I'd like to have a serializer for the Bottle model which includes information from the related Wine.

I tried:

class BottleSerializer(serializers.HyperlinkedModelSerializer):
    wine = serializers.RelatedField(source='wine')

    class Meta:
        model = Bottle
        fields = ('url', 'wine.color', 'wine.country', 'user', 'date_rated', 'rating', 'comment', 'get_more')

which doesn't work.

Any ideas how I could do that?

Thanks :)

2
pythondjangoserializationforeign-keysdjango-rest-framework
Thanks for this, I'm almost there. What @tom-christie explains works to get the object itself but I'm unable to get all the fields from the Wine object.. - bpipat
Try source='*' as RelatedField argument. - mariodev
I still get the unicode name in the result of the query. And trying wine.color in the fields doesn't work What does source='*' change? - bpipat

2 Answers

64
votes

Simple as that, adding the WineSerializer as a field solved it. 

class BottleSerializer(serializers.HyperlinkedModelSerializer):
    wine = WineSerializer(source='wine')

    class Meta:
        model = Bottle
        fields = ('url', 'wine', 'user', 'date_rated', 'rating', 'comment', 'get_more')

with: 

class WineSerializer(serializers.HyperlinkedModelSerializer):

    class Meta:
        model = Wine
        fields = ('id', 'url', 'color', 'country', 'region', 'appellation')

Thanks for the help @mariodev :)

18
votes

If you want to get specific field you can use Serializer Fields

https://www.django-rest-framework.org/api-guide/fields/

    class BottleSerializer(serializers.HyperlinkedModelSerializer):
        winecolor = serializers.CharField(read_only=True, source="wine.color")

        class Meta:
            model = Bottle
            fields = ('url', 'winecolor', 'user', 'date_rated', 'rating', 'comment', 'get_more')