Django drf serialiser map non pk field to object-CodePudding

I have Language model like this

class Language(models.Model):
    name = models.CharField()

class Post(models.Model)
    title = models.CharField()
    language = models.ForeignKey(Language, models.SET_DEFAULT, default=1) 

class PostSerializer(serializers.ModelSerializer):
     language = serializers.CharField(source='language.name')

class PostCreateAPIView(generics.ListCreateAPIView):
    serializer_class = serializers.PostSerializer

Post payload

{
 "title":"title_1",
 "language": "en" // instead of primary key
}

I wanted to map language name into object without using pk in payload.

CodePudding user response：

One way to do this is that, you pass the language with context to the serializer, and in the serializer, you use SerializerMethodField to get the pk/object using the language value.

class PostSerializer(serializers.ModelSerializer): language = serializers.SerializerMethodField()

 def get_language(self):
     return Language.objects.get(name=self.context["language_name"]) # return anything you want from here.

To pass serializer

serialized_data = PostSerializer(data, context={"language_name": self.request.data["language_name"]})

CodePudding user response：

Inside PostSerializer, change the representation of languge into SlugRelatedField and set slug field to 'name'. This accepts "name" from Language Model in PostSerializer language field.

class PostSerializer(serializers.ModelSerializer):

    class Meta:
    model = Post
    fields = ['title', 'languge']

    def get_fields(self):
    fields = super().get_fields()
    view = self.context.get('view')
    if view and view.action == 'create':
        fields['language'] = serializers.SlugRelatedField(slug_field='name', queryset=Language.objects.all())
    return fields