[PYTHON] Sometimes you want to access View information from Serializer with DRF (Django REST Framework)

Regardless of whether this is good or not, there are times when you want to access View information from Serializer. We use a convenient Mixin that can be used in such cases internally. The more you do, the stronger the bond between View and Serializer, so we recommend that you follow the usage and dosage __.

Anyway, it's the source code.

ViewAccessSerializerMixin

class ViewAccessSerializerMixin(object):

    def get_view_action(self):
        """
Access View action from Serializer
        """
        context = getattr(self, 'context')
        if not context:
            warnings.warn('The context does not exist in the serializer. The instance is created in an illegal way')
            return None
        return context.get('view').action

    def get_view_kw(self, key, default=None):
        """
Access view kwargs from Serializer
        """
        context = getattr(self, 'context')
        if not context:
            warnings.warn('The context does not exist in the serializer. The instance is created in an illegal way')
            return default
        return context.get('view').kwargs.get(key, default)

    def get_kwargs_object(self, key, model_class):
        """
Access kwargs from the Serializer, treat it as an id, and search for the specified model
        """
        obj = model_class.objects.get_or_none(id=int(self.get_view_kw(key, 0)))
        if obj:
            return obj

Access the view action

Mostly used in validation. I think there are probably better conditions. Like this.

class HogeSerializer(ViewAccessSerializerMixin, serializers.ModelSerializer):

    #Various omissions

    def validate(self, attrs):
        #Change the verification content depending on the action
        action_name = self.get_view_action()
        if action_name == "xxxx":
            pass
        else:
            pass

Access kwargs in View

Mostly used in SerializerMethodField.

class PostHistorySerializer(ViewAccessSerializerMixin, serializers.ModelSerializer):

    #Various omissions

    comments = serializers.SerializerMethodField()

    def get_comments(self, obj):
        return obj.comment.filter(user_id=self.get_view_kw("user_pk"))

Access kwargs in View, consider it an id, and search for the specified model

It's close to the combination of ↑, but it's a shortcut.

class UserSerializer(ViewAccessSerializerMixin, serializers.ModelSerializer):

    #Various omissions

    def validate(self, attrs):
        user = self.get_kwargs_object('user_pk', models.User)
        if user.is_ban():
          raise NotFound()
        pass

Basically, I use it like this. I hope you can use it conveniently.