Agfdhyk

I would like to add an additional field for user's details. But it has to use another value outside of database fields.
For more clearly like this

model:

class User(models.Model):

    id= models.AutoField(primary_key=True)

    last_name= models.CharField(max_length=20)

    first_name=models.CharField(max_length=20)

    role_id = models.IntegerField()

serializer:

class UserSerializer(serializers.ModelSerializer):

    display_summary = serializers.SerializerMethodField()

    login_user_id = serializers.IntegerField(required=False)



    class Meta:

        model = User

        fields = ("id","last_name","first_name", "display_summary", "login_user_id")



    def get_display_summary(self, obj):

        login_id    = self.validated_data.get('login_user_id', None)

        login_user  = User.objects.filter(pk=login_id).first()

        if obj.role_id==2 and login_user.role_id==1:

            return 1



        return 0

So in my views, when getting just one user, it's all ok:

@api_view(['GET'])

@login_required

def get_user(request, login_user, user_id):

    serializer = UserSerializer(User.objects.get(pk=user_id), data={'login_user_id': login_user.id})

    if serializer.is_valid():

        result = serializer.data

        return Response(result, status=status.HTTP_200_OK)



#result:

#{

#    "id": 2,

#    "last_name": "V",

#    "first_name": "Lich",

#    "role_id": 2,

#    "display_summary": 1

#}

But when I need to return a list, how can I add additional data (login_user_id)?
This is not working:

users = User.objects.filter(last_name__icontains='v')

result_serializer = UserSerializer(users, data={'login_user_id': login_user.id}, many=True)

return result_serializer.data

The error occur say that it's looking for a list, not a dict for inputted param.

Based on @Hai Lang 's idea, I made a new namedtuple to add more info. Something like this:

Serializer:
No use ModelSerializer, use normal Serializer with field I would like to show on this view

class UserSummarySerializer(serializers.Serializer):

    user_id = serializers.SerializerMethodField()

    last_name = serializers.SerializerMethodField()

    first_name = serializers.SerializerMethodField()

    display_summary = serializers.SerializerMethodField()



    def validate(self, data):

        #some validation if needed

        return data

    def get_user_id(self, obj):

        return obj.user.user_id

    def get_last_name(self, obj):

        return obj.user.last_name

    def get_first_name(self, obj):

        return obj.user.first_name

    def get_display_summary(self, obj):

        login_user  = obj.login_user

        if obj.role_id==2 and login_user.role_id==1:

            return 1



        return 0

then in my views:

userSummary = namedtuple('userSummary ', ('user', 'login_user'))

users = User.objects.filter(last_name__icontains='v')

objs  = [userSummary(u, login_user) for u in users]

result_serializer = UserSerializer(objs, many=True)

return result_serializer.data