Agfdhyk

I have 4 models. User, Question, Choice, and Voting. This is basically a polls app I'm trying to create. A question can have many choices. The Voting model tracks what each user chose as their answer.

What I'd like to do is retrieve all the questions and also check what choice the logged in user selected for each question. Here's the models:

class Question(models.Model):

    user            = models.ForeignKey(User, on_delete=models.CASCADE)

    status          = models.CharField(max_length=200)

    total_votes     = models.IntegerField(default=0)



class Choice(models.Model):

    question    = models.ForeignKey(Question, on_delete=models.CASCADE)

    choice      = models.CharField(max_length=120)

    vote_count  = models.IntegerField(default=0)



class Voting(models.Model):

    user    = models.ForeignKey(User, on_delete=models.CASCADE)

    choice  = models.ForeignKey(Choice, on_delete=models.CASCADE)

Here's how I want the data displayed:

{

    user: 2

    status: "Hello"

    total_votes: 101

    choices: [

                {

                    "id": 2,

                    "choice": "first choice",

                    "vote_count": 31,

                    "question": 3

                },

                {

                    "id": 4,

                    "choice": "second choice",

                    "vote_count": 70,

                    "question": 3

                }

            ],

    choice_selected: 2

}

In the data above, the logged in user selected choice 2 in this specific question.

Edit: My attempt to add serializer, but displays Object of type 'Voting' is not JSON serializable

class ChoiceSerializer(serializers.ModelSerializer):

    class Meta:

        model = Choice

        fields = '__all__'



class QuestionSerializer(serializers.ModelSerializer):

    choices = ChoiceSerializer(source='choice_set', many=True)

    class Meta:

        model = Question

        fields = '__all__'





class GetProfileQuestions(ListAPIView):

    serializer_class = QuestionSerializer



    def get_queryset(self):

        return Question.objects.all()

This query successfully prints out each question and its choices. However, how do I make it so that it also prints out which choice the user selected for each question?

class VotingSerializer(serializers.ModelSerializer):



    class Meta:

        model = Voting

        fields = '__all__'    





class ChoiceSerializer(serializers.ModelSerializer):

    votes = VotingSerializer(source='voting_set', many=True)

    class Meta:

        model = Choice

        fields = '__all__'





class QuestionSerializer(serializers.ModelSerializer):

    choices = ChoiceSerializer(source='choice_set', many=True)

    choice_selected = serializers.SerializerMethodField()

    class Meta:

        model = Question

        fields = '__all__'



    def get_choice_selected(self, obj):

        choice_selected = Voting.objects.filter(choice__question=obj.id).filter(user=obj.user)

        return choice_selected

I think you will want this in your QuestionSerializer class

 choice_selected = serializers.SerializerMethodField()

and define a method that looks something like this in QuestionSerializer …

def get_choice_selected(self, obj):

        choice_selected = Voting.objects.filter(choice__question=obj.id).filter(user=obj.user)

        return choice_selected

The above is untested.