CODEWITHSUNDEEP
pythondjangodjango-rest-frameworkdjango-viewsdjango-serializer
Omar Jandali
Omar Jandali

Reputation: 824

Customize the return object from django rest framework serializer

I want to customize the django rest framework serializer return object to a specific requirement. right now it returns the fields in a single object that is not nested. 

{
    "id": 9,
    "namespace": "steve",
    "path": "something/another",
    "value": "this is a value"
},

and this is what I want the outcome to look like:

{
    "id": 6,
    "namespace": "tempnamespaced",
    "path": "randompath",
    "value": "anothertest",
    "user": {
        "userId": "testUser1"
    }
}

So i want to add a nested object named user and add the userID value within the user.

the data that is returned in the userId is actually person.username person is a model username so the data is going to look like this when it is assigned and returned:

"user": {
    "userId": {{person.username}}
}

I will attach mmy code below:

serializer:

from rest_framework import serializers
from .models import Preference
from django.contrib.auth.models import User


class PreferenceSerializer(serializers.ModelSerializer):
    # person = serializers.PrimaryKeyRelatedField(queryset=User.objects.all(),)

    class Meta:
        model = Preference
        fields = ('id', 'namespace', 'path', 'value')

here is the get viewset:

    @permission_classes((IsAuthenticated))
    def get_queryset(self):
        namespace = self.kwargs.get('namespace', None)
        path = self.kwargs.get('path', None)
        if namespace is None and path is None:
            queryset = Preference.objects.all().filter(user_id=1)
        if namespace and path is None:
            queryset = Preference.objects.all().filter(user_id=1, namespace=namespace)
        if namespace and path:
            queryset = Preference.objects.all().filter(user_id=1, namespace=namespace, path=path)
        return queryset

here is the mode:

from django.db import models
from django.contrib.auth.models import User
from owf_framework.people.models import Person

class Preference(models.Model):
    id = models.BigAutoField(primary_key=True, null=False)
    version = models.BigIntegerField(default=1, null=False)
    path = models.CharField(max_length=200, null=False)
    namespace = models.CharField(max_length=200, null=False)
    value = models.TextField(null=False)
    user_id = models.BigIntegerField(null=False, default=1)
    person = models.ForeignKey(User, on_delete=models.CASCADE)

    def __str__(self):
        return self.namespace

    class Meta:
        db_table = 'preference'

Upvotes: 1

Views: 3619

Answers (2)

Tsang-Yi Shen
Tsang-Yi Shen

Reputation: 542

Define to_representation() in your serializer:

class PreferenceSerializer(serializers.ModelSerializer):
    # person = serializers.PrimaryKeyRelatedField(queryset=User.objects.all(),)

    class Meta:
        model = Preference
        fields = ('id', 'namespace', 'path', 'value')

    def to_representation(self, instance):
        ret = super().to_representation(instance)
        ret['user'] = {'userId': instance.person.username}
        return ret

Upvotes: 4

user11751463
user11751463

Reputation:

You can add a method to your model to return the username instead of the field name.

class Preference(models.Model):
    id = models.BigAutoField(primary_key=True, null=False)
    version = models.BigIntegerField(default=1, null=False)
    path = models.CharField(max_length=200, null=False)
    namespace = models.CharField(max_length=200, null=False)
    value = models.TextField(null=False)
    user_id = models.BigIntegerField(null=False, default=1)
    person = models.ForeignKey(User, on_delete=models.CASCADE)

    def __str__(self):
        return self.namespace

    def get_username(self):
        return self.person.username

    class Meta:
        db_table = 'preference'

The Serializer can now use this method.

class PreferenceSerializer(serializers.ModelSerializer):
    person = serializers.PrimaryKeyRelatedField(queryset=User.objects.all(),)

    class Meta:
        model = Preference
        fields = ('id', 'namespace', 'path', 'value', 'person', 'get_username')

Upvotes: 0

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