CODEWITHSUNDEEP
djangodjango-rest-framework
Dunaevsky Maxim
Dunaevsky Maxim

Reputation: 3199

Django REST Framework (DRF): Set current user id as field value

I have model NewsModel and 2 serializers for him:

models.py

class NewsModel(models.Model):
    title = models.CharField('Заголовок', max_length=255, help_text='Максимальная длина - 255 символов')
    announce = models.TextField('Анонс', help_text='Краткий анонс новости')
    author = models.ForeignKey(settings.AUTH_USER_MODEL, help_text='Автор новости', related_name='news')
    full_text = models.TextField('Полный текст новости', help_text='Полный текст новости')
    pub_date = models.DateTimeField('Дата публикации', auto_now_add=True, default=timezone.now, help_text='Дата публикации')

    def comments_count(self):
        return NewsComment.objects.filter(news=self.id).count()

    def get_author_full_name(self):
        return self.author.get_full_name()

    class Meta:
        db_table = 'news'
        ordering = ('-pub_date',)

serilizers.py:

from rest_framework import serializers
from .models import NewsModel
from extuser.serializers import UserMiniSerializer

class NewsReadSerializer(serializers.ModelSerializer):

    author = UserMiniSerializer()

    class Meta:
        model = NewsModel
        fields = ('id', 'title', 'announce', 'comments_count', 'reviews', 'author_name')

    def get_author_full_name(self, obj):
        return obj.get_author_full_name()


class NewsWriteSerializer(serializers.ModelSerializer):

    def validate_author(self, value):
        value = self.request.user.id
        return value

    class Meta:
        model = NewsModel

I select serializers in the api.py:

class NewsList(ListCreateAPIView):
    queryset = NewsModel.objects.order_by('-pub_date')
    def get_serializer_class(self, *args, **kwargs):
        if self.request.method == 'GET':
            return NewsReadSerializer
        return NewsWriteSerializer

    class Meta:
        model = NewsModel

But when I will create NewsModel item, I see Error 400: Bad request [{'author': 'This field is required'}]

How I can set current user id as NewsItem.author value on creating new item?

Upvotes: 21

Views: 20315

Answers (4)

Dunaevsky Maxim
Dunaevsky Maxim

Reputation: 3199

In DRF version prior 3 field must be declader with allow_null=True and default=None. DRF don't run checking fields without this params. Result code:

class NewsReadSerializer(serializers.ModelSerializer):

    """
    Serializer only for reading.

    author field serialized with other custom serializer
    """

    author = UserMiniSerializer()

    class Meta:
        model = NewsModel
        fields = ('id', 'title', 'announce', 'comments_count', 'reviews', 'author', 'pub_date',)


class NewsWriteSerializer(serializers.ModelSerializer):

    """
    Serializer for creating and updating records.

    author here is the instance of PrimaryKeyRelatedField, linked to all users
    """

    author = serializers.PrimaryKeyRelatedField(
        queryset=User.objects.all(), # Or User.objects.filter(active=True)
        required=False, 
        allow_null=True, 
        default=None
    )

    # Get the current user from request context
    def validate_author(self, value):
        return self.context['request'].user

    class Meta:
        model = NewsModel      
        fields = ('title', 'announce', 'full_text', 'author',)

Upvotes: 8

TIO
TIO

Reputation: 331

In new DRF you can write

owner = serializers.HiddenField(
    default=serializers.CurrentUserDefault()
)

See http://www.django-rest-framework.org/api-guide/validators/#currentuserdefault

Upvotes: 14

Rodrigo Prior Bechelli
Rodrigo Prior Bechelli

Reputation: 81

I would try something like this:

your models.py

class NewsModel(models.Model):
    title = models.CharField(
        'Заголовок', max_length=255,
        help_text='Максимальная длина - 255 символов')
    announce = models.TextField('Анонс',
        help_text='Краткий анонс новости')
    author = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        help_text='Автор новости', related_name='news')
    full_text = models.TextField(
        'Полный текст новости',
        help_text='Полный текст новости')
    pub_date = models.DateTimeField(
        'Дата публикации', auto_now_add=True,
        default=timezone.now, help_text='Дата публикации')

def comments_count(self):
    return NewsComment.objects.filter(news=self.id).count()

def get_author_full_name(self):
    return self.author.get_full_name()

class Meta:
    db_table = 'news'
    ordering = ('-pub_date',)

serializers.py

(ref.: http://www.django-rest-framework.org/api-guide/validators/#currentuserdefault)

from <yourapp>.models import NewsModel
from rest_framework import serializers


class NewsModelSerializer(serializers.ModelSerializer):
    author = serializers.HiddenField(default=serializers.CurrentUserDefault())
    class Meta:
        model = NewsModel

Also you should set settings.py to something like this:

REST_FRAMEWORK = {
    'DEFAULT_PERMISSION_CLASSES': (
        'rest_framework.permissions.IsAuthenticated',)
}

Upvotes: 5

mariodev
mariodev

Reputation: 15509

I don't think you're using the serializer properly. A better practice to set request related data is to override perform_create in your view:

def perform_create(self, serializer):
    serializer.save(author=self.request.user)

def perform_update(self, serializer):
    serializer.save(author=self.request.user)

and then set your author serializer to read-only:

author = UserMiniSerializer(read_only=True)

this way you can simply use one single NewsSerializer for both read and write actions.

Upvotes: 34

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