django REST ModelSerializer serialization issue

Question

Good morning everybody!

I've a problem with django REST ModelSerializer.

This is my serializer:

class TransactionPayOutSerializer(serializers.ModelSerializer):

    author = serializers.SlugRelatedField(queryset=Users.objects.all(), slug_field='unique_id', allow_null=True)
    wallet = serializers.SlugRelatedField(queryset=Wallet.objects.all(), slug_field='wallet_id')
    bank_account = serializers.SlugRelatedField(queryset=BankAccount.objects.all(), slug_field='bank_account_id')

    class Meta:
        model = PayOut
        fields = ('author', 'wallet', 'amount',
                  'currency', 'bank_account')


    def __init__(self, **kwargs):
        if 'instance' in kwargs:
            super(TransactionPayOutSerializer,self).__init__(kwargs.get('instance'))
        else:
            self.merchant = kwargs.pop('merchant')
            super(TransactionPayOutSerializer, self).__init__(**kwargs)

    def validate(self, data):
        print 'Inside serializer validate(), data:'
        print data
        wallet = data['wallet']
        user_wallet = UserWallets.objects.get(wallet=wallet) 
        if self.merchant != user_wallet.merchant:
            raise serializers.ValidationError("Wallet not found")
        wallet.fetch()
        if wallet.balance < data['amount']:
            raise serializers.ValidationError("Not enough founds in wallet") 
        return data

    def create(self, validated_data):
        print 'Inside TransactionPayOutSerializer create():'
        print 'Validated data:'
        print validated_data
        pay_out = PayOut(**validated_data)
        user_wallet = UserWallets.objects.get(wallet=validated_data['wallet'])
        pay_out.author = user_wallet.user
        pay_out.merchant = self.merchant
        pay_out.save()
        return pay_out

It works perfectly but my problem is:

When the serializer is used for a get request (serializer.data) it's perfect. But when the serializer is used for a post request (TransactionPayOutSerializer(data=request.DATA)) it absolutely wants the 'user' parameter in the JSON. What is the best way to keep serialzer.data return 'user' representation making TransactionPayOutSerializer(data=request.DATA) works without receiving 'user' as parameter inside JSON post request? I should use simple serializers instead of ModelSerializers?

Thanks in advance!

zxzak zxzak · Accepted Answer · 2015-07-31T09:03:34

Serializer Fields

read_only Set this to True to ensure that the field is used when serializing a representation, but is not used when creating or updating an instance during deserialization.

Defaults to False

write_only Set this to True to ensure that the field may be used when updating or creating an instance, but is not included when serializing the representation.

Defaults to False

django REST ModelSerializer serialization issue

1 Answers