[FIXED] Update Create Method in Django Rest Framework for two nested serializers

Issue

I've found many answers to similar questions but not to my specific one. I'm trying to update the Create Method for my serializer which has two nested serializers:

class TaskSerializer(serializers.ModelSerializer):
    products = ProductSerializer()
    prep = PrepSerializer()

    class Meta:
        model = Task
        fields = '__all__'

    def create(self, validated_data):           
        products_data = validated_data.pop('products')
        task = Task.objects.create(**validated_data)
        for products_data in products_data:
            Product.objects.create(task=task, **products_data)
        return task

I want to add the "prep" nested serializer in as well to be updated at the same time but I can't seem get the syntax right.

Any help, greatly appreciated.

Solution

It should work fine, I think you are missing many=True. Does this work? (Assuming and products and prep should be many)

And also assuming that your models are structured like this:

class Task(models.Model)
    #fields

class Product(models.Model)
    task = models.ForeignKey(Task, on_delete=models.CASCADE)

class Prep(models.Model)
    task = models.ForeignKey(Task, on_delete=models.CASCADE)

class TaskSerializer(serializers.ModelSerializer):
    products = ProductSerializer(many=True)
    preps = PrepSerializer(many=True)

    class Meta:
        model = Task
        fields = '__all__'

    def create(self, validated_data):           
        products_data = validated_data.pop('products')
        preps_data = validated_data.pop('preps')
        task = Task.objects.create(**validated_data)

        for products_data in products_data:
            Product.objects.create(task=task, **products_data)
        
        for prep_data in preps_data:
            Prep.objects.create(task=task, **prep_data)

        return task

Then you can send a request like:

{
    "products": [
        {"foo": "bar"}
    ],
    "preps": [
        {"foo": "bar"}
    ],
}

Answered By - Felix Eklöf