django ManyToManyField serializer - django

Question

i'm new to django. The version i'm using is 1.11.2
I have a a schema like this.
There are many "designs" and each design can have any number of "patterns".
my design model is like below
from django.db import models
from products.models import Product
class Design(models.Model):
name = models.CharField(max_length=200)
product_id = models.ForeignKey(Product, on_delete=models.CASCADE)
price = models.CharField(max_length=200)
def __str__(self):
return self.name
My design serializer is like below
from rest_framework import serializers
from .models import Design
from rest_framework import serializers
from patterns.models import Pattern
class DesignsSerializer(serializers.ModelSerializer):
patterns = DesignPatternSerializer(read_only=True, many=True)
class Meta:
depth = 1
model = Design
fields = ('id','name','patterns')
read_only_fields = ('id','name','patterns')
The view for designs is as below
from django.shortcuts import render
from .models import Design
from .serializers import DesignsSerializer
from rest_framework import generics, filters
# Create your views here.
class ListDesignsByProducId(generics.ListCreateAPIView):
serializer_class = DesignsSerializer
def get_queryset(self):
return Design.objects.filter(product_id__exact = self.kwargs.get('product_id'))
My pattern model is like below.
from django.db import models
from datetime import date
from designs.models import Design
class Pattern(models.Model):
design_id = models.ManyToManyField(Design)
name = models.CharField(max_length=200)
def __str__(self):
return self.name
My pattern serializer is as below
from rest_framework import serializers
from .models import Pattern
class PatternSerializer(serializers.ModelSerializer):
class Meta:
depth = 1
model = Pattern
fields = ('id','design_id','name')
read_only_fields =('id','design_id','name')
Right now the api would return the details of the designs and it's associated products.
I would also like to get an array of patterns associated with the design.

Answer 1

In your DesignsSerializer you referred to the patterns by the name patterns without defining it in your models.
From the Django REST Framework documentation:
You'll normally want to ensure that you've set an appropriate
related_name argument on the relationship, that you can use as the
field name.
In your Pattern model:
class Pattern(models.Model):
design_id = models.ManyToManyField(Design, related_name='patterns')
...