DRF: how to join many-to-many field into a string in json - react-native

Question

models.py
class SalesPerson(models.Model):
name = models.CharField(max_length=50)
office = models.ForeignKey(Location, on_delete=models.SET_NULL, null=True)
class Project(models.Model):
title = models.CharField(max_length=50)
leader = models.ForeignKey(SalesPerson, on_delete=models.SET_NULL, null=True,related_name='leader')
location = models.ForeignKey(Location, on_delete=models.SET_NULL, null=True)
product = models.ManyToManyField(Product)
sales_person = models.ManyToManyField(SalesPerson)
serializers.py
class ProjectSerializer(serializers.ModelSerializer):
leader_name= serializers.ReadOnlyField(source='leader.name')
location_name= serializers.ReadOnlyField(source='location.name')
product = serializers.SlugRelatedField(read_only=True, slug_field='name', many=True)
sales_person = serializers.SlugRelatedField(read_only=True, slug_field='name', many=True)
class Meta:
model = Project
fields = ('id', 'title', 'leader_name', 'location_name', 'product', 'sales_person')
class SPSerializer(serializers.ModelSerializer):
projects = ProjectSerializer(many=True, read_only=True, source='project_set')
office_name= serializers.ReadOnlyField(source='office.city')
class Meta:
model = SalesPerson
fields = ('id', 'name', 'office_name', 'email', 'projects')
result:
{
"id": 2,
"name": "Angela",
"office_name": "NSW Sydney",
"email": "angela#angela.com",
"projects": [
{
"id": 1,
"title": "Mall Orchid",
"leader_name": "Boris",
"product": [
"Split wall mounted"
],
"sales_person": [
"Angela",
"Boris",
"David"
],
},
{
"id": 6,
"title": "Mall Petunia",
"leader_name": "Boris",
"product": [
"Split duct"
],
"sales_person": [
"Angela",
"Boris",
"David"
],
},
]
},
I am going to consume the json using react native
I know how to iterate over "projects"
However, I want to avoid iterating over "sales_person" to make rendering the array simpler
So I am sure I have to make the sales_person into a string but after googling for many hours today, I can't find an answer
I am hoping to do this in Django Rest Framework and not in Expo React Native, if possible
So in short, I want to make the result like this:
{
"id": 2,
"name": "Angela",
"office_name": "NSW Sydney",
"email": "angela#angela.com",
"projects": [
{
"id": 1,
"title": "Mall Orchid",
"leader_name": "Boris",
"product": [
"Split wall mounted"
],
"sales_person": "Angela", "Boris", "David",
},
{
"id": 6,
"title": "Mall Petunia",
"leader_name": "Boris",
"product": [
"Split duct"
],
"sales_person": "Angela", "Boris", "David",
},
]
},
Thank you so much for your help.

Answer 1

I've found the answer
I am writing it for my own future reference
class ProjectSerializer(serializers.ModelSerializer):
leader_name= serializers.ReadOnlyField(source='leader.name')
location_name= serializers.ReadOnlyField(source='location.city')
product = serializers.SlugRelatedField(read_only=True, slug_field='name', many=True)
sales_person = serializers.SerializerMethodField('get_sales_person')
class Meta:
model = Project
fields = ('id', 'title', 'leader_name', 'location_name', 'product', 'sales_person')
def get_sales_person(self, obj):
return ', '.join([sales_person.name for sales_person in obj.sales_person.all()])