I've got a problem with adding a serializer to another serializer and call it correctly.
My models.py with just the WorkshopMaterials Model
class AmountType(models.TextChoices):
PCT = "PCT", _("Piece")
BOX = "BOX", _("Box")
KG = "KG", _("Kilogram")
class Material(models.Model):
class Status(models.TextChoices):
STORED = "STORED", _("Stored")
ORDERED = "ORDERED", _("Ordered")
NEEDED = "NEEDED", _("Needed")
id = models.BigAutoField(primary_key=True)
name = models.CharField(max_length=255, blank=False)
amount = models.IntegerField(blank=False, default=1)
amountType = models.CharField(
max_length=3,
choices=AmountType.choices,
default=AmountType.PCT,
blank=False
)
link = models.URLField(max_length=255, blank=True)
status = models.CharField(max_length=7, choices=Status.choices, default=Status.STORED, blank=False)
class WorkshopMaterials(models.Model):
id = models.BigAutoField(primary_key=True)
workshop = models.ForeignKey(Workshop, on_delete=models.CASCADE, related_name="workshop")
material = models.ForeignKey(Material, on_delete=models.CASCADE, related_name="material")
amount = models.IntegerField(blank=False, default=1)
amountType = models.CharField(
max_length=3,
choices=AmountType.choices,
default=AmountType.PCT,
blank=False
)
My serializer.py
class MaterialSerializer(ModelSerializer):
class Meta:
model = Material
fields = ('id', 'name', 'amount', 'amountType', 'link', 'status')
extra_kwargs = {'id': {'read_only': True}}
class WorkshopMaterialsSerializer(ModelSerializer):
class Meta:
model = WorkshopMaterials
fields = ('amount', 'amountType', 'material', 'workshop')
def to_representation(self, instance):
rep = super().to_representation(instance)
rep["material"] = MaterialSerializer(instance.material).data["name"]
rep["workshop"] = WorkshopSerializer(instance.workshop).data["id"]
return rep
class WorkshopSerializer(ModelSerializer):
class Meta:
model = Workshop
exclude = ['created_at', 'updated_at']
def __init__(self, *args, **kwargs):
fields = kwargs.pop('fields', None)
super().__init__(*args, **kwargs)
if fields is not None:
allowed = set(fields)
existing = set(self.fields)
for field_name in existing - allowed:
self.fields.pop(field_name)
def to_representation(self, instance):
rep = super().to_representation(instance)
workshopLeaderData = WorkshopLeaderSerializer(instance.leader).data
workshopLeaderName = workshopLeaderData["name"]
if workshopLeaderData["displayname"] == "AN":
workshopLeaderName = workshopLeaderData["artistname"]
rep["leader"] = workshopLeaderName
return rep
My views.py
class MaterialListView(APIView):
permission_classes = (IsAuthenticated,)
def get(self, request):
material = Material.objects.all()
serializer = MaterialSerializer(material, many=True)
return JsonResponse(serializer.data, safe=False)
def post(self, request):
serializer = MaterialSerializer(data=request.data)
if serializer.is_valid():
serializer.save()
return JsonResponse(serializer.data, status=201)
return JsonResponse(serializer.errors, status=400)
class WorkshopListView(APIView):
#permission_classes = (IsAuthenticated,)
def get(self, request):
### TESTED MATERIALS FOR DIFFERENT WORKSHOPS
#workshop = WorkshopMaterials.objects.prefetch_related(Prefetch('workshop', queryset=Workshop.objects.filter(id=3)))
#serializer = WorkshopMaterialsSerializer(workshop, many=True)
### WORKING FOR LIST VIEW (NO DETAILS)
#workshops = Workshop.objects.prefetch_related('workshop').all()
#serializer = WorkshopSerializer(workshops, many=True, fields=('id', 'leader', 'title', 'categorie', 'language'))
### NOW TRY TO GET A FULL LIST WITH ALL WORKSHOP FIELDS AND ALL MATERIAL FOR THOSE
### CURRENTLY FAILING HERE.
workshops = Workshop.objects.prefetch_related('workshop').all()
serializer = WorkshopSerializer(workshops, many=True)
return JsonResponse(serializer.data, safe=False)
def post(self, request):
return JsonResponse({'detail': 'WIP'}, status=400)
My current output in JSON Format:
[{
"id": 3,
"title": "SPECIAL TITLE",
"description": "SOME TEXT FOR DESC",
"categorie": "OTH",
"language": "EN",
"duration": "1H",
"needs_tables": true,
"participants": "XS",
"custom_participants": 1,
"daytime": "ANYT",
"repeats": "NOREPEAT",
"location": "BACKLOG",
"own_material": "",
"additional_infos": "",
"costs_currency": "EUR",
"costs": "0.00",
"cost_description": "",
"leader": "COOL LEADER"
}]
My wanted output in JSON Format:
[{
"id": 3,
"title": "SPECIAL TITLE",
"description": "SOME TEXT FOR DESC",
"categorie": "OTH",
"language": "EN",
"duration": "1H",
"needs_tables": true,
"participants": "XS",
"custom_participants": 1,
"daytime": "ANYT",
"repeats": "NOREPEAT",
"location": "BACKLOG",
"own_material": "",
"additional_infos": "",
"costs_currency": "EUR",
"costs": "0.00",
"cost_description": "",
"leader": "COOL LEADER",
"material": [
{
id: 1,
name: "Material 1",
},
{
id: 2,
name: "Material 2",
},
{
id: 3,
name: "Material 3",
}
}
}]
How can i use my WorkshopMaterialsSerializer to work with my WorkshopSerializer to get my the output i want? And how can i handle it on the performance side? Currently i tried to Prefetch
You can get that json structure like this.
You just need to query all the materials from the WorkshopMaterials modal in the get_material SerializerMethodField method and then pass that to a slightly updated WorkhopMaterialSerializer
You can leave your old MaterialSerializer untouched, since its being used by another view.
class WorkhopMaterialSerializer(serializers.ModelSerializer):
id = serializers.IntegerField(source='material.id')
name = serializers.CharField(source='material.name')
class Meta:
model = WorkshopMaterials
fields = ('id', 'name')
extra_kwargs = {'id': {'read_only': True}}
class WorkshopSerializer(serializers.ModelSerializer):
material = serializers.SerializerMethodField()
class Meta:
model = Workshop
exclude = ['created_at', 'updated_at']
def __init__(self, *args, **kwargs):
fields = kwargs.pop('fields', None)
super().__init__(*args, **kwargs)
if fields is not None:
allowed = set(fields)
existing = set(self.fields)
for field_name in existing - allowed:
self.fields.pop(field_name)
def to_representation(self, instance):
rep = super().to_representation(instance)
workshopLeaderData = WorkshopLeaderSerializer(instance.leader).data
workshopLeaderName = workshopLeaderData["name"]
if workshopLeaderData["displayname"] == "AN":
workshopLeaderName = workshopLeaderData["artistname"]
rep["leader"] = workshopLeaderName
return rep
def get_material(self, instance):
workshop_materials = WorkshopMaterials.objects.filter(workshop_id=instance.id)
return WorkhopMaterialSerializer(workshop_materials, many=True).data
Add the required imports, etc and I am assuming this is how your fields are for Material model.
material.id and material.name