I am attempting to set up a nested serializer in Django REST Framework, but after following the short guide in the documentation, http://www.django-rest-framework.org/api-guide/relations/#nested-relationships, I have had no change in the serialized data.
models.py
class Franchise(models.Model):
id = models.AutoField(primary_key=True)
name = models.CharField(max_length=255)
class Item(models.Model):
id = models.AutoField(primary_key=True)
franchise = models.ForeignKey(Franchise, on_delete=None)
title = models.CharField(max_length=255)
Initial serializers.py
class ItemListSerializer(serializers.ModelSerializer):
class Meta:
model = Item
fields = ('id', 'franchise', 'title')
class FranshiseDetailSerializer(serializers.ModelSerializer):
class Meta:
model = Franchise
fields = ('id', 'name', 'items')
When I query ItemListSerializer with a query set I get back the expected:
[
{
"id": 1,
"franchise": 1,
"title": "Item 1",
},
{
"id": 2,
"franchise": 1,
"title": "Item 2"
},
{
"id": 3,
"franchise": 2,
"title": "Item 3",
}
]
And the expected result when I query FranchiseDetailSerializer with a pre-existing franchise object.
{
"id": 1,
"name": "Franchise 1"
}
Now, when I change FranchiseDetailSerializer, as per the DRF guide on nested relations:
class FranshiseDetailSerializer(serializers.ModelSerializer):
items = ItemListSerializer(many=True, read_only=True)
class Meta:
model = Franchise
fields = ('id', 'name', 'items')
I would expect the get the following result:
{
"id": 1,
"name": "Franchise 1"
"items": [
{"id": 1, "title": "Item 1", "franchise": 1},
{"id": 2, "title": "Item 2", "franchise": 1}
]
}
But instead, I get no change, as though I hadn't updated FranchiseDetailSerializer at all:
{
"id": 1,
"name": "Franchise 1"
}
The worst part about this for me is that I am not getting any kind of error, I'm simply not seeing results.
Any and all help is appreciated, thanks.
Actually you missed a tiny part of docs :)
album = models.ForeignKey(Album, related_name='tracks')
Define related_name in ForeignKey
franchise = models.ForeignKey(Franchise, on_delete=None, related_name='items')
After that stuff started working for me.
Related
I have two models List and Card. I'm trying to combine these two and make a single JSON response
My List JSON response
[
{
"id": 1,
"name": "List of things to do"
},
{
"id": 2,
"name": "one more"
}
]
My Card JSON response
[
{
"id": 1,
"title": "My first scrum card",
"description": "list things todo here",
"story_points": null,
"business_value": null,
"list": 1
},
{
"id": 2,
"title": "File my taxes",
"description": "fill it before 1st of nov",
"story_points": null,
"business_value": null,
"list": 1
},
]
My serializers.py file
from rest_framework import serializers
from .models import List, Card
class CardSerializer(serializers.ModelSerializer):
class Meta:
model = Card
fields = '__all__'
class ListSerializer(serializers.ModelSerializer):
cards = CardSerializer(read_only=True, many=True)
class Meta:
model = List
fields ='__all__'
My api.py file
from rest_framework.viewsets import ModelViewSet
from .models import List, Card
from .serializers import ListSerializer, CardSerializer
class ListViewSet(ModelViewSet):
queryset = List.objects.all()
serializer_class = ListSerializer
class CardViewSet(ModelViewSet):
queryset = Card.objects.all()
serializer_class = CardSerializer
My models.py
from django.db import models
class List(models.Model):
name = models.CharField(max_length=50)
def __str__(self):
return "List : {}".format(self.name)
class Card(models.Model): # to create card table
title = models.CharField(max_length=100)
description = models.TextField(blank=True)
list = models.ForeignKey(List, related_name = "card"
,on_delete=models.PROTECT) # creating a foriegn key for storing list
story_points = models.IntegerField(null=True, blank = True)
business_value = models.IntegerField(null=True, blank = True)
def __str__(self):
return "Card : {}".format(self.title)
How can I achieve something like below in My List JSON response ?
[
{
"id": 1,
"cards":[
{
"id": 1,
"title": "My first scrum card",
"description": "list things todo here",
"story_points": null,
"business_value": null,
"list": 1
}],
"name": "List of things to do"
},
{
"id": 2,
"cards":[
{
"id": 2,
"title": "File my taxes",
"description": "fill it before 1st of nov",
"story_points": null,
"business_value": null,
"list": 1
}],
"name": "one more"
},
]
I have tried to do it but I was unable to implement it. So I posted it here.
Heading
Many thanks.
You can also use SerializerMethodeField https://www.django-rest-framework.org/api-guide/fields/#serializermethodfield.
class ListSerializer(serializers.ModelSerializer):
cards = serializers.SerializerMethodField()
class Meta:
model = List
fields = '__all__'
def get_cards(self, obj):
data = CardSerializer(obj.card.all(), many=True).data
return data
change the list related_name to cards and ListViewSet will do what you want
class Card(models.Model): # to create card table
title = models.CharField(max_length=100)
description = models.TextField(blank=True)
list = models.ForeignKey(List, related_name = "cards"
,on_delete=models.PROTECT)
...
I'm working on building a tree-like hierarchical database system using Django Rest Framework and django-polymorphic-tree. I have two models- BaseTreeNode and DescriptionNode (the later one is derived from BaseTreeNode). Specifically, here's my models.py:
class BaseTreeNode(PolymorphicMPTTModel):
parent = PolymorphicTreeForeignKey('self', blank=True, null=True, related_name='children', verbose_name=_('parent'))
title = models.CharField(_("Title"), max_length=200)
def __str__(self):
return "{}>{}".format(self.parent, self.title)
class Meta(PolymorphicMPTTModel.Meta):
verbose_name = _("Tree node")
verbose_name_plural = _("Tree nodes")
# Derived model for the tree node:
class DescriptionNode(BaseTreeNode):
description = models.CharField(_("Description"), max_length=200)
class Meta:
verbose_name = _("Description node")
verbose_name_plural = _("Description nodes")
So, each title field (belonging to BaseTreeNode) has an associated description field (belonging to DescriptionNode) with it.
Now, all I want to have is a JSON that returns a nested representation of my entire tree.
For now, I have only defined a simple serializer with a recursive field.
My serializers.py
from rest_framework_recursive.fields import RecursiveField
class DescriptionNodeSerializer(serializers.ModelSerializer):
class Meta:
model = DescriptionNode
fields = ('description',)
class BaseTreeNodeSerializer(serializers.ModelSerializer):
subcategories = serializers.ListSerializer(source="children",child=RecursiveField())
class Meta:
model = BaseTreeNode
fields = ('id', 'title', 'subcategories')
Which gives me (for BaseTreeNodeSerializer only):
[
{
"id": 1,
"title": "Apple",
"subcategories": [
{
"id": 2,
"title": "Contact Person",
"subcategories": []
},
{
"id": 3,
"title": "Sales Stage",
"subcategories": [
{
"id": 4,
"title": "Suspecting",
"subcategories": [
{
"id": 5,
"title": "Contact verification",
"subcategories": []
}
]
},
{
"id": 6,
"title": "Prospecting",
"subcategories": [
{
"id": 7,
"title": "Client Detail",
"subcategories": []
}
]
}
]
},
{
"id": 9,
"title": "Medium",
"subcategories": [
{
"id": 10,
"title": "Status",
"subcategories": []
}
]
},
{
"id": 13,
"title": "Remainder",
"subcategories": []
}
]
}
]
My question is, how can I include the description field (from the derived model) which is associated with every single title field (from the BaseTreeNode model) in the hierarchy?
Something like:
... {
"id": 5,
"title": "Contact verification",
"description": "Verified"
"subcategories": []
} ...
The Corresponding Model would be as follows:
class DescriptionNode(BaseTreeNode):
basetreenode = models.OneToOneField(BaseTreeNode, related_name="base_tree")
description = models.CharField(_("Description"), max_length=200)
class Meta:
verbose_name = _("Description node")
verbose_name_plural = _("Description nodes")
Serializer would be as follows:
from rest_framework_recursive.fields import RecursiveField
class BaseTreeNodeSerializer(serializers.ModelSerializer):
description = serializers.SerializerMethodField()
subcategories = serializers.ListSerializer(source="children",child=RecursiveField())
class Meta:
model = BaseTreeNode
fields = ('id', 'title', 'description', 'subcategories')
def get_description(self, obj):
return obj.base_tree.description #base_tree is related name of basetreenode field
I have a working API in my project that look something like this :
{
"id": 1,
"project_name": "Project A",
"user": [
{
"id": 3,
"employee_id": "001",
"official_name": "RAY PAlMER",
"nick_name": "RAY",
"date_of_birth": "1965-08-25",
"gender": "1",
"race": "CAUCASIAN",
"food_pref": "Vegetarian",
},
{
"id": 3,
"employee_id": "002",
"official_name": "LAIRA OMOTO",
"nick_name": "LAIRA",
"date_of_birth": "1990-01-15",
"gender": "2",
"race": "WHITE",
"food_pref": "Any",
}
]
}
The user field is a foreign key field and its populating everything from its source model called Employee. My question is how can I populate the user many to many field with only several field that I wanted to get from the Employee Model. For example I just want to populate only a user id, official name, and gender, therefore the output should be something like this
{
"id": 1,
"project_name": "Project A",
"user": [
{
"id": 3,
"official_name": "RAY PAlMER",
"gender": "1",
},
{
"id": 4,
"official_name": "LAIRA",
"gender": "2",
}
]
}
Below is my source code :
Project Model :
class Project(models.Model):
user = models.ManyToManyField(Employee, blank=True)
Employee Model :
class Employee(models.Model):
official_name = models.CharField(max_length=200, null=True, blank=True)
gender_choice = (
('male', 'Male'),
('female', 'Female')
)
gender = models.CharField(max_length=10, choices=gender_choice, null=True,
blank=True)
Serializer :
class MarketingReportSerializer(serializers.ModelSerializer):
class Meta:
model = Project
fields = ('id', 'project_name','user')
depth = 1
Any help is much appreciated thanks!
API :
class MarketingReportAPI(APIView):
def get(self, request):
all_projects = Project.objects.all()
project_serializer = MarketingReportSerializer(all_projects, many=True)
return Response(project_serializer.data)
Create EmployeeSerializer serializer.
class EmployeeSerializer(serializers.ModelSerializer):
class Meta:
model = Employee
fields = ('id', 'official_name', 'gender')
Now use it in your MarketingReportSerializer
class MarketingReportSerializer(serializers.ModelSerializer):
user = EmployeeSerializer(many=True)
class Meta:
model = Project
fields = ('id', 'project_name', 'user')
And then you can use MarketingReportSerializer in your view.
I have model Product:
class Product(TranslatableModel):
name = models.CharField(max_length=255, unique=True)
translations = TranslatedFields(
description=models.TextField(),
)
and in administration on product detail I have tabs with languages. For example tabs EN, CZ, each includes disctiption. So PUT request looks like:
{
'product': '1',
'id': 1,
'name': 'Name',
'translations': {
'cz': {'desctiption': 'Description cz'},
'en': {'desctiption': 'Description en'}
}
}
I founded in django-hvad TranslationsMixin that allows me to do that request.
in serializers I have:
class ProductTranslationSerializer(serializers.ModelSerializer):
class Meta:
exclude = ['description']
class ProductSerializer(TranslationsMixin, serializers.ModelSerializer):
class Meta:
model = Product
translations_serializer = ProductTranslationSerializer
fields = (
'name',
'description',
)
Question is how will looks ModelViewSet for this request? Can I choose language like 'language_code=en', filter that query and get something like:
[
{
id: 1
name: "name"
descritpion: "descritpion"
},
....
]
Thank you!
the most likely way i achieve is:
models.py
class Product(TranslatableModel):
category = models.ForeignKey('product.ProductCategory',
related_name='product_category',
null=True,
on_delete=models.SET_NULL,
verbose_name=u'category')
cover = models.ImageField(upload_to=product_cover,
null=True,
verbose_name=u'cover')
translations = TranslatedFields(
title=models.CharField(max_length=100,
null=True,
verbose_name=u'title'),
summary=models.TextField(null=True,
verbose_name=u'summary'),
model=models.CharField(max_length=255,
null=True,
blank=True,
verbose_name=u'model'),
price=models.DecimalField(default=0.00,
max_digits=10,
decimal_places=2,
blank=True,
validators=[MinValueValidator(0)],
verbose_name=u'price'),
content=models.TextField(verbose_name=u'content'),
publish_time=models.DateTimeField(default=timezone.now,
verbose_name=u'发布publish_time')
)
view_times = models.IntegerField(default=0,
verbose_name=u'view_times ')
views.py
class ProductViewSet(ModelViewSet):
serializer_class = ProductListSerializer
def get_queryset(self):
if 'language_code' in self.request.GET:
language_code = self.request.GET.get('language_code')
queryset = Product.objects.language(language_code).order_by('-id')
else:
queryset = Product.objects.language().order_by('-id')
return queryset
serializers.py
class ProductCategorySerializer(TranslatableModelSerializer):
class Meta:
model = ProductCategory
fields = '__all__'
class ProductListSerializer(TranslatableModelSerializer):
category = ProductCategorySerializer(read_only=True)
class Meta:
model = Product
exclude = ['is_abandon', 'content', ]
urls.py
from rest_framework import routers
router = routers.DefaultRouter()
router.register(r'product', ProductViewSet, base_name='api-product')
...
result:
http://192.168.1.108/api/product/?language_code=zh-hans you get:
{
"count": 1,
"page_num": 1,
"page_no": 1,
"next": "",
"previous": "",
"results": [
{
"id": 2,
"category": {
"id": 2,
"create_time": "2017-08-10 16:49:41",
"update_time": "2017-08-18 08:56:02",
"name": "测试",
"language_code": "zh-hans"
},
"create_time": "2017-08-18 08:53:46",
"update_time": "2017-08-18 08:56:28",
"cover": "http://192.168.1.108/media/product/20170818-085346-518_59.jpg",
"view_times": 0,
"title": "标题",
"summary": "简介",
"model": null,
"price": "90.00",
"publish_time": "2017-08-18 08:53:00",
"language_code": "zh-hans"
}
]
}
http://192.168.1.108/api/product/?language_code=en you get:
{
"count": 1,
"page_num": 1,
"page_no": 1,
"next": "",
"previous": "",
"results": [
{
"id": 2,
"category": {
"id": 2,
"create_time": "2017-08-10 16:49:41",
"update_time": "2017-08-18 08:56:02",
"name": "测试",
"language_code": "zh-hans"
},
"create_time": "2017-08-18 08:53:46",
"update_time": "2017-08-18 09:00:23",
"cover": "http://192.168.1.108/media/product/20170818-085346-518_59.jpg",
"view_times": 0,
"title": "title",
"summary": "summary",
"model": "model",
"price": "91.00",
"publish_time": "2017-08-18 08:56:04",
"language_code": "en"
}
]
}
this way fk will not change language,if you want fk change language too,use:
urls.py
urlpatterns += i18n_patterns(
'''
url(r'^api/', include(router.urls)),
prefix_default_language=False,
)
change language by
http://192.168.1.108/zh-hans/api/product/
to
http://192.168.1.108/en/api/product/
your will get:
{
"count": 1,
"page_num": 1,
"page_no": 1,
"next": "",
"previous": "",
"results": [
{
"id": 2,
"category": {
"id": 2,
"create_time": "2017-08-10 16:49:41",
"update_time": "2017-08-18 08:56:02",
"name": "test",
"language_code": "en"
},
"create_time": "2017-08-18 08:53:46",
"update_time": "2017-08-18 09:00:23",
"cover": "http://192.168.1.108/media/product/20170818-085346-518_59.jpg",
"view_times": 0,
"title": "title",
"summary": "summary",
"model": "model",
"price": "91.00",
"publish_time": "2017-08-18 08:56:04",
"language_code": "en"
}
]
}
Answer from owner of django-hvad github repo #spectras:
If I understand well, you want to use a different serialized form for the collection endpoint and the item endpoint. That is, GET-1, PUT, POST would use the translations mixin, while GET-many would not.
You need two have two different serializers for this:
The one you created
another one that would be, for instance,
class ProductItemSerializer(TranslatableModelSerializer): ...
another one that would be, for instance,
class ProductItemSerializer(TranslatableModelSerializer): ...
Given that, you can add to your ModelViewSet a method that dynamically chooses the serializer class depending on request type:
class SomeModelViewSet(ModelViewSet):
# serializer_class = not needed, we use the method instead
def get_serializer_class(self):
if self.action == 'list':
return ProductItemSerializer
return ProductSerializer
An alternate method, perhaps easier to use on the Javascript side, would be to make 2 viewsets for the Product model, a read-write one being translation aware (using ProductSerializer) and a read-only one not translation aware, using (ProductItemSerializer).
In the same vein, I usually only have translation-unaware serializers and add a /api/product/details/ endpoint that is translation-aware. This way, I only have to handle the complexity of a dict object when going into edit/detailed mode on the client side.
I've two models (Map and Place) and I want to create a JSON with both of these (a map contains several places).
models.py
class Map(models.Model):
name = models.CharField(max_length=100)
slug = models.SlugField(max_length=200)
class Place(models.Model):
map = models.ForeignKey('main.Map')
name = models.CharField(max_length=100)
slug = models.SlugField(max_length=200)
I use this to serialize these models individually :
serializers.py
class MapSerializer(serializers.ModelSerializer):
class Meta:
model = Map
fields = ('id', 'name')
class PlaceSerializer(serializers.ModelSerializer):
class Meta:
model = Place
fields = ('id', 'name', 'map')
I want a JSON like this, but I've no idea how to serialize this correctly...
{
"maplist": {
"maps": [
{
"id": "1",
"name": "dust2",
"places": [
{
"id": "1",
"name": "Long"
},
{
"id": "2",
"name": "Middle"
}
]
},
{
"id": "2",
"name": "inferno",
"places": [
{
"id": "1",
"name": "Middle"
},
{
"id": "2",
"name": "ASite"
}
]
}
]
}
}
Thanks in advance for your help.
Try with nested serializers:
class PlaceSerializer(serializers.ModelSerializer):
class Meta:
model = Place
fields = ('id', 'name')
class MapSerializer(serializers.ModelSerializer):
places = PlaceSerializer(many=True)
class Meta:
model = Map
fields = ('id', 'name')
To make this work, you need to change your model to include a related name to your foreign key:
class Place(models.Model):
map = models.ForeignKey('main.Map', related_name="places")
name = models.CharField(max_length=100)
slug = models.SlugField(max_length=200)