Customize the nested data in Serializer - python

I have a ModelSerializer:
class WorkOrderRetrieveSerializer(ModelSerializer):
workordercomments = WorkOrderCommentForWorkOrderSerializer(many=True, read_only=True)
class Meta:
model = WorkOrder
fields = "__all__"
The JSON data is bellow:
{
"id": 1,
"workordercomments": [
.....
{
"id": 21,
"content": "test files",
"files": "[71]",
"ctime": "2018-01-11T11:03:17.874268+08:00",
"uptime": "2018-01-11T11:03:17.874362+08:00",
"workorder": 1,
"comment_user": {
"id": 5,
"username": "test03",
"is_admin": true
}
}
],
"workorder_num": "WON15118747168252",
"name": "order01",
"content": "first conntetn",
"workordertype": "teck",
"workorder_status": "created",
"user_most_use_email": "lxas#128.com",
"server_id": null,
"public_ip": null,
"belong_area": null,
"files": null,
"ctime": "2017-11-28T21:11:56.826971+08:00",
"uptime": "2017-11-28T21:11:56.827064+08:00",
"to_group": 3,
"user": 2
}
The "files": "[71]", in my JSON is a string of a group contains file ids.
workordercomments is the related-name of the workorder.
I want in the JSON workordercomments shows the files like this:
{
"id": 21,
"content": "test files",
"files": "['/media/images/xxxxx.png']",
"ctime": "2018-01-11T11:03:17.874268+08:00",
"uptime": "2018-01-11T11:03:17.874362+08:00",
"workorder": 1,
"comment_user": {
"id": 5,
"username": "test03",
"is_admin": true
}
}
The "files" value I want to is the link rather than its id.
"files": "['/media/images/xxxxx.png']",
or
"files": ['/media/images/xxxxx.png'],
Is it possible to customize the format? should I come true what function in serializer ?

You need to implement a custom serialzier, as per the docs, and override the default values generated by ModelSerializer.
For example:
from rest_framework.fields import Field
class FileRelatedField(RelatedField):
def to_representation(self, instance):
return instance.file_path # or whereever that path comes from
class WorkOrderRetrieveSerializer(ModelSerializer):
class Meta:
model = WorkOrder
fields = '__all__'
files = FileRelatedField(
many=True,
source='file_set.all'
)
Depending on how your __str__ value is on your File model, you can maybe do this:
from rest_framework.serializers import StringRelatedField
class WorkOrderRetrieveSerializer(ModelSerializer):
class Meta:
model = WorkOrder
fields = '__all__'
files = StringRelatedField(
many=True,
source='file_set.all'
)

Related

Django Restframework with nested json and custom key

Iam using Django with Restframework.
Iam trying to get a json output from serializers in a nested manner with key as one of the fields from model. I acheived the nested JSON but the json key for them is troubling me.
Here is my code and expected results out of it:
Models.py
class Tags(models.Model):
tagId = models.CharField(primary_key=True, max_length=100, default=1)
section = models.CharField(max_length=100,default=1)
def __str__(self):
return self.section
class TagItem(models.Model):
section= models.ForeignKey(Tags, on_delete=models.CASCADE,default=1,related_name="items")
select = models.BooleanField(default=False)
name = models.CharField(max_length=50)
def __str__(self):
return self.name
serializers.py
class TagItemModelSerializer(serializers.ModelSerializer):
class Meta:
model = TagItem
fields = '__all__'
class TagModelSerializer(serializers.ModelSerializer):
items = TagItemModelSerializer(many=True)
class Meta:
model = Tags
fields = ['pk','section', 'items']
Expected output:
{
"crafts" : { //craft is comming from Tag model's "section"
"id": 1,
"section": "crafts",
"items": [
{
"id": "10",
"select": false,
"name": "Wood",
"category": "crafts"
},
]
},
"states" : {
"id": 2,
"section": "states",
"items": [
{
"id": "20",
"select": false,
"name": "Andhra Pradesh",
"category": "states"
}
]
},
"others" : {
"id": 3,
"section": "others",
"items": [
{
"id": "30",
"select": false,
"name": "Volunteer",
"category": "others"
}
]
}
}
Current output:
[ //cant get the key of Tag model's "section"
{
"pk": "1",
"section": "states",
"items": [
{
"id": 6,
"select": false,
"name": "Assam",
"section": "1"
}
]
},
{
"pk": "2",
"section": "others",
"items": [
{
"id": 12,
"select": false,
"name": "Artisan",
"section": "2"
}
]
},
{
"pk": "3",
"section": "crafts",
"items": [
{
"id": 9,
"select": false,
"name": "Metal",
"section": "3"
}
]
}
]
At your case, you would like to have a custom representation I think?
You can adjust it with overriding to_representation()
I provide two approaches:
serializer -> the better way but not quite the output you prefer
view
class TagModelView(views.APIView):
def get(self, request):
qs = Tags.objects.all()
serializer = TagModelSerializer(qs, many=True)
return Response(data=serializer.data)
serializer
class TagItemModelSerializer(serializers.ModelSerializer):
category = serializers.SerializerMethodField()
class Meta:
model = TagItem
fields = ['id', 'select', 'name', 'category']
def get_category(self, instance):
return instance.section.section
class TagModelSerializer(serializers.ModelSerializer):
items = TagItemModelSerializer(many=True)
class Meta:
model = Tags
fields = ['pk', 'section', 'items']
def to_representation(self, instance):
container = super().to_representation(instance)
return {container.get('section'): container}
Making representation in your view -> output you would like to get
view
def get(self, request):
qs = Tags.objects.all()
serializer = TagModelSerializer(qs, many=True)
container = dict()
for element in serializer.data:
container.update(**element)
return Response(data=container)
serializer
No change to my proposal obove.
update
I saw that your primary key of Tags is tagId and you are using fields = ['pk', 'section', 'items'] but you would like to have id as a key-name.
Relabeling can help you.
class TagModelSerializer(serializers.ModelSerializer):
items = TagItemModelSerializer(many=True)
id = serializers.CharField(source='tagId')
class Meta:
model = Tags
fields = ['id', 'section', 'items']

Django Model Serializers

I'm learning how to use Django Rest Framework and I came out with a question that I can't get to answer.
I understood that the concept of nested serializer but I think there should be a way to get a specific field in an "upper level" instead of "digging" trough levels. Let me better explain what I mean.
I have Users which then are classified into 2 categories Customers (which are the default User category) and Drivers. All the Users have a Profile with their picture so I would like to obtain the name and the image in an API. The only solution I've been managing to find is the following
class OrderProfileSerializer(serializers.ModelSerializer):
class Meta:
model = Profile
fields = ("id", "image")
class OrderUserSerializer(serializers.ModelSerializer):
profile = OrderProfileSerializer()
class Meta:
model = User
fields = ("id", "profile")
class OrderCustomerSerializer(serializers.ModelSerializer):
name = serializers.ReadOnlyField(source="get_full_name")
profile = OrderProfileSerializer()
class Meta:
model = User
fields = ("id", "name", "profile")
class OrderDriverSerializer(serializers.ModelSerializer):
name = serializers.ReadOnlyField(source="user.get_full_name")
user = OrderUserSerializer()
class Meta:
model = Driver
fields = ("id", "name", "user")
This is the JSON response
{
"shipping": {
"id": 25,
"customer": {
"id": 14,
"name": "Test Customer",
"profile": {
"id": 10,
"image": "/media/profile_pics/default.jpg"
}
},
"driver": {
"id": 1,
"name": "Test Driver",
"user": {
"id": 28,
"profile": {
"id": 11,
"image": "/media/profile_pics/default.jpg"
}
}
}
}
}
I can make it to work anyway, but I believe that to learn I should always push for a more "elegant" solution rather than "keep the easiest". So I would like to achieve the following response:
{
"shipping": {
"id": 25,
"customer": {
"id": 14,
"name": "Test Customer",
"image": "/media/profile_pics/default.jpg"
},
"driver": {
"id": 1,
"name": "Test Driver",
"image": "/media/profile_pics/default.jpg"
}
}
}
Thank you for any tips/help/suggest that you can provide
Instead of using:
profile = OrderProfileSerializer()
re-write to:
image = serializers.SerializerMethodField()
def get_image(self, obj):
# obj is the customer object
# return what u need (like this example) or write a model inner method
return obj.profile.image
This would align nicely to the json you want
Do the same thing for Driver and User

how to access child entire record in parent model in django rest framework

I am new to Django rest framework.i am trying to get child model records to the parent model as a field so that all the RefreshmentImage models records are available in games_sports list.i have posted sample code.
model.py
class Refreshment(models.Model):
title = models.CharField(max_length=200, unique=True)
type = models.CharField(max_length=200)
charges = models.DecimalField(max_digits=12, decimal_places=2, help_text="Charges per hour")
class RefreshmentImage(models.Model):
refreshment = models.ForeignKey(Refreshment, on_delete=models.CASCADE)
image = models.FileField(upload_to="refreshment_image/", null=True, blank=True)
serializers.py
class EntertainmentSerializer(serializers.ModelSerializer):
class Meta:
model = Refreshment
fields = '__all__'
class RefreshmentImageSerializer(serializers.ModelSerializer):
refreshment = EntertainmentSerializer(read_only=True, many=True)
class Meta:
model = RefreshmentImage
fields = '__all__'
views.py
def all_games_sports(request):
entertainment = Refreshment.objects.all()
serialize = EntertainmentSerializer(instance=entertainment,many=True)
serial = RefreshmentImageSerializer(instance=entertainment,many=True)
main = {'status': True, 'code': CODE_SUCCESSFUL, 'msg': SUCCESS, 'games_sports': serialize.data,'image':serial.data}
return HttpResponse(json.dumps(main), content_type='application/json')
what i got is like:
games_sports": [
{
"id": 1,
"title": "yyy",
"type": 1,
"charges": "500.00",
},
{
"id": 2,
"title": "xxxxx",
"type": "something",
"charges": "501.00",
}
*******
],
"image": [
{
"id": 1,
"image": null,
"date_created": "2019-03-03T08:16:15.538024+05:30"
},
**********
]
i want it to be:
games_sports": [
{
"id": 1,
"title": "yyy",
"type": 1,
"charges": "500.00",
"image": [
{
"id": 1,
"image": image_path,
"date_created": "2019-03-03T08:16:15.538024+05:30"
},
}
***********
],
Try this snippet
#serializers.py
"""I've re-arranged the order of 'RefreshmentImageSerializer' serializer and 'EntertainmentSerializer' serializer"""
class RefreshmentImageSerializer(serializers.ModelSerializer):
class Meta:
model = RefreshmentImage
fields = '__all__'
class EntertainmentSerializer(serializers.ModelSerializer):
image = RefreshmentImageSerializer(many=True, source='refreshmentimage_set')
class Meta:
model = Refreshment
fields = '__all__'
# views.py
"""Added DRF stuffs such as 'api_view' and 'Response'"""
from rest_framework.decorators import api_view
#api_view()
def all_games_sports(request):
entertainment = Refreshment.objects.all()
serialize = EntertainmentSerializer(instance=entertainment, many=True)
main = {'status': True, 'code': "CODE_SUCCESSFUL", 'msg': "SUCCESS", 'games_sports': serialize.data}
return Response(main)
{
"status": true,
"code": "CODE_SUCCESSFUL",
"msg": "SUCCESS",
"games_sports": [
{
"id": 1,
"image": [
{
"id": 1,
"image": null,
"refreshment": 1
},
{
"id": 3,
"image": "refreshment_image/jpg-icon.png",
"refreshment": 1
}
],
"title": "t1",
"type": "tt1",
"charges": "123.00"
},
{
"id": 2,
"image": [
{
"id": 2,
"image": "refreshment_image/asd.jpg",
"refreshment": 2
}
],
"title": "t2",
"type": "tt2",
"charges": "321.00"
},
{
"id": 3,
"image": [
{
"id": 4,
"image": "refreshment_image/Screenshot_from_2018-10-26_16-32-41.png",
"refreshment": 3
},
{
"id": 5,
"image": "refreshment_image/twitter.png",
"refreshment": 3
}
],
"title": "t3",
"type": "tt3",
"charges": "754.00"
}
]
}
What I've done here?
re-arranged the order of serializer to avoid not defined errors
added a new field in EntertainmentSerializer class to show the images associated with the Refreshment object
In views.py I've added DRF pieces of stuff, which is more suitable
References
#api_view() decorator
DRF's Response() class
DRF Nested Serializers
The source keyword argument
Hope this helps!!

Django REST: Passing extra fields from connected models

I need to add additional fields that are not part of my model to the json response. Is this possible? The models are connected using multiple tables, but do not have a direct connection.
models.py
class Message(models.Model):
body = models.TextField(max_length=500, blank=False)
sender = models.ForeignKey(User)
timestamp = models.DateTimeField(auto_now_add=True)
conversation = models.ForeignKey(Conversation)
serializers.py
class MessageSerializer(serializers.ModelSerializer):
conversation = serializers.ReadOnlyField(source='conversation.id')
sender = serializers.ReadOnlyField(source='sender.id')
# task = TaskSerializer(source='conversation__task_worker__task.id')
# This commented code above is not working, but this is what I need.
class Meta:
model = Message
fields = '__all__'
So what I need, is to pass the value of task, which can be found by going back a few tables. E.g. if the current model is Message, I need to:
Message -> Conversation -> Task_worker -> Task (Get this)
My current json response is:
{
"count": 2,
"next": null,
"previous": null,
"results": [
{
"id": 1,
"conversation": 1,
"sender": 2,
"body": "Hello There",
"timestamp": "2018-01-31T17:48:19.680113Z"
},
{
"id": 3,
"conversation": 1,
"sender": 2,
"body": "Can you do the task",
"timestamp": "2018-02-01T09:39:24.797218Z"
}
]
}
Ideally, I would like the following response:
{
"count": 2,
"next": null,
"previous": null,
"conversation": 1,
"task": 5,
"any_extra_fields_key": 'value',
"results": [
{
"id": 1,
"sender": 2,
"body": "Hello There",
"timestamp": "2018-01-31T17:48:19.680113Z"
},
]
}
The response is after (list view): GET /api/conversations/<conversation-id>/messages/
EDIT: added views.py
class MessageList(generics.ListCreateAPIView):
serializer_class = MessageSerializer
def get_queryset(self):
conversation = Conversation.objects.get(pk=self.kwargs['conv_id'])
queryset = Message.objects.filter(conversation=conversation)
return queryset
def perform_create(self, serializer):
conversation = Conversation.objects.get(pk=self.kwargs['conv_id'])
serializer.save(sender=self.request.user, conversation=conversation)
EDIT 2:
class MessageSerializer(serializers.ModelSerializer):
sender = serializers.ReadOnlyField(source='sender.id')
children_list = serializers.SerializerMethodField('get_children')
def get_children(self, obj):
serializer = TaskSerializer(source='conversation__task_worker__task', many=True)
return serializer.data
class Meta:
model = Message
fields = ['children_list','sender','conversation','timestamp']
outputs:
{
"count": 2,
"next": null,
"previous": null,
"results": [
{
"children_list": [],
"sender": 2,
"conversation": 1,
"timestamp": "2018-01-31T17:48:19.680113Z"
},
{
"children_list": [],
"sender": 2,
"conversation": 1,
"timestamp": "2018-02-01T09:39:24.797218Z"
}
]
}
First of all, children list is empty, but it should be the task, and also it's still inside the 'results' key, creating a lot of duplication, since the children_list is the same task.
SerializerMethodField is what I needed to get me the data that I want. However, the structure is still a problem
class MessageSerializer(serializers.ModelSerializer):
sender = serializers.ReadOnlyField(source='sender.id')
task_id = serializers.SerializerMethodField()
def get_task_id(self, obj):
task = Task.objects.filter(task_worker__conversation__message=obj)[0]
return task.id
class Meta:
model = Message
fields = ['task_id','sender','conversation','timestamp']

How to sort serialized fields with Django Rest Framework

I'm looking for suggestions on how to sort/group serialized fields by value.
Here's a code example explaining what I want to achieve.
Models
class Folder(models.Model):
name = models.CharField()
class File(models.Model):
filetype = models.CharField()
name = models.CharField()
folder = models.ForeignKey(Folder)
Serializers
class FileSerializer(serializers.ModelSerializer):
class Meta:
model = File
fields = ('id', 'filetype', 'name')
class FolderSerializer(serializers.ModelSerializer):
files = FileSerializer(read_only=True)
class Meta:
model = Folder
fields = ('name', 'files')
This serializes to:
{
"name": "Test Folder",
"files": [
{"id": 1, "filetype": "pdf", "name": "some pdf file"}.
{"id": 2, "filetype": "pdf", "name": "some other pdf file"},
{"id": 3, "filetype": "txt", "name": "some text file"}
]
}
I'm looking for a way to serialize to this:
{
"name": "Test Folder",
"files": [
"pdf": [
{"id": 1, "name": "some pdf file"},
{"id": 2, "name": "some other pdf file"}
],
"txt": [
{"id": 3, "name": "some text file"}
]
]
}
Try to use SerializerMethodField for this. You need to implement something like this:
class FolderSerializer(serializers.ModelSerializer):
files = serializers.SerializerMethodField()
class Meta:
model = Folder
fields = ('name', 'files')
def get_files(self, obj):
result = {'pdf': [], 'txt':[]}
for file in obj.file_set.all():
serializer = FileSerializer(file)
if file.name.endswith('pdf'):
result['pdf'].append(serializer.data)
if file.name.endswith('txt'):
result['txt'].append(serializer.data)
return result

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