Foreign key field disappears in swagger docs after adding depth attribute in Serializer - django-rest-framework

Whenever I define the depth attribute, the foreign key field from swagger docs in POST section disappears. That seems strange because I required depth = 1 when I want related data in my GET request. So I can not remove this in order to get this related field parameter in the POST section.
Here is the case.
Model:
from django.db import models
from django.conf import settings
# Create your models here.
User = settings.AUTH_USER_MODEL
class Todo(models.Model):
user = models.ForeignKey(User)
title = models.CharField("Title", max_length=255)
completed = models.BooleanField("Completed")
Serializer without depth =1.
from rest_framework import serializers
from models import Todo
class TodoSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = Todo
Swagger output:
Now If I add depth = 1 than Swagger does not display related field.
Let me know if anyone has any clue about this.
Thanks :)

Finally after digging into this, I come up with solution by which we can avoid this issue and achieve the expected solution.
So the solution is "Instead of using depth = 1 attribute we can using related serializer instance it self where it works similar to depth functionality."
Here is tested solution
Model:
from django.db import models
from django.conf import settings
User = settings.AUTH_USER_MODEL
class Todo(models.Model):
user = models.ForeignKey(User)
title = models.CharField("Title", max_length=255)
completed = models.BooleanField("Completed")
Serializer
from rest_framework import serializers
from django.conf import settings
from models import Todo
User = settings.AUTH_USER_MODEL
class UserSerializer(serializers.HyperlinkedSerializer):
class Meta:
model = User
class TodoSerializer(serializers.HyperlinkedModelSerializer):
user = UserSerializer()
class Meta:
model = Todo
fields = ('user', 'title', 'completed')
Swagger Output:
This solution is kind of different approach in order to achieve the required functionality, But still I am expecting an official solution from django-rest-swagger team, Even I have posted the same query on django-rest-swagger github repo here.

One solution is to just don't use depth and override to_representation method of serializer:
class TodoSerializer(serializers.ModelSerializer):
class Meta:
model = Todo
def to_representation(self, instance):
r = super(TodoSerializer, self).to_representation(instance)
r.update({'user': UserSerializer().to_representation(instance.user)})
return r
This way, in post everything will be as it was, and in get when return json of todo then to_representation will be called and will add user to json data.

You need to update your serialzer as follows
class TodoSerializer(serializers.HyperlinkedModelSerializer):
creator = serializers.RelatedField(queryset=User.objects.all())
class Meta:
model = Todo
fields = ("name", "task", "creator")
depth = 1
you need to mentions fields and RelatedField in your serializers

Related

Serialize available choices and mark selected

I am new to REST and django-rest-framework. I want to get list of available ManyToMany choices along with some way to know which ones are currently selected.
I have model like this:
class PGroup(models.Model):
.
permissions = models.ManyToManyField(
Permission, related_name="group_permissions", help_text=_('Select permissions for this group.')
)
Serializers.
class PermissionSerializer(serializers.ModelSerializer):
class Meta:
model = Permission
fields = ['pk', 'name',]
class PGroupSerializer(serializers.ModelSerializer):
permissions = PermissionSerializer(many=True)
class Meta:
model = PGroup
fields = [....'permissions']
Looking at Browseable API, with this setup I get 'permissions: []'(empty list) for generics.createAPIView and get the associated 'permissions[....]'(non-empty list) for generics.RetrieveUpdateAPIView.
I want a list of available permissions on both API views and also want to know which permissions are already selected for Update API view.
Can anyone please help.
Thanks
There are 2 ways to get the list of choices.
Using the SerializerMethodField,
from rest_framework import serializers
from .models import Permission
class PGroupSerializer(serializers.ModelSerializer):
permissions = PermissionSerializer(many=True)
all_available_permissions = serializers.SerializerMethodField()
def get_all_available_permissions(self, obj):
return Permission.objects.all()
class Meta:
model = PGroup
fields = ['permissions', "all_available_permissions"]
or using source, we can define a custom method on the model and point the serializer to use it using the source argument.
### models.py
class PGroup(models.Model):
.
permissions = models.ManyToManyField(
Permission, related_name="group_permissions", help_text=_('Select permissions for this group.')
)
def all_permissions(self):
return Permission.objects.all()
### serializers.py
class PGroupSerializer(serializers.ModelSerializer):
permissions = PermissionSerializer(many=True)
all_available_permissions = PermissionSerializer(many=True, read_only=True, source="all_permissions")
class Meta:
model = PGroup
fields = ['permissions', "all_available_permissions"]
2nd option is much better, IMO.
Note: you may not always want to send a full list of choices as that could get really slow overtime when u have hundreds or thousands of objects.

How to get the current logged-in user for schema? (django graphql api)

my goal: I am trying to return all the fields of the posts if the user has an id of 1, and I want to return only 3 fields if else.
My problem is: in the query or mutations I can do info.context.user.id but in the schema I can't do that.
Here in my following code you can noticed his undefined variable current_loggedin_user which I don't know how to get its value.
import graphene
from graphene_django import DjangoObjectType
from . import models
from django.conf import settings
class Posts(DjangoObjectType):
class Meta:
model = models.ExtendUser
if (current_logedin_user.id==1):
field = '__all_'
else:
fields = ['username', 'id', 'imageUrl']
You need to include all fields that are visible to anyone to the schema, and then customize the resolver methods for the fields that you want to hide for some users. For example:
class Posts(DjangoObjectType):
class Meta:
model = models.ExtendUser
def resolve_restricted_field(self, info):
if info.context.user.id == 1:
return self.restricted_field
return None
For more examples, see How to limit field access on a model based on user type on Graphene/Django?
Try something like this
class Posts(DjangoObjectType):
class Meta:
model = models.ExtendUser
class Query(ObjectType):
fields = graphene.List(Posts)
def resolve_fields(self, info, **kwargs):
if info.context.user.pk == 1:
return ExtendUser.objects.all()
return ExtendUser.objects.values_list('username', 'id', 'imageUrl', flat=True)

Apply filters to any or a certain many-to-many record

Consider these models:
from django.db import models
class Group(models.Model):
name = models.CharField()
class Person(models.Model):
height = models.PositiveIntegerField()
weight = models.PositiveIntegerField()
gender = models.CharField()
groups = models.ManyToManyField(Group, blank=True)
and the DRF views
from rest_framework import viewsets
from rest_framework.filters import SearchFilter, OrderingFilter
from django_filters import rest_framework as filters
from .serializers import GroupSerializer
from ..models import Group
class GroupViewSet(viewsets.ModelViewSet):
queryset = Group.objects.all().distinct()
serializer_class = GroupSerializer
filter_backends = (filters.DjangoFilterBackend,
SearchFilter, OrderingFilter)
filter_class = GroupFilter
A group can have 0,1,2 or more Persons, with 1 and 2 being the most common and where these 1 and 2 are clearly defined. Think of it as Facebook's chat: you have one-on-one chat most commonly, but sometimes you can have a group chat. When is one-one-one chat, 1 is sender, 2 is receiver.
I need to filter these records from DRF, when browsing the GroupViewSet and filter by Person attributes, where I can apply a group of filters to any Person or a certain Person.
For any person, no matter to which a certain condition is applied, is clear:
/api/group/?person__height__gt=100&person__weight__gt=200
But for a certain person, where a group of conditions apply to that person, in the URL, I could have something like:
/api/group/?person__0__height__gt=100&person__0__weight__gt=200&person__1__height__lte=200
And declare these into my custom FilterSet:
from django.db.models.constants import LOOKUP_SEP
class GroupFilter(filters.FilterSet):
person__0__height = filters.NumberFilter(method='person_filter')
person__0__height__gt = filters.NumberFilter(method='person_filter')
person__0__height__lt = filters.NumberFilter(method='person_filter')
# ... and so on for the rest of the possibilities
def person_filter(self, queryset, name, value):
m2mfield, index, field, *comparison = name.split(LOOKUP_SEP, 3)
# do subqueries based on the above and construct queryset filter.
But as you can imagine, this implies that I'll have a lot of boilerplate code. In my real models there are many fields and the above "solution" seems hacky to me.
So the question is: is there an easier/cleaner way to achieve the above filtering?
Maybe by dynamically declaring the person__0__height__gt attributes, for which I couldn't yet find a solution.
Note that I do not know the IDs of the Person entities upfront. Those person__0, person__1 are array indexes.
try this for cleaning code :
class GroupFilter(django_filters.FilterSet):
person_range = django_filters.NumericRangeFilter(field_name='person__0__height', lookup_expr='range')
person = django_filters.NumberFilter(field_name='person__0__height', lookup_expr='exact')
class Meta:
model = Group
fields = ('person_range','person',)
and call with url like this :
127.0.0.1:8000/yourpath/?person=180&person_range_min=130&person_range_max=210

How to write a generic CRUD service on django using rest framework?

I am new to django and faced to several problems trying to write a simple service.
What am I trying to do?
I intend to write a generic crud service for my models using rest-framework library.
I don't want to write serializers and views to all my models and trying to optimize code and learn some useful stuff.
My model
Let's imagine I have an abstract BaseBusinessObject
class BaseBusinessObject(models.Model):
CreatedAt = models.DateField()
UpdatedAt = models.DateField()
class Meta:
abstract = True
I also have a plenty of concrete classes, which are inherited from base one:
class Product(BaseBusinessObject):
Description: models.TextField()
Type: models.CharField()
....
class Company(BaseBusinessObject):
Title: models.CharField()
....
class Person(BaseBusinessObject):
Name: models.CharField()
and so on
What I want
I already figured out, that with rest-framework I can create serializers and views, then register router for url .../Product, .../Company, .../Person. But what if I have 1000 classes? This is boring
A. How can I dynamically specified url's for child objects? I don't want to hardcode methods, I am looking for solution...something like this:
.../api/Entities/ClassName
B. How can I then use my dynamically created urls in django-rest-framework?
router.register('persons', PersonViewSet)
How can write it in more generic way?
router.register('<ClassName>', <GenericViewSet>)
C. Using DRF I can create my viewset for each concrete class in my model:
class PersonViewSet(viewsets.ModelViewSet):
queryset = Person.objects.all()
serializer_class = PersonSerializer
But as I said I have a lot of classes. How can I write it in more generic way?
I tried to create a view set for abstract class, but there are some trouble when querying an abstract object.
Is it possible to create such service for an abstract class and then all its child simply(or not simply) inherit CRUD methods?
Maybe I should try to write a factory for serializers and viewsets?
What possible solutions could I implement for solving my problem?
After 2 days of walking around I finally find my solution. May be someone else will face the some problem, so I trying to explain what I had already done.
First, I create a "base" application inside my django project and add it to settings.py. Then I create an abstract class in models.py:
class BaseCrudEntity(models.Model):
pass
class Meta:
abstract = True
I want to write a generic service for CRUD operations for all "business" classes.
The problem is that I don't want to write serializers and views for them - I want to create them "on fly", dynamically. I decided to use django rest framework as well, because I am not intended to create a bycicle again.
I decided to inherit all my "business" classes from that abstract one and write a service for all possible "families"
So I have to create a fabric which is responsible for VeiwSet creation.
Here is my view.py:
class BaseCrudViewSetFabric():
#classmethod
def CreateViewSet(self, _context):
classname = _context.__name__ + 'ViewSet'
return type(classname, (viewsets.ModelViewSet,), {
'queryset':_context.objects.all(),
'serializer_class':BaseCrudSerializerFabric.CreateSrializer(_context)
})
pass
here _context - variable which describes concrete class of my model.
as you can see this function creates a concrete ViewSet based on my context. Inside it a Serializers fabric is called.
Here the code of my serializers.py:
class BaseCrudSerializerFabric():
#classmethod
def CreateSrializer(self, _context):
classname = _context.__name__
_Meta = type('Meta', (), {'model':_context,'fields':'__all__'})
_crudserializer = type(
classname,
(serializers.ModelSerializer,),
{'Meta': _Meta}
)
return _crudserializer
Moreover, I have to write a service for dynamically routing - I don't wanna hardcode my urls.
Here the example ursl.py from core project:
from base.urls import router
url(r'^api/v1/', include(router.urls))
and from base/urls.py:
from rest_framework.routers import DefaultRouter, SimpleRouter
from base.models.BaseCrudEntity import BaseCrudEntity
from base.views.basecrud_view import BaseCrudViewSetFabric
class CustomRouter(SimpleRouter):
def RoutRegister(self):
childs = getChilds(BaseCrudEntity)
#print(childs)
for ch in childs:
if (ch._meta.abstract == False):
#print(ch.__name__)
prefix = ch.__name__
self.register(prefix, BaseCrudViewSetFabric.CreateViewSet(ch))
return(self)
pass
router = CustomRouter()
router.RoutRegister()
Finally I simply create some concrete models:
from django.db import models
from base.models.BaseCrudEntity import BaseCrudEntity
class Person(BaseCrudEntity):
Name = models.CharField(max_length = 255)
Surname = models.CharField(max_length = 255)
Patronymic = models.CharField(max_length = 255, null = True)
DateOfBirth = models.DateField(null = True)
#slug = models.SlugField(default = 'hui', editable = False)
def __str__(self):
return "{} {} {}".format (self.Surname, self.Name, self.Patronymic)
and thats all.
When application starts it register a route for http://127.0.0.1:8000/api/v1/Person and creates serializers and viewsets so all CRUD operations provided by Django- Rest Framework will be provided as well.
I would suggest using query parameters instead of path parameters, then you just register one URL and process the various elements of the request and route it correctly server-side. When do I use path params vs. query params in a RESTful API?

DRF - in filter, use field-value instead of default pk / id

I'm trying to use DRF's filters so that the URL query is like so:
/roadname/?road=M5
not like so
/roadinfo/?road=1
I can't seem to do it when I've got a ForeignKey relationship.
I've tried using lookup_field with no luck (although not sure how this would work for multiple filter fields anyway - I don't think that's the answer). I've tried using a get_queryset() method in views as in the second example in the documentation. A comment I came across suggested that this is bad RESTApi practice - is it? How would a user know to type in '1' to get results for 'M5' in a front-end client?
I've set up two really simple models (and serializers, views, etc.) to try these out as below.
If I use RoadName, I have to type the name into the filter search box (rather than having a dropdown), but the url query is how I want it.
If I use RoadInfo (which has a ForeignField to RoadName), I get a drop down in the filter box, but the url query uses the ForeignKey pk.
My question: How can I set it so that when I use RoadInfo, the query uses the field value rather than the id/pk?
Models
from django.db import models
class RoadName(models.Model):
road = models.CharField(max_length=50)
def __str__(self):
return str(self.road)
class RoadInfo(models.Model):
road = models.ForeignKey(RoadName, on_delete='CASCADE')
# other data
def __str__(self):
return str(self.road)
Serializers
from traffic.models import *
from rest_framework import serializers
class RoadNameSerializer(serializers.ModelSerializer):
road = serializers.CharField()
class Meta:
model = RoadName
exclude = ('id',)
class RoadInfoSerializer(serializers.ModelSerializer):
road = RoadNameSerializer()
class Meta:
model = RoadInfo
exclude = ('id',)
Views
from traffic.serializers import *
from traffic.models import *
from django_filters import rest_framework as filters
from rest_framework import viewsets
class RoadNameViewSet(viewsets.ReadOnlyModelViewSet):
""" List of all traffic count Counts """
queryset = RoadName.objects.all()
serializer_class = RoadNameSerializer
filter_backends = (filters.DjangoFilterBackend,)
filterset_fields = '__all__'
class RoadInfoViewSet(viewsets.ReadOnlyModelViewSet):
""" List of all traffic count Counts """
queryset = RoadInfo.objects.all()
serializer_class = RoadInfoSerializer
filter_backends = (filters.DjangoFilterBackend,)
filterset_fields = '__all__'
The data M5 on the road attribute of RoadName model. It can be filtered by road__road from RoadInfo model.
So, Try /roadname/?road__road=M5

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