python - 如何将 DRF 序列化器与 Graphene 一起使用

Question

我正在关注 this tutorial将 Graphene 与 Django 一起使用，一切都很顺利，直到我到达 Integration with Django Rest Framework section .

本节说您可以通过创建序列化器克隆来将 DRF 序列化器与 Graphene 重用，但它没有说明如何处理这些克隆以便重用DRF 序列化器与 Graphene。

这些是我的序列化器和克隆:

from rest_framework import serializers
from graphene_django.rest_framework.mutation import SerializerMutation
from GeneralApp.models import Airport
from ReservationsManagerApp.serializers import ReservationSerializer
from ReservationsManagerApp.models import ReservationComponent, ReservationHotel, ReservationRoundtrip, ReservationTransfer, ReservationTour, ReservationService, Hotel

class ReservationMutation(SerializerMutation):
    class Meta:
        serializer_class = ReservationSerializer

class ReservationComponentGraphSerializer(serializers.ModelSerializer):
    component = serializers.SerializerMethodField()

    class Meta:
        model = ReservationComponent
        fields = ('id', 'reservation', 'dertour_bk', 'day', 'content_type', 'object_id', 'comment', 'is_invoiced', 'component')

    def get_component(self, instance):
        components_models = {
            'reservationhotel': ReservationHotel,
            'reservationroundtrip': ReservationRoundtrip,
            'reservationtransfer': ReservationTransfer,
            'reservationtour': ReservationTour,
            'reservationservice': ReservationService,
        }

        component = components_models[instance.content_type.model].objects.get(id=instance.object_id)

        return self.get_component_string(instance.content_type.model, component)

    def get_component_string(self, component_model, component):
        components_get_string = {
            'reservationhotel': self.get_hotel_string,
            'reservationroundtrip': self.get_roundtrip_string,
            'reservationtransfer': self.get_transfer_string,
            'reservationtour': self.get_tour_string,
            'reservationservice': self.get_service_string,
        }

        return components_get_string[component_model](component):

    def get_hotel_string(self, component):
        return component.hotel.name

    def get_roundtrip_string(self, component):
        return component.roundtrip.name

    def get_transfer_string(self, component):
        origin_str = self.get_place_str('origin', component)
        destination_str = self.get_place_str('destination', component)

        return "{} => {}".format(origin_str, destination_str)

    def get_place_str(self, case, component):
        places_models = {
            'airport': Airport,
            'hotel': Hotel,
        }

        if case == 'origin':
            return places_models[component.origin_content_type.model].objects.get(id=component.origin_object_id).name
        else:
            return places_models[component.destination_content_type.model].objects.get(id=component.destination_object_id).name

    def get_tour_string(self, component):
        return component.tour.name

    def get_service_string(self, component):
        return component.service.name

class ReservationComponentMutation(SerializerMutation):
    class Meta:
        serializer_class = ReservationComponentGraphSerializer

这是我的schemas.py:

import graphene
from graphene_django.types import DjangoObjectType
from ReservationsManagerApp.models import   Reservation, ReservationComponent
from InvoicesManagerApp.models import Invoice, InvoiceEntry, InvoiceEntryComponent
from PaymentsManagerApp.models import Payment, PaymentReservationComponent

class ReservationType(DjangoObjectType):
    class Meta:
        model = Reservation

class ReservationComponentType(DjangoObjectType):
    class Meta:
        model = ReservationComponent

class InvoiceType(DjangoObjectType):
    class Meta:
        model = Invoice

class InvoiceEntryType(DjangoObjectType):
    class Meta:
        model = InvoiceEntry

class InvoiceEntryComponentType(DjangoObjectType):
    class Meta:
        model = InvoiceEntryComponent

class PaymentType(DjangoObjectType):
    class Meta:
        model = Payment

class PaymentReservationComponentType(DjangoObjectType):
    class Meta:
        model = PaymentReservationComponent

class  Query(object):
    all_reservations = graphene.List(ReservationType)
    all_reservation_components = graphene.List(ReservationComponentType)
    all_invoices = graphene.List(InvoiceType)
    all_invoice_components = graphene.List(InvoiceEntryType)
    all_invoice_entries_components = graphene.List(InvoiceEntryComponentType)
    all_payment = graphene.List(PaymentType)
    all_payment_reservation_components = graphene.List(PaymentReservationComponentType)

    def resolve_all_reservations(self, info, **kwargs):
        return Reservation.objects.all()

    def resolve_all_reservation_components(self, info, **kwargs):
        return ReservationComponent.objects.select_related('reservation').all()

    def resolve_all_invoice_entries_components(self, info, **kwargs):
        return InvoiceEntryComponent.objects.select_related('reservation_component').all()

    def resolve_all_payment_reservation_components(self, info, **kwargs):
        return PaymentReservationComponent.objects.select_related('reservation_component').all()

我不知道我是否遗漏了一些明显的东西，但我不明白我应该如何将这些序列化器突变与 Graphite 烯一起使用。我想这一定是通过以某种方式配置 Query 类，但我在文档中找不到引用。

Answer 1

我看不出有任何理由必须按照该教程中的说明进行操作。通过以下方式连接 drf 和 graphql 会容易得多。这样做，您无需担心任何模糊类，只需依赖 drf 和 Graphite 烯的主要方面。

正常构建drf序列化器，如下图连接到graphql。

假设我们有模型 Subject。让我们为它创建 CRUD api。

from graphene.types.scalars import Scalar

class ObjectField(Scalar): # to serialize error message from serializer
    @staticmethod
    def serialize(dt):
        return dt 


class SubjectType(DjangoObjectType):
    class Meta:
        model=Subject


# For mutation, use serializers

#creating subject
class CreateSubject(graphene.Mutation):
    subject=graphene.Field(SubjectType)
    message=ObjectField()
    status=graphene.Int()

    class Arguments:
        name=graphene.String(required=True)
        description=graphene.String(required=True)
   
    @classmethod
    def mutate(cls,root,info,**kwargs):
        serializer=SubjectSerializer(data=kwargs)
        if serializer.is_valid():
            obj=serializer.save()
            msg='success'
        else:
            msg=serializer.errors
            obj=None
            print(msg)
        return cls(subject=obj,message=msg,status=200)


'''Updating subject'''
class UpdateSubject(graphene.Mutation):
    subject=graphene.Field(SubjectType)
    status=graphene.Int()
    message=ObjectField()

    class Arguments:
        id=graphene.ID(required=True)
        name=graphene.String()
        description=graphene.String()

    @classmethod
    def mutate(cls,root,info,id,**kwargs):
        sub=Subject.objects.get(id=id)
        serializer=SubjectSerializer(sub,data=kwargs,partial=True)
        if serializer.is_valid():
            obj=serializer.save()
            msg='success'
        else:
            msg=serializer.errors
            obj=None
            print(msg)
        return cls(subject=obj,message=msg,status=200)


'''Delete Subject'''
class DeleteSubject(graphene.Mutation):
    message=ObjectField()
    status=graphene.Int()

    class Arguments:
        id=graphene.ID(required=True)

    @classmethod
    def mutate(cls,root,info,id,**kwargs):
        c=Subject.objects.get(id=id)
        c.delete()
        return cls(message='success',status=200)


class Mutation(graphene.ObjectType):
    create_subject=CreateSubject.Field()
    update_subject=UpdateSubject.Field()
    delete_subject=DeleteSubject.Field()

# Query is normal.

class Query(graphene.ObjectType):
    subject=graphene.Field(SubjectType,id=graphene.Int(), slug=graphene.String())
    
    subjects=graphene.List(SubjectType)

    def resolve_subject(self, info, id=None, slug=None):
        if id:
            return Subject.objects.get(id=id)
        if slug:
            return  Subject.objects.get(slug=slug)

    def resolve_subjects(self,info,**kwargs):
        return Subject.objects.all()

    

您可以尝试为自己制作一些类似框架的东西，以避免出现冗余代码。