基于Django的Rest Framework框架的序列化组件

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一 Django自带序列化组件

详见

 

二 rest-framework序列化之Serializer

models部分:

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from django.db import models

# Create your models here.


class Book(models.Model):
    title=models.CharField(max_length=32)
    price=models.IntegerField()
    pub_date=models.DateField()
    publish=models.ForeignKey("Publish")
    authors=models.ManyToManyField("Author")
    def __str__(self):
        return self.title

class Publish(models.Model):
    name=models.CharField(max_length=32)
    email=models.EmailField()
    def __str__(self):
        return self.name

class Author(models.Model):
    name=models.CharField(max_length=32)
    age=models.IntegerField()
    def __str__(self):
        return self.name
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view部分:

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from rest_framework.views import APIView
from rest_framework.response import Response
from .models import *
from django.shortcuts import HttpResponse
from django.core import serializers


from rest_framework import serializers

class BookSerializers(serializers.Serializer):
    title=serializers.CharField(max_length=32)
    price=serializers.IntegerField()
    pub_date=serializers.DateField()
    publish=serializers.CharField(source="publish.name")
    #authors=serializers.CharField(source="authors.all")
    authors=serializers.SerializerMethodField()
    def get_authors(self,obj):
        temp=[]
        for author in obj.authors.all():
            temp.append(author.name)
        return temp
  #此处可以继续用author的Serializers,
  # def get_authors(self,obj):
    # ret=obj.authors.all()
    # ss=AuthorSerializer(ret,many=True)
    # return ss.data
class BookViewSet(APIView): def get(self,request,*args,**kwargs): book_list=Book.objects.all() # 序列化方式1: # from django.forms.models import model_to_dict # import json # data=[] # for obj in book_list: # data.append(model_to_dict(obj)) # print(data) # return HttpResponse("ok") # 序列化方式2: # data=serializers.serialize("json",book_list) # return HttpResponse(data) # 序列化方式3: bs=BookSerializers(book_list,many=True) #many=True代表有多条数据,如果只有一条数据,many=False return Response(bs.data)
     # 序列化方式4:
   # ret=models.Book.objects.all().values(‘nid‘,‘title‘)
     # dd=list(ret)
# return HttpResponse(json.dumps(dd))


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注意:

source 如果是字段,会显示字段,如果是方法,会执行方法,不用加括号(authors=serializers.CharField(source=‘authors.all‘))

如在模型中定义一个方法,直接可以在在source指定执行

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class UserInfo(models.Model):
    user_type_choices = (
        (1,普通用户),
        (2,VIP),
        (3,SVIP),
    )
    user_type = models.IntegerField(choices=user_type_choices)

    username = models.CharField(max_length=32,unique=True)
    password = models.CharField(max_length=64)


#视图
ret=models.UserInfo.objects.filter(pk=1).first()
aa=ret.get_user_type_display()

#serializer
xx=serializers.CharField(source=get_user_type_display)
View Code

 

三 rest-framework序列化之ModelSerializer

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class BookSerializers(serializers.ModelSerializer):
    class Meta:
        model = models.Book
        # fields = "__all__"
        fields=[nid,title,authors,publish]
        # exclude=(‘nid‘,)   #不能跟fields同时用
        # depth = 1    #深度控制,写 几 往里拿几层,层数越多,响应越慢,官方建议0--10之间,个人建议最多3层
    publish=serializers.SerializerMethodField()
    def get_publish(self,obj):
        return obj.publish.name
    authors=serializers.SerializerMethodField()
    def get_authors(self,obj):
        ret=obj.authors.all()
        ss=AuthorSerializer(ret,many=True)
        return ss.data
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四 生成hypermedialink(极少数)

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class BookSerializers(serializers.ModelSerializer):
    class Meta:
        model = models.Book
        fields = "__all__"
    # 生成连接,直接查看出版社详情
    publish = serializers.HyperlinkedIdentityField(view_name=ttt, lookup_field=publish_id, lookup_url_kwarg=pkk)
    authors=serializers.SerializerMethodField()
    def get_authors(self,obj):
        ret=obj.authors.all()
        ss=AuthorSerializer(ret,many=True)
        return ss.data
#--------------

res=BookSerializers(ret,many=True,context=‘request‘: request)
#--------------
class Publish(APIView): def get(self,request,pkk): print(pkk) return HttpResponse(ok) #----路由--- url(r^publish/(?P<pkk>\\d+)$, views.Publish.as_view(),name=ttt),
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 五 序列化组件之请求数据校验和保存功能

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class BookSerializers(serializers.ModelSerializer):
    class Meta:
        model=Book
        fields="__all__"

#————————
class BookView(APIView):

    def post(self, request):

        # 添加一条数据
        print(request.data)

        bs=BookSerializers(data=request.data)
        if bs.is_valid():
            bs.save()  # 生成记录
            return Response(bs.data)
        else:

            return Response(bs.errors)
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class BookSerializer1(serializers.Serializer):
    title=serializers.CharField(error_messages=required: 标题不能为空)

#这种方式要保存,必须重写create方法

 通过源码查看留的校验字段的钩子函数:

 

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#is_valid---->self.run_validation-(执行Serializer的run_validation)-->self.to_internal_value(data)---(执行Serializer的run_validation:485行)
def validate_title(self, value): from rest_framework import exceptions raise exceptions.ValidationError(看你不顺眼) return value

#全局
def validate(self, attrs):
from rest_framework import exceptions
if attrs.get(‘title‘)== attrs.get(‘title2‘):
return attrs
else:
raise exceptions.ValidationError(不想等啊‘)
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序列化组件源码分析

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序列化组件,先调用__new__方法,如果many=True,生成ListSerializer对象,如果为False,生成Serializer对象
序列化对象.data方法--调用父类data方法---调用对象自己的to_representation(自定义的序列化类无此方法,去父类找)
Aerializer类里有to_representation方法,for循环执行attribute = field.get_attribute(instance)
再去Field类里去找get_attribute方法,self.source_attrs就是被切分的source,然后执行get_attribute方法,source_attrs
当参数传过去,判断是方法就加括号执行,是属性就把值取出来
View Code

 

图书的增删查改resful接口:

视图层:

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class BookSerializers(serializers.ModelSerializer):
    class Meta:
        model=models.Book
        fields=__all__


class BookView(APIView):

    def get(self, request):
        book_list = models.Book.objects.all()
        bs = BookSerializers(book_list, many=True)
        # 序列化数据

        return Response(bs.data)

    def post(self, request):
        # 添加一条数据
        print(request.data)

        bs=BookSerializers(data=request.data)
        if bs.is_valid():
            bs.save()  # 生成记录
            return Response(bs.data)
        else:

            return Response(bs.errors)

class BookDetailView(APIView):
    def get(self,request,pk):
        book_obj=models.Book.objects.filter(pk=pk).first()
        bs=BookSerializers(book_obj,many=False)
        return Response(bs.data)
    def put(self,request,pk):
        book_obj = models.Book.objects.filter(pk=pk).first()

        bs=BookSerializers(data=request.data,instance=book_obj)
        if bs.is_valid():
            bs.save() # update
            return Response(bs.data)
        else:
            return Response(bs.errors)
    def delete(self,request,pk):
        models.Book.objects.filter(pk=pk).delete()

        return Response("")
View Code

路由:

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    url(r^books/$, views.BookView.as_view()),
    url(r^books/(?P<pk>\\d+)$, views.BookDetailView.as_view()),
View Code

 

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