rest-framework序列化

将数据显示到页面上，在后端需要对其及进行序列化处理
参考文档：https://www.cnblogs.com/glh-ty/p/9671397.html

1.用原生的HttpResponse处理

from django.views import View
from app01 import models
import json
class BookView(View):
    def get(self,request):
        book_obj=models.Book.objects.all()
        #将每个对象都取出来，放到列表中，序列化后返回
        temp=[]
        for obj in book_obj:
            temp.append({
                "pk":obj.pk,
                "title":obj.title
            })
        return HttpResponse(json.dumps(temp))

2.使用rest_framework的响应处理

from rest_framework.response import Response
class BookView(View):
    def get(self,request):
        book_obj=models.Book.objects.all()
        #将每个对象都取出来，放到列表中，序列化后返回
        temp=[]
        for obj in book_obj:
            temp.append({
                "pk":obj.pk,
                "title":obj.title
            })
        return Response(json.dumps(temp))

同时在INSTALLED_APPS加入"rest_framework"，上述方法不足之处：当字段很多时，我们要写入多个字段，不方便

使用restframework进行序列化

方法一：model_to_dict(obj)

class BookView(APIView):
    def get(self,request):
        book_obj=models.Book.objects.all() 
        from django.forms.models import model_to_dict
        temp = []
        for book in book_obj:
            temp.append(model_to_dict(book))
        return Response(json.dumps(temp))
页面显示："[{"id": 2, "title": "python"}, {"id": 3, "title": "go"}]"

方法二：serialize

class BookView(APIView):
    def get(self,request):
        book_obj=models.Book.objects.all() 
        from django.core.serializers import  serialize
        ret=serialize("json",book_obj)
        return Response(ret)
"[{"model": "app01.book", "pk": 2, "fields": {"title": "python"}}, 
{"model": "app01.book", "pk": 3, "fields": {"title": "go"}}]"

方法三：序列化组件 rest_framework组件中serializers，使用如同form组件：

不仅可以序列化queryset也可以序列化对象

自定义类，继承serializers

rom rest_framework import serializers
class BookSerializers(serializers.Serializer):
    title=serializers.CharField(max_length=32)

class BookView(APIView):
    def get(self,request):
        book_list=models.Book.objects.all()
        bs = BookSerializers(book_list, many=True)
            return Response(bs.data)

如果要显示其他的字段就在BookSerializers设定其他的字段
在设定ForeignKey和ManyToManyField的操作:
ForeignKey:
publish=serializers.CharField(max_length=32,source="publish.name")
设置source，可任意设置要显示的对象属性。如果模型表中国没设置返回name，这里也没设置source
则显示：

{
        "title": "python",
        "price": "110.00",
        "publish": "Publish object"
}

ManyToManyField：
如果使用ForeignKey的显示方式，则应该：
authors=serializers.CharField(max_length=32,source="authors.all")
页面上的作者显示的都是具体的对象：

[
    {
        "title": "python",
        "price": "110.00",
        "publish": "北京出版社",
        "authors": "<QuerySet [<Author: jerd>, <Author: jerry>]>"
    },
    {
        "title": "go",
        "price": "110.00",
        "publish": "天青烟雨出版社",
        "authors": "<QuerySet [<Author: jerry>]>"
    }
]

而我们需要显示的是对应的作者对象姓名,定义get_+字段名函数

authors=serializers.SerializerMethodField()
def get_authors(self,obj):
    temp=[]
    for obj in  obj.authors.all():
        temp.append(obj.name)
    return temp

[
    {
        "title": "python",
        "price": "110.00",
        "publish": "北京出版社",
        "authors": [
            "jerd",
            "jerry"
        ]
    },
    {
        "title": "go",
        "price": "110.00",
        "publish": "天青烟雨出版社",
        "authors": [
            "jerry"
        ]
    }
]

bs=BookSerializers(book_list,many=True)的效果等同于

temp=[]
for obj in book_list:

    temp.append({
          'title':obj.title,
          'price':obj.price,
          'publish':obj.publish.name,
          'authors':
    })
bs.data=json.dumps(temp)