序列化类常用字段和字段参数、序列化高级用法之source、序列化高级用法之定制字段的两种方式、多表关联反序列化保存、反序列化字段校验、ModelSerializer使用
序列化类常用字段和字段参数、序列化高级用法之source、序列化高级用法之定制字段的两种方式、多表关联反序列化保存、反序列化字段校验、ModelSerializer使用
昨日作业
题目：原生的request 没有data 属性 实现一个原生的 request.data 拿出无论什么编码格式提交的数
FBV--->写个装饰条
import json
# 通过装饰器写，装饰器视图函数，还有request
def wrapper(func):
def inner(request,*args,**kwargs):
# 创造一个新的request
# request.POST有值的话----->>是urlencoded,form-data编码
# request.POST没有值的话----->>是json编码
try:
print(request.body)
request.data = json.loads(request.body) # json编码
except Exception as e:
request.data = request.POST
res = func(request,*args,**kwargs)
return res
return inner
@wrapper
def test(request)；
print(request.POST) # urlencoded,form-data----->QueryDict
print(request.data) # 报错了
return HttpResponse('ok')
前端提交数据的编码格式：
urlencoded------>>name=lqz&age=19&price=999 放在请求体中
formdata------>>
'----------------------------585520151165741599946333\r\n
Content-Disposition: form-data;
name="name"\r\n\r\nlqz\r\n
----------------------------585520151165741599946333--\r\n'
json------->>{"name":"lqz","age":19}
序列化类常用字段和字段参数
1.常用字段类
1 BooleanField BooleanField()
2 NullBooleanField NullBooleanField()
3 CharField CharField(max_length=None, min_length=None, allow_blank=False, trim_whitespace=True)
4 EmailField EmailField(max_length=None, min_length=None, allow_blank=False)
5 RegexField RegexField(regex, max_length=None, min_length=None, allow_blank=False)
6 SlugField SlugField(max_length=50, min_length=None, allow_blank=False) 正则字段，验证正则模式 [a-zA-Z0-9-]+
7 URLField URLField(max_length=200, min_length=None, allow_blank=False)
8 UUIDField UUIDField(format=’hex_verbose’) format: 1) 'hex_verbose' 如"5ce0e9a5-5ffa-654b-cee0-1238041fb31a" 2） 'hex' 如 "5ce0e9a55ffa654bcee01238041fb31a" 3）'int' - 如: "123456789012312313134124512351145145114" 4）'urn' 如: "urn:uuid:5ce0e9a5-5ffa-654b-cee0-1238041fb31a"
9 IPAddressField IPAddressField(protocol=’both’, unpack_ipv4=False, **options)
10 IntegerField IntegerField(max_value=None, min_value=None)
11 FloatField FloatField(max_value=None, min_value=None)
12 DecimalField DecimalField(max_digits, decimal_places, coerce_to_string=None, max_value=None, min_value=None) max_digits: 最多位数 decimal_palces: 小数点位置
13 DateTimeField DateTimeField(format=api_settings.DATETIME_FORMAT, input_formats=None) # 年月日时分秒
14 DateField DateField(format=api_settings.DATE_FORMAT, input_formats=None) # 年月日
15 TimeField TimeField(format=api_settings.TIME_FORMAT, input_formats=None) # 时分秒
16 DurationField DurationField()
17 ChoiceField ChoiceField(choices) choices与Django的用法相同
18 MultipleChoiceField MultipleChoiceField(choices)
19 FileField FileField(max_length=None, allow_empty_file=False, use_url=UPLOADED_FILES_USE_URL)
20 ImageField ImageField(max_length=None, allow_empty_file=False, use_url=UPLOADED_FILES_USE_URL)
重要的两个字段：
ListField ListField(child=, min_length=None, max_length=None)
DictField DictField(child=)
2.常用字段参数
# CharField及其子类的(EmailField) ---》反序列化的校验
max_length 最大长度
min_lenght 最小长度
allow_blank 是否允许为空
trim_whitespace 是否截断空白字符
# IntegerField
max_value 最小值
min_value 最大值
# 所有字段类都有的
required 表明该字段在反序列化时必须输入，默认True
default 反序列化时使用的默认值
allow_null 表明该字段是否允许传入None，默认False
validators 该字段使用的验证器
----不太重要-----
error_messages 包含错误编号与错误信息的字典
label 用于HTML展示API页面时，显示的字段名称
help_text 用于HTML展示API页面时，显示的字段帮助提示信息
# 重点：
read_only 表明该字段仅用于序列化输出，默认False
write_only 表明该字段仅用于反序列化输入，默认False
序列化高级用法之source(了解)
# 创建关联表
from django.db import models
class Book(models.Model):
name = models.CharField(max_length=32)
price = models.CharField(max_length=32)
publish = models.ForeignKey(to='Publish',on_delete=models.CASCADE)
authors = models.ManyToManyField(to='Author')
class Publish(models.Model):
name = models.CharField(max_length=32)
addr = models.CharField(max_length=32)
class Author(models.Model):
name = models.CharField(max_length=32)
phone = models.CharField(max_length=11)
# 在book中实现publish的名字
def __str__(self):
return self.name
序列化定制字段名字:
from rest_framework import serializers
class BookSerializer(serializers.Serializer):
# 自有字段，直接写字段名字
name_real = serializers.CharField(max_length=32,source='name')
real_price = serializers.CharField(source='price')
# 关联字段，一对多的关联，直接表名点字段
publish = serializers.CharField(source='publish.name')
# 多对多，source不能用
authors = serializers.CharField(source='authors.all')
总结：
重点：source可以指定序列化字段的名字
自有字段，直接写字段名字
-name_real = serializers.CharField(max_length=8, source='name')
关联字段，一对多的关联，直接点
-publish = serializers.CharField(source='publish.name')
多对多，搞不了,source不能用
-authors=serializers.CharField(source='authors.all')
序列化高级用法之定制字段的两种方式
1.SerializerMethodField定制
# 定制关键字的显示形式
一对多形式：显示字典形式
多对多形式：显示列表套字典形式
class BookSerializer(serializers.Serializer):
name = serializers.CharField(max_length=8)
price = serializers.CharField()
# 方法一：SerializerMethodField定制返回格式
publish_detail = serializers.SerializerMethodField()
def get_publish_detail(self,obj):
return {'name':obj.publish.name,'addr':obj.publish.addr}
author_list = serializers.SerializerMethodField()
def get_author_list(self,obj):
l=[]
for author in obj.author.all():
l.append({'name':author.name,'phone':author.phone})
return l
2.在表模型中定制
# 表模型中的代码：
class Publish(models.Model):
name = models.CharField(max_length=32)
addr = models.CharField(max_length=32)
class Author(models.Model):
name = models.CharField(max_length=32)
phone = models.CharField(max_length=11)
class Book(models.Model):
name = models.CharField(max_length=32)
price = models.CharField(max_length=32)
publish = models.ForeignKey(to='Publish',on_delete=models.CASCADE)
authors = models.ManyToManyField(to='Author')
def publish_detail(self):
return {'name':self.publish.name,'addr':self.publish.addr}
def author_list(self):
l = []
for author in self.authors.all():
l.append({'name':author.name,'phone':author.phone})
return l
# 序列化类的代码：
class BookSerializer(serializers.Serializer):
name = serializers.CharField(max_length=8)
price = serializers.CharField()
publish_detail = serializers.DictField()
author_detail = serializers.ListField()
多表关联反序列化保存
1.新增图书接口
# 新增图书接口
-前端传入的数据格式：{name:红楼梦,price:19,publish:1,authors:[1,2]}
# 视图类：
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import Book,Publish,Author
from .Serializer import BookSerializer
class BookView(APIView):
def get(self,request):
books = Book.objects.all()
ser = BookSerializer(instance=books,many=True)
return Response(ser.data)
def post(self,request):
ser = BookSerializer(data=request.data)
if ser.is_valid():
ser.save()
return Response({'code':100,'msg':'新增成功'})
else:
return Response({'code':101,'msg':ser.errors})
# 序列化类
class BookSerializer(serializers.Serializer):
# name和price 既用来序列化，又用来反序列化 即写又读 ,不用加read_only，write_only
name = serializers.CharField(max_length=8)
price = serializers.CharField()
# publish_detail,author_detail,只用来做序列化,加read_only
publish_detail = serializers.DictField(read_only=True)
author_detail = serializers.ListField(read_only=True)
# publish，authors只用来做反序列化 只写 write_only
publish = serializers.CharField(write_only=True)
authors = serializers.ListField(write_only=True)
# 新增重新写create方法
def create(self,validated_data):
# validated_data 校验过后的数据，{name:红楼梦,price:19,publish:1,authors:[1,2]}
# 新增一本图书
book = Book.objects.create(name=validated_data.get('name'), price=validated_data.get('price'),
publish_id=validated_data.get('publish'))
# 作者也要关联上
# book.authors add remove set clear....
book.authors.add(*validated_data.get('authors'))
# book.authors.add(1,2)
return book
2.修改图书接口
# 新增图书接口
前端传入的数据格式：{name:红楼梦,price:19,publish:1,authors:[1,2]}
# 视图类：
from rest_framework.views import APIView
from rest_framework.response import Response
from .models import Book,Publish,Author
from .Serializer import BookSerializer
class BookView(APIView):
def get(self,request):
books = Book.objects.all()
ser = BookSerializer(instance=books,many=True)
return Response(ser.data)
def put(self, request, pk):
book = Book.objects.filter(pk=pk).first()
ser = BookSerializer(data=request.data, instance=book)
if ser.is_valid():
ser.save()
return Response({'code': 100, 'msg': '修改成功'})
else:
return Response({'code': 101, 'msg': ser.errors})
# 序列化类
class BookSerializer(serializers.Serializer):
# name和price 既用来序列化，又用来反序列化 即写又读 ,不用加read_only，write_only
name = serializers.CharField(max_length=8)
price = serializers.CharField()
# publish_detail,author_detail,只用来做序列化,加read_only
publish_detail = serializers.DictField(read_only=True)
author_detail = serializers.ListField(read_only=True)
# publish，authors只用来做反序列化 只写 write_only
publish = serializers.CharField(write_only=True)
authors = serializers.ListField(write_only=True)
# 修改要重写update
def update(self, instance, validated_data):
# validated_data 校验过后的数据，{name:红楼梦,price:19,publish:1,authors:[1,2]}
instance.name = validated_data.get('name')
instance.price = validated_data.get('price')
instance.publish_id = validated_data.get('publish')
# 先清空，再add
authors = validated_data.get('authors')
instance.authors.clear()
instance.authors.add(*authors)
instance.save()
return instance
反序列化字段校验
# 步骤：
-1 字段自己的：举例：name = serializers.CharField(max_length=8, error_messages={'max_length': '太长了'})
-2 validators=[方法，] 忽略掉
-3 局部钩子
-4 全局钩子
ModelSerializer的使用
# ModelSerializer 继承自Serializer，帮咱们完成了很多操作
-跟表模型强关联
-大部分请求，不用写create和update了
# ModelSerializer的使用
class BookSerializer(serializers.ModelSerializer):
# 跟表有关联
class Meta:
model = Book # 跟book表建立了关系 序列化类和表模型类
# fields = '__all__' # 序列化所有Book中的字段 id name price publish authors
fields = ['name', 'price', 'publish_detail', 'author_list', 'publish', 'authors'] # 序列化所有Book中的name和price字段字段
# 定制name反序列化时，最长不能超过8 给字段类加属性---方式一
extra_kwargs = {'name': {'max_length': 8},
'publish_detail': {'read_only': True},
'author_list': {'read_only': True},
'publish': {'write_only': True},
'authors': {'write_only': True},
}
# 如果Meta写了__all__ ,就相当于，复制了表模型中的所有字段，放在了这里，做了个映射
name = serializers.CharField(max_length=32)
price = serializers.CharField(max_length=32)
# 定制name反序列化时，最长不能超过8 给字段类加属性---方式二，重写name字段
# name = serializers.CharField(max_length=8)
# 同理，所有的read_only和wirte_only都可以通过重写或使用extra_kwargs传入
# 序列化类：
publish_detail = serializers.SerializerMethodField(read_only=True)
def get_publish_detail(self, obj):
return {'name': obj.publish.name, 'addr': obj.publish.addr}
author_list = serializers.SerializerMethodField(read_only=True)
def get_author_list(self, obj):
l = []
for author in obj.authors.all():
l.append({'name': author.name, 'phone': author.phone})
return l
def validate_name(self, name):
if name.startswith('sb'):
raise ValidationError('不能sb')
else:
return name
