序列化组件进阶
简单认识序列化
1 序列化模型类：api/models.py
# 自定义model类的方法属性，完成插拔式跨表查询
class Book(BaseModel):
# ...
@property
def publish_name(self):
return self.publish.name
@property
def authors_info(self):
author_list = []
for author in self.authors.all():
author_list.append({
'name': author.name,
'age': author.age,
'mobile': author.detail.mobile
})
return author_list
class Author(BaseModel):
# ...
@property
def mobile(self):
return self.detail.mobile
2 序列化类：api/serializers.py
from rest_framework import serializers
from . import models
"""
序列化总结：
1）在自定义的ModelSerializer类中设置class Meta
model 绑定序列化相关的模型类
fields 插拔方式指定序列化字段
2）在模型类中通过 方法属性 自定义连表查询的字段，在fields中插拔
3）如果就使用外键字段完成连表深度查询，用 序列化深度
外键字段 = 外键序列化类(many=True|False)
"""
class PublishModelSerializer(serializers.ModelSerializer):
class Meta:
model = models.Publish
fields = ('name', 'address')
class AuthorModelSerializer(serializers.ModelSerializer):
class Meta:
model = models.Author
fields = ('name', 'age', 'mobile')
class BookModelSerializer(serializers.ModelSerializer):
# 正向序列化深度
# (不建议：必须用外键名才需要序列化深度，
# 建议：自定义外键序列化名，在model类中插拔字段(属性方法))
publish = PublishModelSerializer()
authors = AuthorModelSerializer(many=True)
# 了解：在ModelSerializer中不建议使用，如何书写了必须在fields中声明使用
# p_n = serializers.SerializerMethodField()
# def get_p_n(self, obj: models.Book):
# return obj.publish.name
class Meta:
model = models.Book
fields = ('name', 'price', 'img', 'publish_name', 'authors_info', 'publish', 'authors')
# 了解
# fields = '__all__' # 所有字段
# # exclude = ('id', 'is_delete') # 刨除某些字段
# depth = 1 # 跨表自动深度（展示外键表的所有字段）
3 序列化视图类：api/views.py
from rest_framework.views import APIView
from utils.response import APIResponse
from . import models, serializers
class BookAPIView(APIView):
def get(self, request, *args, **kwargs):
book_query = models.Book.objects.all()
book_ser = serializers.BookModelSerializer(book_query, many=True)
return APIResponse(0, 'ok', results=book_ser.data)
简单认识反序列化
反序列化模型类：api/models.py
# 自定义model类的方法属性，完成插拔式跨表查询
class Book(BaseModel):
# ...
@property
def publish_name(self):
return self.publish.name
@property
def authors_info(self):
author_list = []
for author in self.authors.all():
author_list.append({
'name': author.name,
'age': author.age,
'mobile': author.detail.mobile
})
return author_list
class Author(BaseModel):
# ...
@property
def mobile(self):
return self.detail.mobile
反序列化类：api/serializers.py
"""
反序列化总结：
1）在自定义的ModelSerializer类中设置class Meta
model 绑定反序列化相关的模型类
fields 插拔方式指定反序列化字段
extra_kwargs 定义系统校验字段的规则
2）可以自定义局部钩子和全局钩子完成字段的复杂校验规则
3）不需要重写create和update完成增加修改，ModelSerializer类已经帮我们实现了
"""
class BookModelDeserializer(serializers.ModelSerializer):
class Meta:
model = models.Book
fields = ('name', 'price', 'publish', 'authors')
extra_kwargs = {
'name': {
'min_length': 3,
'error_messages': {
'min_length': '太短'
}
},
'publish': {
'required': True
},
'authors': {
'required': True
},
}
# 自定义校验
# 这个反序列化封装的非常全面
# 这里面封装了 比如你传过来一个外键名要和orm名字对上，
def validate_name(self, value):
if 'sb' in value:
raise serializers.ValidationError('书名有敏感词汇')
return value
def validate(self, attrs):
name = attrs.get('name')
publish = attrs.get('publish')
# 注意这个publish 已经是一个model对象了
# 这个publish = publish 内部会自动转化为 publish_id = publish.id
if models.Book.objects.filter(name=name, publish=publish):
raise serializers.ValidationError({'book': '书籍以存在'})
return attrs
序列化视图类：api/views.py
from rest_framework.views import APIView
from utils.response import APIResponse
from . import models, serializers
class BookAPIView(APIView):
def get(self, request, *args, **kwargs):
book_query = models.Book.objects.all()
book_ser = serializers.BookModelSerializer(book_query, many=True)
return APIResponse(0, 'ok', results=book_ser.data)
def post(self, request, *args, **kwargs):
book_ser = serializers.BookModelDeserializer(data=request.data)
if book_ser.is_valid():
book_ser.save()
return APIResponse(0, 'ok')
else:
return APIResponse(1, '添加失败', results=book_ser.errors)
序列化与反序列化共存（重点）
路由：api/urls.py
from django.conf.urls import url
from . import views
urlpatterns = [
# ...
url(r'^v2/books/$', views.BookV2APIView.as_view()),
url(r'^v2/books/(?P<pk>.*)/$', views.BookV2APIView.as_view()),
]
模型层修订：api/models.py
class Book(BaseModel):
# ...
class Meta:
# ...
# 联合唯一 => patch结果修改部分数据就会收到'name'、'publish'联合限制
unique_together = ('name', 'publish')
序列化层：api/serializers.py
class BookV2ModelSerializer(serializers.ModelSerializer):
class Meta:
model = models.Book
# 序列化和反序列化一体
# 这个地方先写完反序列化字，并且把只需要反序列化字段的内容摘出来写上write_only:True
# 反序列化字段 'name','price','publish','authors'
# 序列化字段 'name','price','img','publish_name','authors_info'
# 感觉这个序列化和反序列化不实用。
# 又或者单独做序列化比较实用，反序列化并不实用感觉。
# 使用逻辑：
# 首先写反序列化的内容 都写上 write_only
# 其次写序列化的内容 都写上read_only 如果有和反序列化重合的则去掉之前反序列化的write_only
fields = ('name', 'price', 'publish', 'authors', 'img', 'publish_name', 'authors_info')
extra_kwargs = {
'publish': {
'required': True,
'write_only': True
},
'authors': {
'required': True,
'write_only': True
},
'img': {
'read_only': True
}
}
def validate_name(self, value):
if 'sb' in value:
raise serializers.ValidationError('书名有敏感词汇')
return value
def validate(self, attrs):
name = attrs.get('name')
publish = attrs.get('publish')
# 注意这个publish 已经是一个model对象了
# 这个publish = publish 内部会自动转化为 publish_id = publish.id
if models.Book.objects.filter(name=name, publish=publish):
raise serializers.ValidationError({'book': '书籍以存在'})
return attrs
视图层：api/views.py
class BookV2APIView(APIView):
def get(self, request, *args, **kwargs):
book_query = models.Book.objects.filter(is_delete=False).all()
book_ser = serializers.BookV2ModelSerializer(book_query, many=True)
return APIResponse(0, 'ok', results=book_ser.data)
def post(self, request, *args, **kwargs):
book_ser = serializers.BookV2ModelSerializer(data=request.data)
if book_ser.is_valid():
book_obj = book_ser.save()
return APIResponse(0, 'ok',
results=serializers.BookV2ModelSerializer(book_obj).data
)
else:
return APIResponse(1, '添加失败', results=book_ser.errors)
## 局部修改
def patch(self, request, *args, **kwargs):
pk = kwargs.get('pk')
if not pk:
return APIResponse(1, 'pk error')
try:
book_obj = models.Book.objects.get(is_delete=False, pk=pk)
except:
return APIResponse(1, 'pk no book')
book_ser = serializers.BookV2ModelSerializer(partial=True, instance=book_obj, data=request.data)
if book_ser.is_valid():
book_obj = book_ser.save()
return APIResponse(1, 'ok',
results=serializers.BookV2ModelSerializer(book_obj).data
)
else:
return APIResponse(1, '更新失败', results=book_ser.errors)
def delete(self, request, *args, **kwargs):
# 单删 /books/(pk)/
# 群删 /books/ 数据包携带 pks => request.data
pk = kwargs.get('pk')
if pk:
pks = [pk]
else:
pks = request.data.get('pks')
if not pks:
return APIResponse(1, '删除失败')
book_query = models.Book.objects.filter(is_delete=False, pk__in=pks)
print(book_query)
if not book_query.update(is_delete=True): # 受影响的行得大于0
return APIResponse(1, '删除失败')
return APIResponse(0, '删除成功')
