drf序列化器使用时性能优化之根据请求类型动态变更serializer及个性化序列化字段及 Django REST-FlexFields使用 - 《python web 开发》

drf序列化器使用时性能优化之根据请求类型动态变更serializer及个性化序列化字段及 Django REST-FlexFields使用

`drf`序列化器使用时性能优化之`根据请求类型动态变更serializer`及个性化序列化字段及 `Django REST-FlexFields`使用

`根据请求类型动态变更serializer`

我们在drf开发中我们遇到增删改查数据时，会遇到一些针对于增删改查的不同请求的json请求，我们可以使用不同的序列化器满足需求，闲话少说，直接上代码吧

首先我们定义相关的models.py中添加相关的模型

from django.db import models
class BookModels(models.Model):
    id = models.BigAutoField("图书记录id号", primary_key=True)
    Isbn_Card = models.CharField("图书isbn码", max_length=30, null=False, )
    Book_Name = models.CharField("图书名称", max_length=100, null=False, blank=False)
    Book_author = models.CharField("图书作者", max_length=100, null=False, blank=False)
    Book_press = models.CharField("图书出版社", max_length=100, null=False, blank=False)
    Book_stock = models.IntegerField("图书库存", default=0, null=False, blank=False)
    Book_Creation_time = models.DateField("图书入库时间", auto_now_add=True, null=False, blank=False)
    Book_notes = models.TextField("简介备用", null=False, blank=False)
    Price = models.DecimalField("图书单价", max_digits=10000, decimal_places=2, null=False, blank=False, default=0)
    class Meta:
        verbose_name = "图书信息管理"
        db_table = "BookInfo_Table"
        verbose_name_plural = verbose_name
    def __str__(self):
        return f"{self.id}:{self.Isbn_Card}: {self.Book_Name}: {self.Book_author}:{self.Book_press}"
class BookAnother(models.Model):
    name = models.CharField("name", max_length=12)
    BookModel = models.ForeignKey(BookModels, on_delete=models.DO_NOTHING, verbose_name="图书信息管理", null=True)
    class Meta:
        verbose_name = "BookAnother"
        db_table = "BookAnother_Table"
        verbose_name_plural = verbose_name

其次在Serializer.py中新建相关的序列化器

# -*- coding: utf-8 -*-
# @Time    : 2021/2/9 下午3:09
# @Author  : void bug
# @FileName: Serializer.py
# @Software: PyCharm
from rest_framework import serializers
from apps.Book.models import *
class BookSerializers(serializers.ModelSerializer):
    class Meta:
        model = BookModels
        fields = '__all__'
class BookAnotherUpDateSerializer(serializers.ModelSerializer):
    class Meta:
        model = BookAnother
        fields = ("name",)
class BookAnotherSerializer(serializers.ModelSerializer):
    class Meta:
        model = BookAnother
        fields = '__all__'

最后我们编写相关的ViewSet.py文件

# -*- coding: utf-8 -*-
# @Time    : 2021/2/9 下午3:12
# @Author  : void bug
# @FileName: ViewSet.py
# @Software: PyCharm
from rest_framework import viewsets
from apps.Book.Serializer import *
class BookViewSet(viewsets.ModelViewSet):
    serializer_class = BookSerializers
    queryset = BookModels.objects.all()
class BookAnotherViewSet(viewsets.ModelViewSet):
    serializer_class = BookAnotherSerializer
    queryset = BookAnother.objects.all()
    def get_serializer_class(self):
        # 根据请求类型动态变更serializer
        if self.action == "update":
            return BookAnotherUpDateSerializer
        return BookAnotherSerializer

我们看下效果

个性化序列化字段

先在我们实现了根据请求类型动态变更serializer，但是现在进行一些优化，但是我们为什么要进行优化呢，现在我们修改成功后只显示了 name 字段，但是我们修改成功后应该时都显示出来，故现在我们只需要修改BookAnotherViewSet.py即可

class BookAnotherUpDateSerializer(serializers.ModelSerializer):
    name = serializers.CharField(max_length=12, read_only=True)
    class Meta:
        model = BookAnother
        fields = '__all__'

我们看下效果

`Django REST-FlexFields`使用

好的我们已经实现了上述的功能了，但是我们现在项显示相关的外键的信息，现在我们需要导入一个外键的包Django REST-FlexFields

Django REST Framework序列化程序的灵活，动态字段和嵌套模型。
总览
用于Django REST Framework的FlexFields（DRF-FF）是一个软件包，旨在为在DRF序列化程序中动态设置字段和嵌套模型提供功能的通用基准。该软件包的设计旨在简化，与DRF的基础类的纠缠最少。
主要优点：
- 通过查询参数（users/?expand=organization,friends）轻松设置可扩展为完全序列化的字段
- 通过以下任一方法选择字段的子集：
  - 指定应包含哪些（users/?fields=id,first_name）
  - 指定应排除的项目（users/?omit=id,first_name）
- 使用点表示法可动态修改任意深度的字段（users/?expand=organization.owner.roles）
- 灵活的API-选项也可以直接传递给序列化器： UserSerializer(obj, expand=['organization'])

安装

pip install drf-flex-fields

配置序列化器

然后让您的序列化器子类FlexFieldsModelSerializer：

# -*- coding: utf-8 -*-
# @Time    : 2021/2/9 下午3:09
# @Author  : void bug
# @FileName: Serializer.py
# @Software: PyCharm
from rest_flex_fields import FlexFieldsModelSerializer
from rest_framework import serializers
from apps.Book.models import *
class BookSerializers(serializers.ModelSerializer):
    class Meta:
        model = BookModels
        fields = '__all__'
class BookAnotherUpDateSerializer(FlexFieldsModelSerializer):
    name = serializers.CharField(max_length=12, read_only=True)
    class Meta:
        model = BookAnother
        fields = '__all__'
        expandable_fields = {
            "BookModel": BookSerializers
        }
class BookAnotherSerializer(FlexFieldsModelSerializer):
    class Meta:
        model = BookAnother
        fields = '__all__'
        expandable_fields = {
            "BookModel": BookSerializers
        }

其他的不用修改

运行结果

http://127.0.0.1:8000/api/BookAnother/1/

http://127.0.0.1:8000/api/BookAnother/1/?expand=BookModel

安全优化

我们现在修改一下

# -*- coding: utf-8 -*-
# @Time    : 2021/2/9 下午3:09
# @Author  : void bug
# @FileName: Serializer.py
# @Software: PyCharm
from rest_flex_fields import FlexFieldsModelSerializer
from rest_framework import serializers
from apps.Book.models import *
class BookSerializers(serializers.ModelSerializer):
    class Meta:
        model = BookModels
        fields = '__all__'
class BookReadOnlySerializer(serializers.ModelSerializer):
    Isbn_Card = serializers.CharField(read_only=True)
    Book_Name = serializers.CharField(read_only=True)
    Book_author = serializers.CharField(read_only=True)
    Book_press = serializers.CharField(read_only=True)
    Book_stock = serializers.IntegerField(read_only=True)
    Book_notes = serializers.CharField(read_only=True)
    Price = serializers.DecimalField(read_only=True, max_digits=10000, decimal_places=2)
    class Meta:
        model = BookModels
        fields = '__all__'
class BookAnotherUpDateSerializer(FlexFieldsModelSerializer):
    name = serializers.CharField(max_length=12, read_only=True)
    class Meta:
        model = BookAnother
        fields = '__all__'
        expandable_fields = {
            "BookModel": BookReadOnlySerializer
        }
class BookAnotherSerializer(FlexFieldsModelSerializer):
    class Meta:
        model = BookAnother
        fields = '__all__'
        expandable_fields = {
            "BookModel": BookSerializers
        }

运行结果