DRF 简单使用（详细注释版）

1.djangorestframework使用

1. 下载安装

pip install djangorestframework  ## djangorestframework
pip install django-filter  ## 过滤使用

1. 注册

INSTALLED_APPS = [
    ...
    'rest_framework',
    'django_filters'
]

1. model

class Feedback(models.Model):
    type_choice = (
        (0, '未分类'),
        (1, '学习笔记'),
        (2, '学员评价'),
        (3, '入职邀约'),
    )

    img = models.ImageField(upload_to='img/feedback/')
    back_type = models.IntegerField(choices=type_choice, default=0)

1. 路由

url(r'^ajax_feedback/', views.AjaxFeedback.as_view()),

1. 视图

from rest_framework import generics
from web.serializers import FeedbackSerializer
from web.pagination import DefaultPagination
from django_filters.rest_framework import DjangoFilterBackend


class AjaxFeedback(generics.ListAPIView):
    queryset = models.Feedback.objects.all()
    serializer_class = FeedbackSerializer
    pagination_class = DefaultPagination
    filter_backends = [DjangoFilterBackend, ]
    filter_fields = ['back_type']

1. 序列化器类

from rest_framework import serializers
from repository import models


class FeedbackSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Feedback
        fields = ['img']

1. 分页类

from rest_framework.pagination import PageNumberPagination

class DefaultPagination(PageNumberPagination):
    page_size = 8  # 一页多少条数据
    page_query_param = 'page'  # 分页查询条件的key
    page_size_query_param = 'size'
    # max_page_size = 8

2.序列化器serializer

序列化: 将对象,字符串等数据类型转化为可用于传输/存储的数据形式

• -----serializer文件-----

from rest_framework import serializers
from app01 import models

# 获取外键名称
class PublisherSerializer(serializers.Serializer):
    name = serializers.CharField()

# 1.自定义序列化器获取manytomany外键名称
class AuthorSerializer(serializers.Serializer):
    id = serializers.IntegerField()
    name = serializers.CharField()


class BookSerializer(serializers.Serializer):
    # 要序列化的书籍参数
    title = serializers.CharField()
    price = serializers.DecimalField(max_digits=6, decimal_places=2)
    pub_date = serializers.DateTimeField()
    # 仅仅在get需要的字段
    pub = PublisherSerializer(required=False, read_only=True) # 获取外键字段名称,自定义序列化器
    authors = serializers.SerializerMethodField(read_only=True)  # 获取多对多字段名称 1.自定义序列化器 2.自定义 get_字段名字段名
    
    # 仅仅在post需要的字段
    post_pub = serializers.IntegerField(write_only=True)
    post_author = serializers.ListField(write_only=True)
    
     # 2.自定义 get_字段名
    def get_authors(self, obj): # obj是书籍对象
        ser_obj = AuthorSerializer(obj.authors.all(), many=True)
        return ser_obj.data
    
    
    # 新建数据写入数据库时自定义create方法
    def create(self, validated_data):# validated_data校验过的数据
        # 写入数据
        book_obj = models.Book.objects.create(
            title=validated_data['title'],
            price=validated_data['price'],
            pub_date=validated_data['pub_date'],
            pub_id=validated_data['post_pub']
        )
        book_obj.authors.set(validated_data['post_author'])
        return book_obj
    
    
    # put方法执行到save方法是,执行update
    def update(self, instance, validated_data):
        instance.title = validated_data.get('title',instance.title)# 使用get请求方法防止在部分修改数据时报错
        instance.price = validated_data.get('price',instance.price)
        instance.pub_date = validated_data.get('pub_date',instance.pub_date)
        instance.pub_id = validated_data.get('post_pub',instance.pub_id)
        instance.save()
        instance.authors.set(validated_data.get('post_authors',instance.authors.all()))
        return instance

• -----view文件-----

from app_rest import models

from rest_framework.views import APIView
from rest_framework.response import Response  # rest_framework返回对象
from app_rest.serializer import BookSerializer


class BookList(APIView):
    """查询新增"""

    # 获取数据
    def get(self, request, *args, **kwargs):
        all_books = models.Book.objects.all()
        ser_data = BookSerializer(all_books, many=True)  # many=True可以加入一个对象列表,单个对象不需要加入many参数
        return Response(ser_data.data)

    # 提交数据
    def post(self, request, *args, **kwargs):
        ser_obj = BookSerializer(data=request.data)
        if ser_obj.is_valid():
            ser_obj.save()
            return Response(ser_obj.data)
        return Response(ser_obj.errors)


class BookView(APIView):
    """修改删除"""

    def get(self, request, pk, *args, **kwargs):
        """查询到要修改的数据"""
        book_obj = models.Book.objects.filter(pk=pk).first()
        ser_obj = BookSerializer(instance=book_obj)
        return Response(ser_obj.data)

    def put(self, request, pk, *args, **kwargs):
        """
        提交要修改的数据
        :return:
        """
        book_obj = models.Book.objects.filter(pk=pk).first()
        ser_obj = BookSerializer(instance=book_obj, data=request.data, partial=True)  # partial=True 允许部分修改
        if ser_obj.is_valid():
            ser_obj.save()
            return Response(ser_obj.data)
        return Response(ser_obj.errors)

    def delete(self, request, pk, *args, **kwargs):
        """删除"""
        obj = models.Book.objects.filter(pk=pk).first()
        if obj:
            obj.delete()
            return Response({'msg': '删除成功'})
        return Response({'error': '数据不存在'})

• ---data.json---需要数据结构

  {
    "title": "桃花侠大战菊花怪1",
    "price": "111.11",
    "pub_date": "2019-01-01T10:10:10Z",
    "post_pub": 1,
    "post_author": [
      1,
      2
    ]
  }

3. 序列化器钩子

• 自定义校验器

  from rest_framework import serializers
  
  def validate_title(value):
      if '苍老师' in value:
          raise serializers.ValidationError
      return value
  
  class BookSerializer(serializers.Serializer):
      # 要序列化的书籍参数
      title = serializers.CharField(validators=[])

• 局部钩子与全局钩子

  class BookSerializer(serializers.Serializer):
      title = serializers.CharField()
      price = serializers.DecimalField(max_digits=6, decimal_places=2)
      pub_date = serializers.DateTimeField()
    # 仅仅在get需要的字段
      pub = PublisherSerializer(required=False, read_only=True) # 获取外键字段名称,自定义序列化器
      authors = serializers.SerializerMethodField(read_only=True)  # 获取多对多字段名称 1.自定义序列化器 2.自定义 get_字段名字段名
  
    # 仅仅在post需要的字段
      post_pub = serializers.IntegerField(write_only=True)
      post_author = serializers.ListField(write_only=True)
  
       # 2.自定义 get_字段名
      def get_authors(self, obj): # obj是书籍对象
          ser_obj = AuthorSerializer(obj.authors.all(), many=True)
          return ser_obj.data
  
  
      # 局部钩子
      def validate_title(self,value):
          if '苍老师' in value:
              raise serializers.ValidationError
          return value
  
      # 全局钩子
      def validate(self,attrs):
          if '苍老师' in attrs:
              raise serializers.ValidationError
        return attrs
  

4.modelserializer

from rest_framework import serializers

# 获取外键名称
class PublisherSerializer(serializers.Serializer):
    name = serializers.CharField()

# 1.自定义序列化器获取manytomany外键名称
class AuthorSerializer(serializers.Serializer):
    id = serializers.IntegerField()
    name = serializers.CharField()



# 显示字段
class BookSerializer(serializers.modelSerializer):
    
    # 显示外键以及多对多字段的name
    pub_info = serializers.SerializerMethodField(read_only = True )
    authors_info = serializers.SerializerMethodField(read_only = True )
    
    def get_pub_info(self,obj):
        return PublisherSerializer(obj,pub).data
    
    def get_authors_info(self,obj):
        return AuthorSerializer(obj,author.all(),many = True).data
    
    
    class Meta:
        model = models.Book
        fields = '__all__'
        
        #给字段加限制
        extra_kwargs = {
            'pub':{'write_only':True},
            'authors':{'write_only':True}
        }