序列化器与视图

from rest_framework import serializers

from .models import BookInfo, HeroInfo


class BookInfoModelSerializer(serializers.ModelSerializer):
    """BookInfo模型类的序列化器"""

    class Meta:
        model = BookInfo
        # fields = '__all__'
        # fields = ['id', 'btitle', 'bpub_date']
        # exclude = ('image',)
        fields = ('id', 'btitle', 'bpub_date', 'bread', 'bcomment')
        extra_kwargs = {
            'bread': {'min_value': 0, 'required': True},
            'bcomment': {'min_value': 0, 'required': True},
        }


class HeroInfoModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = HeroInfo
        fields = ['id', 'hname', 'hbook']
        depth = 1


def about_django(value):
    if 'django' not in value.lower():
        raise serializers.ValidationError("图书不是关于Django的")


class BookInfoSerializer(serializers.Serializer):
    """图书数据序列化器"""
    id = serializers.IntegerField(label='ID', read_only=True)
    btitle = serializers.CharField(label='名称', max_length=20, validators=[about_django])
    bpub_date = serializers.DateField(label='发布日期', required=False)
    bread = serializers.IntegerField(label='阅读量', required=False)
    bcomment = serializers.IntegerField(label='评论量', required=False)
    image = serializers.ImageField(label='图片', required=False)
    heroinfo_set = serializers.PrimaryKeyRelatedField(read_only=True, many=True)  # 新增

    def validate_btitle(self, value):
        """单个字段验证"""
        if 'django' not in value.lower():
            raise serializers.ValidationError("图书不是关于Django的")
        return value

    def validate(self, attrs):
        """多字段联合验证"""
        bread = attrs['bread']
        bcomment = attrs['bcomment']
        if bread < bcomment:
            raise serializers.ValidationError('阅读量小于评论量')
        return attrs

    def create(self, validated_data):
        """新建"""
        return BookInfo.objects.create(**validated_data)

    def update(self, instance, validated_data):
        """更新，instance为要更新的对象实例"""
        instance.btitle = validated_data.get('btitle', instance.btitle)
        instance.bpub_date = validated_data.get('bpub_date', instance.bpub_date)
        instance.bread = validated_data.get('bread', instance.bread)
        instance.bcomment = validated_data.get('bcomment', instance.bcomment)
        instance.save()
        return instance


class HeroInfoSerializer(serializers.Serializer):
    """英雄数据序列化器"""
    GENDER_CHOICES = (
        (0, 'male'),
        (1, 'female')
    )
    id = serializers.IntegerField(label='ID', read_only=True)
    hname = serializers.CharField(label='名字', max_length=20)
    hgender = serializers.ChoiceField(choices=GENDER_CHOICES, label='性别', required=False)
    hcomment = serializers.CharField(label='描述信息', max_length=200, required=False, allow_null=True)
    hbook = serializers.PrimaryKeyRelatedField(label='图书', read_only=True)

from django.shortcuts import render
from django.views.generic import View
from django.http import JsonResponse, HttpResponse
import json
from datetime import datetime
from rest_framework.viewsets import ModelViewSet

from .models import BookInfo
from . import serializers
# Create your views here.


"""
GET     /books/         提供所有记录
POST    /books/         新增一条记录
GET     /books/<pk>/    提供指定id的记录
PUT     /books/<pk>     修改指定id的记录
DELETE  /books/<pk>/    删除指定id的记录

响应数据    JSON
"""


class BookInfoViewSet(ModelViewSet):
    """使用DRF实现增删改查的后端API"""

    # 指定查询集
    queryset = BookInfo.objects.all()
    # 指定序列化器
    serializer_class = serializers.BookInfoSerializer


class BooksAPIView(View):

    def get(self, request):
        """提供所有记录
        GET     /books/
        """
        # 查询所有记录 books = [BookInfo,BookInfo,BookInfo,BookInfo,BookInfo]
        books = BookInfo.objects.all()

        # 将模型列表转成字典列表
        book_list = []
        for book in books:
            book_list.append({
                'id': book.id,
                'btitle': book.btitle,
                'bpub_date': book.bpub_date,
                'bread': book.bread,
                'bcomment': book.bcomment,
                'image': book.image.url if book.image else ''
            })

        # 响应JSON数据
        return JsonResponse(book_list, safe=False)


    def post(self, request):
        """新增一条记录
        POST    /books/
        """
        # 读取客户端传入的JSON数据
        json_bytes = request.body
        json_str = json_bytes.decode()
        book_dict = json.loads(json_str)

        # 创建新的记录
        book = BookInfo.objects.create(
            btitle=book_dict.get('btitle'),
            bpub_date=datetime.strptime(book_dict.get('bpub_date'), '%Y-%m-%d').date(),
            bread = book_dict['bread'],
            bcomment = book_dict['bcomment']
        )

        # 构造响应数据
        response_book_dict = {
            'id': book.id,
            'btitle': book.btitle,
            'bpub_date': book.bpub_date,
            'bread': book.bread,
            'bcomment': book.bcomment,
            'image': book.image.url if book.image else ''
        }

        # 响应结果
        return JsonResponse(response_book_dict, status=201)


class BookAPIView(View):

    def get(self, request, pk):
        """提供指定id的记录
        GET     /books/<pk>/
        """
        # 判断pk是否合法
        try:
            book = BookInfo.objects.get(id=pk)
        except BookInfo.DoesNotExist:
            return HttpResponse(status=404)

        # 构造响应数据
        response_book_dict = {
            'id': book.id,
            'btitle': book.btitle,
            'bpub_date': book.bpub_date,
            'bread': book.bread,
            'bcomment': book.bcomment,
            'image': book.image.url if book.image else ''
        }

        # 响应结果
        return JsonResponse(response_book_dict)


    def put(self, request, pk):
        """修改指定id的记录
        PUT     /books/<pk>
        """
        # 判断pk是否合法
        try:
            book = BookInfo.objects.get(id=pk)
        except BookInfo.DoesNotExist:
            return HttpResponse(status=404)

        # 读取客户端传入的JSON数据
        json_bytes = request.body
        json_str = json_bytes.decode()
        book_dict = json.loads(json_str)

        # 修改记录
        book.btitle = book_dict.get('btitle')
        book.save()

        # 构造响应数据
        response_book_dict = {
            'id': book.id,
            'btitle': book.btitle,
            'bpub_date': book.bpub_date,
            'bread': book.bread,
            'bcomment': book.bcomment,
            'image': book.image.url if book.image else ''
        }

        # 响应结果
        return JsonResponse(response_book_dict)


    def delete(self, request, pk):
        """删除指定id的记录
        DELETE  /books/<pk>/    
        """
        # 判断pk是否合法
        try:
            book = BookInfo.objects.get(id=pk)
        except BookInfo.DoesNotExist:
            return HttpResponse(status=404)

        # 删除
        book.delete()

        # 响应
        return HttpResponse(status=204)