6 功能开发

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1.发布

1.1 小程序

• 选图片

• 填内容

• 提交

  {cover:"https://mini-1251317460.cos.ap-chengdu.myqcloud.com/08a9daei1578736867828.png",content:"小程序开发太简单了",address:"北京市",topic:1,images:["https://mini-1251317460.cos.ap-chengdu.myqcloud.com/08a9daei1578736867828.png","https://mini-1251317460.cos.ap-chengdu.myqcloud.com/08a9daei1578736867828.png"]
  }
  

  {cover:"https://mini-1251317460.cos.ap-chengdu.myqcloud.com/08a9daei1578736867828.png",content:"小程序开发太简单了",address:"北京市",topic:1,images:[{path:"https://mini-1251317460.cos.ap-chengdu.myqcloud.com/08a9daei1578736867828.png",cos_key:"08a9daei1578736867828.pn"},{path:"https://mini-1251317460.cos.ap-chengdu.myqcloud.com/08a9daei1578736867828.png",cos_key:"08a9daei1578736867828.pn"},]
  }
  

1.2 API

from rest_framework.views import APIView
from rest_framework.generics import CreateAPIView
from rest_framework import serializers
from apps.api import models
class NewsDetailModelSerializer(serializers.Serializer):key = serializers.CharField()cos_path = serializers.CharField()class NewsModelSerializer(serializers.ModelSerializer):images = NewsDetailModelSerializer(many=True)class Meta:model = models.Newsfields = "__all__"class NewsView(CreateAPIView):""" 创建动态的API """serializer_class = NewsModelSerializer

class News(models.Model):"""动态"""cover = models.CharField(verbose_name='封面', max_length=128)content = models.CharField(verbose_name='内容', max_length=255)topic = models.ForeignKey(verbose_name='话题', to='Topic', null=True, blank=True)address = models.CharField(verbose_name='位置', max_length=128, null=True, blank=True)user = models.ForeignKey(verbose_name='发布者', to='UserInfo', related_name='news')favor_count = models.PositiveIntegerField(verbose_name='赞数', default=0)viewer_count = models.PositiveIntegerField(verbose_name='浏览数', default=0)comment_count = models.PositiveIntegerField(verbose_name='评论数', default=0)create_date = models.DateTimeField(verbose_name='创建时间', auto_now_add=True)

class NewsDetail(models.Model):"""动态详细"""key = models.CharField(verbose_name='腾讯对象存储中的文件名', max_length=128, help_text="用于以后在腾讯对象存储中删除")cos_path = models.CharField(verbose_name='腾讯对象存储中图片路径', max_length=128)news = models.ForeignKey(verbose_name='动态', to='News')

1.3 规则

{k1:v1,k2:v2,k3:{...},k4:[{....}]
}

2.restful api回顾

2.1 APIView （ 可以 ）

from rest_framework.response import Response
class UserModelSerializer(serializers.ModelSerializer):class Meta:model = models.UserInfofields = "__all__"class UserView(APIView):def get(self,request,*args,**kwargs):user_list = models.UserInfo.objects.all()ser = UserModelSerializer(instance=user_list,many=True)return Response(ser.data)def post(self,request,*args,**kwargs):ser = UserModelSerializer(data=request.data)if ser.is_valid():# models.UserInfo.objects.create(**ser.validated_data)ser.save(user_id=1)return Response(ser.data)return Response(ser.errors)

2.2 ListAPIView

ListAPIView,CreateAPIView,RetrieveAPIView,UpdateAPIView,DestroyAPIView

class NewTestModelSerializer(serializers.ModelSerializer):class Meta:model = models.Newsfields = "__all__"class NewTestView(CreateAPIView,ListAPIView):serializer_class = NewTestModelSerializerqueryset = models.News.objects.filter(id__gt=4)

2.2.1 用户传递某些值

创建用户时，自己在后台生成一个UID。

class NewTestModelSerializer(serializers.ModelSerializer):class Meta:model = models.Newsfields = "__all__"class NewTestView(CreateAPIView,ListAPIView):serializer_class = NewTestModelSerializerqueryset = models.News.objects.filter(id__gt=4)def perform_create(self, serializer):serializer.save(uid=str(uuid.uuid4()))

2.2.2 fields和exclude的区别？

通过fields和exclude定制页面展示数据。

需求：只显示用户表的id,name,age的数据，其他不显示。

class NewTestModelSerializer(serializers.ModelSerializer):class Meta:model = models.News# fields = ["id","name",'age']# fields = "__all__"exclude = ['gender']class NewTestView(ListAPIView):serializer_class = NewTestModelSerializerqueryset = models.User.objects.all()[{id:1,name:'xxx',age:18},{id:1,name:'xxx',age:11},{id:1,name:'xxx',age:99},
]

需求：数据库有5个字段，显示7个字段。

class NewTestModelSerializer(serializers.ModelSerializer):xx = serializers.CharField(source='id')x1 = serializers.SerializerMethodField()class Meta:model = models.News# fields = "__all__"# fields = ['id','name','age','gender','phone','xx','x1']exclude = ['id','name']def get_x1(self,obj):return obj.idclass NewTestView(ListAPIView):serializer_class = NewTestModelSerializerqueryset = models.User.objects.all()[{id:1,name:'xxx',age:18...   xx:1,x1:1},{id:2,name:'xxx',age:11...   xx:2,x1:2},{id:3,name:'xxx',age:99,     xx:3,x1:3},
]

2.2.3 read_only

添加时不要，查看时候需要。

需求：编写两个接口 添加（3字段）、获取列表（5个字段）

class NewTestModelSerializer(serializers.ModelSerializer):# phone = serializers.CharField(source='phone',read_only=True)# email = serializers.CharField(source='email',read_only=True)class Meta:model = models.Newsfields = "__all__"read_only_fields = ['phone','email',]class NewTestView(CreateAPIView, ListAPIView):serializer_class = NewTestModelSerializerqueryset = models.User.objects.all()添加：{name:'xx',age:'19',gender:1}
获取：[{name:'xx',age:'xx',gender:'',phone:'xx',email:xxx}]

2.3.4 复杂需求

添加时用一个serializers、列表时用一个serializers

class NewTestModelSerializer1(serializers.ModelSerializer):class Meta:model = models.Newsfields = "__all__"class NewTestModelSerializer2(serializers.ModelSerializer):class Meta:model = models.Newsfields = "__all__"class NewTestView(CreateAPIView, ListAPIView):queryset = models.User.objects.all()def get_serializer_class(self):if self.request.method == 'POST':return NewTestModelSerializer1if self.request.method == 'GET':return NewTestModelSerializer2

2.3.5 serializers嵌套

class CreateNewsTopicModelSerializer(serializers.Serializer):key = serializers.CharField()cos_path = serializers.CharField()class CreateNewsModelSerializer(serializers.ModelSerializer):imageList = CreateNewsTopicModelSerializer(many=True)class Meta:model = models.Newsexclude = ['user', 'viewer_count', 'comment_count',"favor_count"]def create(self, validated_data):# 把imageList切走image_list = validated_data.pop('imageList')# 创建New表中的数据news_object = models.News.objects.create(**validated_data)data_list = models.NewsDetail.objects.bulk_create([models.NewsDetail(**info, news=news_object) for info in image_list])news_object.imageList = data_listif news_object.topic:news_object.topic.count += 1news_object.save()return news_objectclass NewsView(CreateAPIView):"""发布动态"""serializer_class = CreateNewsModelSerializerdef perform_create(self, serializer):# 只能保存：News表中的数据（）# 调用serializer对象的save（先调用create）new_object = serializer.save(user_id=1)return new_object

3. 首页展示

• 小程序
  • 初始化
  • 下拉刷新
  • 上翻页
  • 瀑布流
• 后端API
  • APIView
  • ListAPIView
    • filter
    • pagination

扩展：分页的优化

记录最大值和最小值，防止切片全部数据扫描的问题。

4.详细页面（3点）

• 写脚本构造数据
• 最近的访客
• 一级评论