Rest-framework框架的基本组件
快速实例：
序列化类
开发我们的Web API的第一件事是为我们的Web API提供一种将代码片段实例序列化和反序列化为诸如
json之类的表示形式的方式。我们可以通过声明与Django forms非常相似的序列化器（serializers）来实现。简单实用（基于django原生serializers基于CBV）
models.py
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from django.db import models
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class Book(models.Model):
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title = models.CharField(max_length=32)
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price = models.IntegerField()
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pub_date = models.DateField()
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publish = models.ForeignKey("Publish", on_delete=models.CASCADE)
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authors = models.ManyToManyField("Author")
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def __str__(self):
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return self.title
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class Publish(models.Model):
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name = models.CharField(max_length=32)
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email = models.EmailField()
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def __str__(self):
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return self.name
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class Author(models.Model):
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name = models.CharField(max_length=32)
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age = models.IntegerField()
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def __str__(self):
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return self.name
方式一：
分发url
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...
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path('publishes/', views.PublishesView.as_view()),
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...
视图类
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import json
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from django.shortcuts import render, HttpResponse
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from django.views import View
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from django.forms.models import model_to_dict
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from .models import *
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class PublishesView(View):
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# Publish.objects.all().values("name", "email"）
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# <QuerySet [{'name': '苹果出版社', 'email': '123@qq.com'}, {'name': '橘子出版社', 'email': '234@qq.com'}]>
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# list(Publish.objects.all().values("name", "email"))
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# [{'name': '苹果出版社', 'email': '123@qq.com'}, {'name': '橘子出版社', 'email': '234@qq.com'}]
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def get(self, request):
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# 序列化方式一
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# publish_list = list(Publish.objects.all().values("name", "email")) # 注意这个list()
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# return HttpResponse(json.dumps(publish_list))
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# 序列化方式二
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# 使用model_to_dict(obj)
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# publish_list = Publish.objects.all()
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# temp = []
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# for obj in publish_list: # 每一个obj就是类对象
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"""
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temp.append({
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"name": "obj.name",
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"email": "obj.email"
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})
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"""
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# temp.append(model_to_dict(obj))
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# return HttpResponse(json.dumps(temp))
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# 序列化方式三
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# publish_list = Publish.objects.all()
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# from django.core import serializers
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# ret = serializers.serialize('json', publish_list)
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# return HttpResponse(ret)
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采用restframework
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def post(self, request):
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pass
得到数据
model_to_dict(obj) {'id': 1, 'name': '苹果出版社'， ‘email’: '123@qq.com'}
使用rest_framework来序列化
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from rest_framework import serializers
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from rest_framework.response import Response
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from rest_framework.views import APIView
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# 为queryset做序列化
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class PublishSerializers(serializers.Serializer):
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"""等同于form.Form"""
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name = serializers.CharField()
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email = serializers.CharField()
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class PublishesView(APIView):
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def get(self, request):
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publish_list = Publish.objects.all()
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ps = PublishSerializers(publish_list, many=True) # 即可接收Queryset 也可接收 model_obj
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return Response(ps.data)
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def post(self, request):
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pass
得到的结果在页面中不会显示，会在postmen中显示
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[
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{
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"name": "苹果出版社",
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"email": "123@qq.com"
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},
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{
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"name": "橘子出版社",
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"email": "234@qq.com"
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}
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]
解析器request类
django的request类和rest-framework的request类的源码解析
依然是上面的代码 用postmen发送一次post请求
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class PublishesView(View):
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def post(self, request):
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print("POST", request.POST)
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print("BODY", request.body)
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return HttpResponse("POST")
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>>>POST <QueryDict: {'a': ['1'], 'b': ['2']}>
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[18/Oct/2018 16:19:02] "POST /publishes/ HTTP/1.1" 200 4
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BODY b'a=1&b=2'
这个过程里面到底发生了什么？
这个过程其实就是一次Django的请求周期
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# request 源码的入口
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from django.core.handlers.wsgi import WSGIRequest
rest_framework下面的APIview
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from rest_framework.views import APIView
OK reas_framework request 请求的取值问题
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from rest_framework.response import Response
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from rest_framework.views import APIView
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class PublishesView(APIView):
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def post(self, request):
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# 原生的request支持的操作
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# print("POST", request.POST)
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# print("BODY", request.body)
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return Response("POST")
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from rest_framework import serializers
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from rest_framework.response import Response
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from rest_framework.views import APIView
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# 为queryset做序列化
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class BookSerializers(serializers.Serializer):
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"""Book表是一个比较复杂的表包含了一对多与多对多"""
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title = serializers.CharField()
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price = serializers.IntegerField()
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pub_date = serializers.DateField()
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# 这怎么办？
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# publish = models.ForeignKey("Publish", on_delete=models.CASCADE) # 一对多
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# authors = models.ManyToManyField("Author") # 多对多
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publish = serializers.CharField(source="publish.name") # 一对多、类名小写
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# 多对多的话这个sourse不好使，得到的是Queryset
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authors = serializers.CharField(source="authors.all") # 多对多、类名小写.all() 自动执行
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class BookView(APIView):
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def get(self, request):
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book_list = Book.objects.all()
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bs = BookSerializers(book_list, many=True)
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return Response(bs.data)
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def post(self, request):
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pass
Postmen中的数据
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[
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{
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"title": "你好,再见",
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"price": 99,
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"pub_date": null,
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"publish": "苹果出版社",
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"authors": "<QuerySet [<Author: pontoon>, <Author: toonpon>]>" # 得到一个QuerySet
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},
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{
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"title": "再见,你好",
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"price": 88,
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"pub_date": null,
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"publish": "橘子出版社",
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"authors": "<QuerySet [<Author: pontoon>]>"
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},
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{
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"title": "谁动了我的奶酪？",
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"price": 77,
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"pub_date": null,
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"publish": "苹果出版社",
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"authors": "<QuerySet []>"
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}
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]
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# 为queryset做序列化
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class BookSerializers(serializers.Serializer):
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"""Book表是一个比较复杂的表包含了一对多与多对多"""
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title = serializers.CharField()
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price = serializers.IntegerField()
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pub_date = serializers.DateField()
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# 这怎么办？
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# publish = models.ForeignKey("Publish", on_delete=models.CASCADE) # 一对多
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# authors = models.ManyToManyField("Author") # 多对多
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publish = serializers.CharField(source="publish.name") # 一对多、类名小写
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# 多对多的话这个sourse不好使，得到的是Queryset
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# authors = serializers.CharField(source="authors.all") # 多对多、类名小写.all() 自动执行
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# 多对多这样来整
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authors = serializers.SerializerMethodField()
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def get_authors(self, obj):
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temp = []
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for obj in obj.authors.all():
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temp.append(obj.name)
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return temp
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class BookView(APIView):
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def get(self, request):
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book_list = Book.objects.all()
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bs = BookSerializers(book_list, many=True)
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return Response(bs.data)
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def post(self, request):
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pass
Postmen
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[
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{
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"title": "你好,再见",
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"price": 99,
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"pub_date": null,
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"publish": "苹果出版社",
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"authors": [
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"pontoon",
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"toonpon"
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]
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},
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{
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"title": "再见,你好",
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"price": 88,
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"pub_date": null,
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"publish": "橘子出版社",
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"authors": [
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"pontoon"
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]
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},
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{
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"title": "谁动了我的奶酪？",
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"price": 77,
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"pub_date": null,
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"publish": "苹果出版社",
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"authors": []
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}
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]
这样的数据就比较好
ModelSerialezer
POST请求的数据
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# 为queryset做序列化
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class BookSerializers(serializers.Serializer):
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"""Book表是一个比较复杂的表包含了一对多与多对多"""
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title = serializers.CharField()
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price = serializers.IntegerField()
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pub_date = serializers.DateField()
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# 这怎么办？
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# publish = models.ForeignKey("Publish", on_delete=models.CASCADE) # 一对多
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# authors = models.ManyToManyField("Author") # 多对多
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publish = serializers.CharField(source="publish.pk") # 一对多、类名小写
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# 多对多的话这个sourse不好使，得到的是Queryset
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# authors = serializers.CharField(source="authors.all") # 多对多、类名小写.all() 自动执行
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# 多对多这样来整
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authors = serializers.SerializerMethodField()
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def get_authors(self, obj):
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temp = []
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for obj in obj.authors.all():
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temp.append(obj)
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return temp
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# 这个地方我们对字段进行了一些列的定制
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class BookView(APIView):
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def get(self, request):
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...
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def post(self, request):
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bs = BookSerializers(data=request.data)
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if bs.is_valid(): # 验证码提交过来的数据是否合格
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print(bs.validated_data) # 如果是合格的数据走了内置的create()方法，将提交过来的保存至数据库中！
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bs.save() # 保存
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return Response(bs.data) # 返回数据
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else:
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return Response(bs.errors) # 返回错误
用postmen传数据过来会报错
该咋整，如何将数据保存至数据库中咧？
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class BookSerializers(serializers.ModelSerializer):
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"""Book表是一个比较复杂的表包含了一对多与多对多"""
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class Meta:
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model = Book
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fields = "__all__"
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publish = serializers.CharField(source="publish.pk") # 一对多、类名小写
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def create(self, validated_data):
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"""重写源码中的create方法"""
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print("validated_data", validated_data)
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book = Book.objects.create(title=validated_data["title"],
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price=validated_data['price'],
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publish_id=validated_data['publish']['pk'],
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)
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book.authors.add(*validated_data["authors"])
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return book
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>>> validated_data {'publish': {'pk': '1'}, 'title': 'java', 'price': 20, 'authors': [<Author: pontoon>, <Author: toonpon>]}
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class BookView(APIView):
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def get(self, request):
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book_list = Book.objects.all()
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bs = BookSerializers(book_list, many=True)
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return Response(bs.data)
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def post(self, request):
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bs = BookSerializers(data=request.data)
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if bs.is_valid():
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bs.save()
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return Response(bs.data)
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else:
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return Response(bs.errors)
Postmen在次提交数据
返回成功啦！ ，不过这也太吉儿的复杂了把，还得花时间整理！透~
单条数据的get/post请求
url
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# 获取所有数据的URL
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path('books/', views.BookView.as_view()),
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# 获取单条数据的URL
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path('books/<int:pk>', views.BookDetailView.as_view()),
视图
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class BookDetailView(APIView):
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"""获取单条数据"""
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def get(self, request, pk):
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book = Book.objects.get(pk=pk)
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bs = BookModelSerializers(book)
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return Response(bs.data)
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def put(self, request, pk):
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""" 想那张表提交那条数据 """
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book = Book.objects.get(pk=pk)
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bs = BookModelSerializers(book, data=request.data)
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if bs.is_valid():
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bs.save()
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return Response(bs.errors)
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def delete(self, request, pk):
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Book.objects.get(pk=pk).delete()
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return Response()
序列化超链接字段
第二步
效果如图
