DRF之RESTful規範(一)

web接口

# 請求工具：postman => https://www.getpostman.com/

# 接口：url鏈接，通過向鏈接發生不同的類型請求與數據得到相應的響應數據

# http://127.0.0.1:8888/test/
# https://api.map.baidu.com/place/v2/search
'''
ak: 6E823f587c95f0148c19993539b99295
region: 上海
query: 肯德基
output: json
'''

RESTful規範

# REST: 表徵性狀態轉移(Representational State Transfer)
# RESTful規範：web數據請求接口設計規範

'''
1）通常使用https請求
2）域名：有api關鍵字出現
	-- https://api.example.com  (存在跨域問題)
	-- https://example.com/api
3）版本：不同版本需要標註
	-- https://example.com/api/v1 | -- https://example.com/api/1
	-- https://example.com/api/v2 | -- https://example.com/api/2
4）資源：請求的目標數據稱之爲資源，資源一般都有名詞複數表示
	-- https://example.com/api/v1/books  (之前不規範的案例: /get_books/)
5）操作方式：不從請求鏈接體現操作方式，從請求方式上決定操作方式
	-- get：https://example.com/api/v1/books  獲取所有
	-- post：https://example.com/api/v1/books  新增一本
	-- put：https://example.com/api/v1/book/1  更新id=1的一本
	-- patch：https://example.com/api/v1/book/1  更新id=1的一本
	-- delete：https://example.com/api/v1/book/1  刪除id=1的一本
6）資源過濾：通過接口傳遞參數來過濾資源
	-- https://example.com/api/v1/books?limit=10  限制10條
7）狀態碼：返回數據要標準狀態碼，通過在數據中 {"status": 200}
	-- SUCCESS("0", "查詢成功")
	-- NODATA("1xx", "非正確，無數據，顯示基本信息")
	-- FEAILED("2xx", "查詢失敗")
8）錯誤信息：請求失敗需要標註錯誤信息  {"message": "請求參數不合法"}
9）操作結果：請求操作成功的返回結果 {"results": []}
	-- get：返回資源列表 | 返回單一資源
	-- post：返回單一新增資源
	-- put：返回更新的資源
	-- patch：返回更新的資源
	-- delete：返回空文檔
10）子資源返回資源接口：返回的資源如果有子資源，返回子資源的鏈接地址，如查找書，書的封面圖片就可以url表示
'''

drf簡易書寫TESTful規範接口

# 路由層
from app import views
urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^cbv/', views.CBVTest.as_view()),
    url(r'^books/', views.books),
    url(r'^book/(?P<id>\d+)/', views.book),
]

# 視圖層
from django.http import JsonResponse
book_list = [{'id': 1, 'name': '紅樓夢'}, {'id': 2, 'name': '水滸傳'}]
def books(request):
    if request.method == "GET":
        if 'ak' not in request.GET:
            return JsonResponse({
                'status': '101',
                'msg': 'ak不存在'
            }, json_dumps_params={'ensure_ascii': False})
        ak = request.GET.get('ak')
        if ak != '123abc':
            return JsonResponse({
                'status': '200',
                'msg': 'ak非法'
            }, json_dumps_params={'ensure_ascii': False})
        return JsonResponse({
                'status': '0',
                'msg': 'ok',
                'results': book_list
            }, json_dumps_params={'ensure_ascii': False})
    if request.method == 'POST':
        name = request.POST.get('name')
        id = len(book_list) + 1
        book = {'id': id, 'name': name}
        book_list.append(book)
        return JsonResponse({
            'status': '0',
            'msg': 'ok',
            'results': book
        }, json_dumps_params={'ensure_ascii': False})

CBV源碼分析

# 視圖層
from django.shortcuts import render, HttpResponse
from django.views import View
class CBVTest(View):
    # 通過調度(dispatch)分發請求
    def dispatch(self, request, *args, **kwargs):
        pass
        super().dispatch(request, *args, **kwargs)
        pass

    def get(self, request):
        return render(request, 'cbv.html')

    def post(self, request):
        return HttpResponse('cbv post method')

<!-- 模板層 -->
<form action="/cbv/" method="post">
    {% csrf_token %}
    <input type="text" name="usr">
    <button type="submit">提交</button>
</form>

# 路由層
from app import views
urlpatterns = [
    url(r'^cbv/', views.CBVTest.as_view()),
]

drf安裝與使用

# 1）安裝drf：pip3 install djangorestframework
# 2）settings.py註冊app：INSTALLED_APPS = [..., 'rest_framework']
# 3）基於cbv完成滿足RSSTful規範的接口

# 視圖層
from rest_framework.views import APIView
from rest_framework.response import Response
user_list = [{'id': 1, 'name': 'Bob'}, {'id': 2, 'name': 'Tom'}]
class Users(APIView):
    def get(self, request, *args, **kwargs):
        return Response({
            'status': 0,
            'msg': 'ok',
            'results': user_list
        })
    def post(self, request, *args, **kwargs):
        # request對formdata，urlencoded，json三個格式參數均能解析
        name = request.data.get('name')
        id = len(user_list) + 1
        user = {'id': id, 'name': name}
        user_list.append(user)
        return Response({
            'status': '0',
            'msg': 'ok',
            'results': user
        })

# 路由層
from app import views
urlpatterns = [
    url(r'^users/', views.Users.as_view()),
]

request源碼分析

# as_view()
	# 核心走了父類as_view
	view = super(APIView, cls).as_view(**initkwargs)
    # 返回的是局部禁用csrf認證的view視圖函數
    return csrf_exempt(view)
    
# dispatch(self, request, *args, **kwargs)
	# 二次封裝request對象
	request = self.initialize_request(request, *args, **kwargs)
    # 自定義request規則
    self.initial(request, *args, **kwargs)
    
# initialize_request(self, request, *args, **kwargs)
	# 原生request封裝在request._request
    
# initial(self, request, *args, **kwargs)
	# 認證
	self.perform_authentication(request)
    # 權限
    self.check_permissions(request)
    # 頻率
    self.check_throttles(request)

drf序列化

初級

# models.py
class Students(models.Model):
    name = models.CharField(max_length=32)
    age = models.IntegerField()
    gender = models.CharField(max_length=8)
    def __str__(self):
        return 'Student: %s' % self.name
    

# 自定義序列化類：爲具體的類提供序列化
# my_serializer.py
from rest_framework import serializers
class StudentSerializer(serializers.Serializer):
    id = serializers.IntegerField()
    name = serializers.CharField()
    age = serializers.IntegerField()
    gender = serializers.CharField()
    

# views.py
from app import models
from app.my_serializer import StudentSerializer
class Students(APIView):
    def get(self, request, *args, **kwargs):
        stus = models.Students.objects.all()
        # 需要序列化多個對象，需要明確many=True
        stu_ser = StudentSerializer(stus, many=True)
        print(stus)
        return Response({
            'status': 0,
            'msg': 'ok',
            'results': stu_ser.data
        })
    
    
# urls.py
from app import views
urlpatterns = [
    url(r'^students/', views.Students.as_view()),
]