知識點

1. Restful API介紹
2. Django Restful Framework介紹
3. 實例學習

簡介

Rest

Rest(Representational State Transfer)表現層狀態轉化

是一種架構風格：

• 從資源角度來觀察整個網絡
• 每個URL代表一種資源
• 客戶端通過四個http動詞對后端進行操作

Http動詞

1. get 獲取資源
2. post 新建一個資源
3. put 更新資源
4. delete 刪除資源

Http動詞舉例

1. get /poems
2. post /poems
3. get poems/id
4. put poems/id
5. delete poems/id

狀態碼

服務器向客戶端返回的狀態碼和信息提示：
200 OK - [GET]：服務器成功返回用戶請求的數據
201 CREATED - [POST/PUT]：用戶新建或修改數據成功。
400 INVALID REQUEST - [POST/PUT]：用戶發出的請求有錯誤
更多可以參考：10 Status Code Definitions

Django REST framework

一套構建restful API有效和便利的框架
安裝：pip install djangorestframework

參考文檔

Django REST framework的各種技巧【目錄索引】
代碼地址：Spareibs的Github

實驗操作

簡單實現Pome的get方法和post方法

定義一個serializers.ModelSerializer的子類并設置元數據 【serializers.py】

from rest_framework import serializers
from .models import Poem


class PoemSerializer(serializers.ModelSerializer):
    class Meta:
        # 制定元數據的model和fields
        model = Poem
        fields = ['author', 'title', 'type']

定義視圖函數的操作【views.py】

from rest_framework import status
from rest_framework.response import Response
from .serializers import PoemSerializer
from .models import Poem


class PoemListView(APIView):
    def get(self, request, format=None):
        poems = Poem.objects.all()
        serializer = PoemSerializer(poems, many=True)
        return Response(serializer.data)

    def post(self, request, format=None):
        serializer = PoemSerializer(data=request.data, many=True)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data, status=status.HTTP_201_CREATED)
        else:
            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

定義路由策略【urls.py】

from django.conf.urls import url
from . import views

urlpatterns = [
    url(r'^poems/$', views.PoemListView.as_view(), name="poem_list"),
]

使用裝飾器

定義視圖函數的操作【views.py】

@api_view(['GET', 'PUT', 'DELETE'])
def poem_detail(request, pk):
    try:
        poem = Poem.objects.get(pk=pk)
    except Poem.DoesNotExist:
        return Response(status=status.HTTP_404_NOT_FOUND)

    if request.method == 'GET':
        serializer = PoemSerializer(poem)
        return Response(serializer.data)
    elif request.method == 'PUT':
        serializer = PoemSerializer(Poem, request.data)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data)
        else:
            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
    elif request.method == 'DELETE':
        poem.delete()
        return Response(status=status.HTTP_204_NO_CONTENT)

定義路由策略【urls.py】

from django.conf.urls import url
from . import views

urlpatterns = [
    url(r'^poem/(?P<pk>[0-9]+)$', views.poem_detail, name="poem_list"),
]