APIView和View的區別

前言

django中編輯視圖views.py有兩種方式，一種是基於類的實現，另外一種是函數式的實現方式，兩種方法都可以用。
REST框架提供了一個APIView類，它是Django View類的子類。

View與APIView的區別

View是Django默認的視圖基類，APIView是REST framework提供的所有視圖的基類, 繼承自Django的View。

APIView與View的不同之處在於：

• 傳入到視圖方法中的是REST framework的Request對象，而不是Django的HttpRequeset對象；
• 視圖方法可以返回REST framework的Response對象，視圖會為響應數據設置（render）符合前端要求的格式；
• 任何APIException異常都會被捕獲到，並且處理成合適的響應信息；APIException異常捕獲
• 在進行dispatch()分發前，會對請求進行身份認證、權限檢查、流量控制。

django的View部分源碼

class View:
    """ Intentionally simple parent class for all views. Only implements dispatch-by-method and simple sanity checking. """
http_method_names = [<span class="hljs-string">'get'</span>, <span class="hljs-string">'post'</span>, <span class="hljs-string">'put'</span>, <span class="hljs-string">'patch'</span>, <span class="hljs-string">'delete'</span>, <span class="hljs-string">'head'</span>, <span class="hljs-string">'options'</span>, <span class="hljs-string">'trace'</span>]

<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__init__</span><span class="hljs-params">(self, **kwargs)</span>:</span>
    <span class="hljs-string">"""
    Constructor. Called in the URLconf; can contain helpful extra
    keyword arguments, and other things.
    """</span>
    <span class="hljs-comment"># Go through keyword arguments, and either save their values to our</span>
    <span class="hljs-comment"># instance, or raise an error.</span>
    <span class="hljs-keyword">for</span> key, value <span class="hljs-keyword">in</span> kwargs.items():
        setattr(self, key, value)</code></pre>

REST framework的APIView繼承了django的View，部分源碼如下
class APIView(View): 
# The following policies may be <span class="hljs-keyword">set</span> at either globally, <span class="hljs-keyword">or</span> per-view.
renderer_classes = api_settings.DEFAULT_RENDERER_CLASSES
parser_classes = api_settings.DEFAULT_PARSER_CLASSES
authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES
throttle_classes = api_settings.DEFAULT_THROTTLE_CLASSES
permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES
content_negotiation_class = api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS
metadata_class = api_settings.DEFAULT_METADATA_CLASS
versioning_class = api_settings.DEFAULT_VERSIONING_CLASS

# Allow dependency injection <span class="hljs-keyword">of</span> other settings <span class="hljs-keyword">to</span> make testing easier.
settings = api_settings

schema = DefaultSchema()</code></pre>
 
APIView多了一些屬性和方法，比如：身份認證、權限檢查、流量控制
 
            
 
             
authentication_classes 身份認證
 
             
permission_classes 權限檢查
 
             
throttle_classes 流量控制
 
            
 
django的View
 
先使用django自帶的view，獲取一個Card表里面的卡號信息：
 models.py設計card表
 
# models.py class Card(models.Model): '''銀行卡 基本信息 # 作者：上海悠悠，QQ交流群：750815713''' card_id = models.CharField(max_length=30, verbose_name="卡號", default="") card_user = models.CharField(max_length=10, verbose_name="姓名", default="") add_time = models.DateField(auto_now=True, verbose_name="添加時間") 
<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Meta</span>:</span>
    verbose_name_plural = <span class="hljs-string">'銀行卡賬戶'</span>
    verbose_name = <span class="hljs-string">"銀行卡賬戶_基本信息"</span>
    
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__str__</span><span class="hljs-params">(self)</span>:</span>
    <span class="hljs-keyword">return</span> self.card_id</code></pre>
 
views.py視圖的編寫
 
from django.http import JsonResponse from rest_framework import serializers from django.core import serializers as dj_serializers # 避免和rest_framework里面的serializers沖突 from .models import * from django.views.generic.base import View import json # 作者：上海悠悠，QQ交流群：750815713 
class CardListView(View):
 '''基於django的view實現獲取card列表'''
 def get(self, request):
 data = {}
 cards = Card.objects.all()
 data['result'] = json.loads(dj_serializers.serialize("json", cards))
 return JsonResponse(data)

urls.py設置訪問地址
from apiapp import views
from django.conf.urls import url
# 作者：上海悠悠，QQ交流群：750815713
urlpatterns = [
 url(r'^api/v1/cards/$', views.CardListView.as_view()),
]

訪問http://127.0.0.1:8000/api/v1/cards/,測試結果

REST framework的APIView
REST framework的APIView繼承了django的View類，先序列化Card類，這里的序列化用rest_framework里面的ModelSerializer
from rest_framework.response import Response
from rest_framework.views import APIView
from rest_framework import serializers
from .models import *
from rest_framework.permissions import IsAuthenticated,AllowAny
from rest_framework.authentication import TokenAuthentication
# 作者：上海悠悠，QQ交流群：750815713
class CardAPISerializer(serializers.ModelSerializer): # 繼承自ModelSerializer類
 '''序列化數據的類，根據model表來獲取字段'''
 class Meta:
 model = Card
 fields = 'all'
class CardListAPIView(APIView):
 '''REST framework的APIView實現獲取card列表 # 作者：上海悠悠，QQ交流群：750815713'''
 # authentication_classes = (TokenAuthentication,) # token認證
 # permission_classes = (IsAuthenticated,) # IsAuthenticated 僅通過認證的用戶
 permission_classes = (AllowAny,) # 允許所有用戶
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">get</span><span class="hljs-params">(self, request, format=None)</span>:</span>
    <span class="hljs-string">"""
    Return a list of all users.
    """</span>
    cards = Card.objects.all()
    serializer = CardAPISerializer(cards, many=<span class="hljs-keyword">True</span>)
    <span class="hljs-keyword">return</span> Response(serializer.data)</code></pre>

配置urls.py,設置訪問地址
from apiapp import views from django.conf.urls import url # 作者：上海悠悠，QQ交流群：750815713 
urlpatterns = [
 url(r'^api/v1/cardlist/$', views.CardListAPIView.as_view()),
 
]

訪問http://127.0.0.1:8000/api/v1/cardlist/,測試結果