APIView和View的区别

前言

django中编辑视图views.py有两种方式，一种是基于类的实现，另外一种是函数式的实现方式，两种方法都可以用。
REST框架提供了一个APIView类，它是Django View类的子类。

View与APIView的区别

View是Django默认的视图基类，APIView是REST framework提供的所有视图的基类, 继承自Django的View。

APIView与View的不同之处在于：

• 传入到视图方法中的是REST framework的Request对象，而不是Django的HttpRequeset对象；
• 视图方法可以返回REST framework的Response对象，视图会为响应数据设置（render）符合前端要求的格式；
• 任何APIException异常都会被捕获到，并且处理成合适的响应信息；APIException异常捕获
• 在进行dispatch()分发前，会对请求进行身份认证、权限检查、流量控制。

django的View部分源码

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继承了django的View，部分源码如下
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多了一些属性和方法，比如：身份认证、权限检查、流量控制

authentication_classes 身份认证
permission_classes 权限检查
throttle_classes 流量控制

django的View
先使用django自带的view，获取一个Card表里面的卡号信息：

models.py设计card表
# models.py
class Card(models.Model):
    '''银行卡 基本信息 # 作者：上海悠悠，QQ交流群：750815713'''
    card_id = models.CharField(max_length=30, verbose_name="卡号", default="")
    card_user = models.CharField(max_length=10, verbose_name="姓名", default="")
    add_time = models.DateField(auto_now=True, verbose_name="添加时间")
<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Meta</span>:</span>
    verbose_name_plural = <span class="hljs-string">'银行卡账户'</span>
    verbose_name = <span class="hljs-string">"银行卡账户_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视图的编写
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冲突
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):

'''基于django的view实现获取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设置访问地址
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()),
]

访问http://127.0.0.1:8000/api/v1/cards/,测试结果

REST framework的APIView
REST framework的APIView继承了django的View类，先序列化Card类，这里的序列化用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):   # 继承自ModelSerializer类

'''序列化数据的类，根据model表来获取字段'''

class Meta:

model = Card

fields = 'all'
class CardListAPIView(APIView):

'''REST framework的APIView实现获取card列表 # 作者：上海悠悠，QQ交流群：750815713'''

# authentication_classes = (TokenAuthentication,)  # token认证

# permission_classes = (IsAuthenticated,)   # IsAuthenticated 仅通过认证的用户

permission_classes = (AllowAny,)  # 允许所有用户
<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,设置访问地址
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()),
]

访问http://127.0.0.1:8000/api/v1/cardlist/,测试结果