【原】python測(cè)試開(kāi)發(fā)django-62.基于類的視圖(APIView和View)

上海悠悠 2021-05-27

展開(kāi)全文

前言

django中編輯視圖views.py有兩種方式，一種是基于類的實(shí)現(xiàn)，另外一種是函數(shù)式的實(shí)現(xiàn)方式，兩種方法都可以用。
REST框架提供了一個(gè)APIView類，它是Django View類的子類。

View與APIView的區(qū)別

View是Django默認(rèn)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的不同之處在于：

傳入到視圖方法中的是REST framework的Request對(duì)象，而不是Django的HttpRequeset對(duì)象；
視圖方法可以返回REST framework的Response對(duì)象，視圖會(huì)為響應(yīng)數(shù)據(jù)設(shè)置（render）符合前端要求的格式；
任何APIException異常都會(huì)被捕獲到，并且處理成合適的響應(yīng)信息；
APIException異常捕獲
在進(jìn)行dispatch()分發(fā)前，會(huì)對(duì)請(qǐng)求進(jìn)行身份認(rèn)證、權(quán)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 = ['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace']

    def __init__(self, **kwargs):
        """
        Constructor. Called in the URLconf; can contain helpful extra
        keyword arguments, and other things.
        """
        # Go through keyword arguments, and either save their values to our
        # instance, or raise an error.
        for key, value in kwargs.items():
            setattr(self, key, value)

REST framework的APIView繼承了django的View，部分源碼如下

class APIView(View):

    # The following policies may be set at either globally, or 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 of other settings to make testing easier.
    settings = api_settings

    schema = DefaultSchema()

APIView多了一些屬性和方法，比如：身份認(rèn)證、權(quán)限檢查、流量控制

authentication_classes 身份認(rèn)證
permission_classes 權(quán)限檢查
throttle_classes 流量控制

django的View

先使用django自帶的view，獲取一個(gè)Card表里面的卡號(hào)信息：
models.py設(shè)計(jì)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(hào)", 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(shí)間")

    class Meta:
        verbose_name_plural = '銀行卡賬戶'
        verbose_name = "銀行卡賬戶_基本信息"

    def __str__(self):
        return self.card_id

views.py視圖的編寫(xiě)

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):
    '''基于django的view實(shí)現(xiàn)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(shè)置訪問(wèn)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(wèn)http://127.0.0.1:8000/api/v1/cards/,測(cè)試結(jié)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(shù)據(jù)的類，根據(jù)model表來(lái)獲取字段'''
    class Meta:
        model = Card
        fields = '__all__'

class CardListAPIView(APIView):
    '''REST framework的APIView實(shí)現(xiàn)獲取card列表 # 作者：上海悠悠，QQ交流群：750815713'''
    # authentication_classes = (TokenAuthentication,)  # token認(rèn)證
    # permission_classes = (IsAuthenticated,)   # IsAuthenticated 僅通過(guò)認(rèn)證的用戶
    permission_classes = (AllowAny,)  # 允許所有用戶

    def get(self, request, format=None):
        """
        Return a list of all users.
        """
        cards = Card.objects.all()
        serializer = CardAPISerializer(cards, many=True)
        return Response(serializer.data)

配置urls.py,設(shè)置訪問(wèn)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(wèn)http://127.0.0.1:8000/api/v1/cardlist/,測(cè)試結(jié)果