如何不重複自己（DRY）

Question

我有我的代碼兩個地方基本授權。我想將它作爲一個函數分開，而不是重複代碼。

我的應用程序：

from django.shortcuts import render 
from django.views.generic import View 
from django.http import HttpResponse, Http404 
from django.contrib.auth import authenticate 
from django.core.exceptions import PermissionDenied 
import base64 

from notes.models import Note, load_initial_data 


class NoteListView(View): 



    def filter_queryset(self, query_set): 
     query_params = self.request.GET 
     if 'board' in query_params: 
      query_set = query_set.filter(board=query_params['board']) 
     return query_set 

    def get(self, request): 
     load_initial_data() 
     query_set = self.filter_queryset(Note.objects.all()) 
     basic_auth = True 
     # this lines below ! 
     if basic_auth: 
      if 'HTTP_AUTHORIZATION' in request.META: 
       auth = request.META['HTTP_AUTHORIZATION'].split() 
       if len(auth) == 2: 
        if auth[0].lower() == "basic": 
         uname, passwd = base64.b64decode(auth[1]).split(':') 
         user = authenticate(username=uname, password=passwd) 
         if user is not None and user.is_active: 
          request.user = user 
          if not request.user.is_staff: 
           raise PermissionDenied 
          return HttpResponse(query_set) 

      response = HttpResponse() 
      response.status_code = 401 
      response['WWW-Authenticate'] = 'Basic realm="%s"' % "Basic Auth Protected" 
      return response 
     else: 
      return HttpResponse(query_set) 



class NoteView(View): 

    def get_object(self, obj_id): 
     try: 
      return Note.objects.get(id=int(obj_id)) 
     except IndexError: 
      raise Http404 

    def get(self, request, note_id): 
     load_initial_data() 
     basic_auth = True 
     #this lines below 
     if basic_auth: 
      if 'HTTP_AUTHORIZATION' in request.META: 
       auth = request.META['HTTP_AUTHORIZATION'].split() 
       if len(auth) == 2: 
        if auth[0].lower() == "basic": 
         uname, passwd = base64.b64decode(auth[1]).split(':') 
         user = authenticate(username=uname, password=passwd) 
         if user is not None and user.is_active: 
          request.user = user 

          return HttpResponse(self.get_object(note_id)) 

      response = HttpResponse() 
      response.status_code = 401 
      response['WWW-Authenticate'] = 'Basic realm="%s"' % "Basic Auth Protected" 
      return response 
     else: 
      return HttpResponse(self.get_object(note_id)) 

我重複代碼類NoteListView在GET FUNC和類NoteView。我不知道如何分開這個功能。我標註了重複的評論。有什麼建議麼？

Answer 1

我將跳過對不重複自己，但Utkbansal的評論跟進，你可以創建自己的混合類，或創建從兩種觀點派生自己的基本視圖強制性的笑話。即對象繼承。這就是說，最簡單的（我敢說，奇的！）的方式來做到這一點是通過繼承PermissionRequiredMixin：

from django.contrib.auth.mixins import PermissionRequiredMixin 

class BasicAuthRequired(PermissionRequiredMixin): 
    def __init__(self): 
     super(BasicAuthRequired, self).__init__() 
     self.basic_auth = True 

    def has_permission(self): 
     if self.basic_auth: 
      if 'HTTP_AUTHORIZATION' not in request.META: 
       return False 
      auth = request.META['HTTP_AUTHORIZATION'].split() 
      if len(auth) != 2 or auth[0].lower() != "basic": 
       return False 
      uname, passwd = base64.b64decode(auth[1]).split(':') 
      user = authenticate(username=uname, password=passwd) 
      if not user or not user.is_active: 
       return False 
      self.request.user = user # from `View` 
      return user.is_staff 
     return True # some other type of auth 

在你的意見

現在，你可以做，我們可以放心，基本身份驗證以下已覈實並妥善處理，只是處理的正面案例：

class NoteView(BasicAuthRequired, View): 
    def get_object(self, obj_id): 
     try: 
      return Note.objects.get(id=int(obj_id)) 
     except IndexError: 
      raise Http404 

    def get(self, request, note_id): 
     load_initial_data() 
     return HttpResponse(self.get_object(note_id))