[python] Django Generic View 사용하기

제너릭 뷰란 함수형 view가 아닌 class형 view이다.

class형 view를 통해 중복되는 내용을 제거할 수 있어서 코드 길이가 짧아진다.

url config 수정

polls/urls.py

from django.urls import path
from . import views

app_name = 'polls'
urlpatterns = [
    path('', views.IndexView.as_view(), name='index'),
    path('<int:pk>/', views.DetailView.as_view(), name='detail'),
    path('<int:pk>/results/', views.ResultsView.as_view(), name='results'),
    path('<int:question_id>/vote/', views.vote, name='vote'),
]

두 번째와 세 번째 패턴의 경로 문자열에서 일치하는 패턴들의 이름이 <question_id>  에서 <pk> 로 변경되었습니다.

pk란 DB내의 하나의 열, 즉 하나의 데이터를 구분할 수 있는 값이다

또한 django가 원래 갖고있는 함수인 **as_view()**를 사용해 view를 호출할 수 있다.

views 수정

polls/views.py

from django.http import HttpResponseRedirect
from django.shortcuts import get_object_or_404, render
from django.urls import reverse
from django.views import generic

from .models import Choice, Question

class IndexView(generic.ListView):
    template_name = 'polls/index.html'
    context_object_name = 'latest_question_list'

    def get_queryset(self):
        """Return the last five published questions."""
        return Question.objects.order_by('-pub_date')[:5]

class DetailView(generic.DetailView):
    model = Question
    template_name = 'polls/detail.html'

class ResultsView(generic.DetailView):
    model = Question
    template_name = 'polls/results.html'

def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except (KeyError, Choice.DoesNotExist):
        # Redisplay the question voting form.
        return render(request, 'polls/detail.html', {
            'question': question,
            'error_message': "You didn't select a choice.",
        })
    else:
        selected_choice.votes += 1
        selected_choice.save()
        # Always return an HttpResponseRedirect after successfully dealing
        # with POST data. This prevents data from being posted twice if a
        # user hits the Back button.
    return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))