django-tutorial/mysite/polls/views.py

from django.shortcuts import render, get_object_or_404
from django.http import HttpResponse, Http404, HttpResponseRedirect
from django.template import loader
from django.urls import reverse
from django.views import generic
from .models import Question, Choice

# Create your views here.
class IndexView(generic.ListView):
    template_name = 'polls/index.html'
    context_object_name = 'question_list'

    def get_queryset(self):
        # Return last 5 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/resulthtml'

def index(request):
    question_list = Question.objects.order_by('-pub_date')[:5]
    context = { 'question_list': question_list }
    return render(request, 'polls/index.html', context)

def detail(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/detail.html', {'question': question})

def result(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/result.html', {'question': question})

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):
        return render(request, 'polls/detail.html', {"question": question, "error_message": "You didn't select a choice",})
    else:
        selected_choice.votes += 1
        selected_choice.save()
        return HttpResponseRedirect(reverse('polls:result', args=(question.id, )))