w3cschool_jdango_demo/polls/views.py

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


# Create your views here.

# def index(request):
#     latest_question_list = Question.objects.order_by('-pub_date')[:5]
#     # output = ', '.join([q.question_text for q in latest_question_list])
#     # return HttpResponse(output)
#     # 模板使用方式1
#     # template = loader.get_template('index.html')
#     # context = {
#     #     'latest_question_list': latest_question_list,
#     # }
#     # return HttpResponse(template.render(context, request))
#     # 模板使用方法2
#     context = {
#         'latest_question_list': latest_question_list,
#     }
#     return render(request, 'index.html', context)
#
#
# def detail(request, question_id):
#     # return HttpResponse(f"You're looking at question {question_id}.")
#     # 添加404页面展示 方式1
#     # try:
#     #     question = Question.objects.get(pk=question_id)
#     #     context = {'question': question}
#     #     print(context)
#     # except Question.DoesNotExist:
#     #     raise Http404("Question does not exist")
#     # return render(request, 'detail.html', context)
#
#     # 添加404页面展示 方式2
#     question = get_object_or_404(Question, pk=question_id)
#     return render(request, 'detail.html', {'question': question})
#
#
# def result(request, question_id):
#     question = get_object_or_404(Question, pk=question_id)
#     return render(request, 'results.html', {'question': question})
#     # return HttpResponse(f"You're looking at the result of question {question_id}.")

# 通用视图

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

    def get_queryset(self):
        return Question.objects.order_by('-pub_date')[:5]


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


class ResultView(generic.DetailView):
    model = Question
    template_name = '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):
        return render(request, '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,)))
    # return HttpResponse(f"You're voting on question {question_id}")