django系列8:最佳化vote頁面，使用通用視圖降低代碼冗餘

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修改detail.html，將它變為一個可用的投票頁面

<h1>{{ question.question_text }}</h1>{% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %}<form action="{% url ‘polls:vote‘ question.id %}" method="post">{% csrf_token %}{% for choice in question.choice_set.all %}    <input type="radio" name="choice" id="choice{{ forloop.counter }}" value="{{ choice.id }}">    <label for="choice{{ forloop.counter }}">{{ choice.choice_text }}</label><br>{% endfor %}<input type="submit" value="Vote"></form>

　　

修改views.py中vote的部分，和detail.html聯合起來，記錄票數，編輯對應的操作反饋

from django.http import HttpResponse, HttpResponseRedirectfrom django.shortcuts import get_object_or_404, renderfrom django.urls import reversefrom .models import Choice, 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):        # 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,)))

　　

裡面用到了重新導向，HttpResponseRedirect，重新導向頁面到 polls:results，傳入的content是question.id，這裡對投票完成頁面的results的views做最佳化

 

from django.shortcuts import get_object_or_404, renderdef results(request, question_id):    question = get_object_or_404(Question, pk=question_id)    return render(request, ‘polls/results.html‘, {‘question‘: question})　　

建立一個results.html，顯示投票結果

<h1>{{ question.question_text }}</h1><ul>{% for choice in question.choice_set.all %}    <li>{{ choice.choice_text }} -- {{ choice.votes }} vote{{ choice.votes|pluralize }}</li>{% endfor %}</ul><a href="{% url ‘polls:detail‘ question.id %}">Vote again?</a>

 

details和results的view 有很多代碼相同之處，這裡修改為使用通用視圖，降低代碼冗餘

修改conf

from django.urls import pathfrom . import viewsapp_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‘),]

　　修改views

from django.http import HttpResponseRedirectfrom django.shortcuts import get_object_or_404, renderfrom django.urls import reversefrom django.views import genericfrom .models import Choice, Questionclass 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):    ... # same as above, no changes needed.

　　

 

至此，教程結束。

剩餘的測試代碼部分，最佳化介面部分，打包和引用部分，已經執行過，但是篇幅太長，建議直接登入官網查閱文檔。

https://docs.djangoproject.com/en/2.1/intro/tutorial06/

 

django系列8:最佳化vote頁面，使用通用視圖降低代碼冗餘