Django L4 编写你的第一个Django应用
编写一个简单的表单
$ cat tasks/views.py | tail -18 def vote(request, question_id): p = get_object_or_404(Questions, pk=question_id) try: selected_choice = p.choice_set.get(pk=request.POST['choice']) except (KeyError, Choice.DoesNotExist): # Redisplay the question voting form. return render(request, 'tasks/detail.html', { 'question': p, '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('tasks:results', args=(p.id,)))
$cat tasks/urls.py #!/usr/bin/env python #-*- coding: utf-8 -*- __author__ = 'Ye Lin' __date__ = '17-2-9' from django.conf.urls import url from . import views urlpatterns = [ url(r'^$' , views.index , name='index'), url(r'^(?P<question_id>[0-9]+)/$', views.detail, name='detail'), # http://127.0.0.1:20001/tasks/1/results/ url(r'^(?P<question_id>[0-9]+)/results/$', views.results, name='results'), # http://127.0.0.1:20001/tasks/1/vote/ url(r'^(?P<question_id>[0-9]+)/vote/$', views.vote, name='vote'), ]
由于这种情况非常普遍,Django提供了一种叫做“generic views”的系统可以方便地进行处理。
使用通用视图,代码少点
改良URLconf
#!/usr/bin/env python #-*- coding: utf-8 -*- __author__ = 'Ye Lin' __date__ = '17-2-9' from django.conf.urls import url from . import views urlpatterns = [ url(r'^$', views.IndexView.as_view(), name='index' ), url(r'^(?P<pk>[0-9]+)/$', views.DetailView.as_view(), name='detail'), url(r'^(?P<pk>[0-9]+)/results/$', views.ResultsView.as_view(), name='results'), url(r'^(?P<question_id>[0-9]+)/vote/$', views.vote, name='vote'), ]
改良视图
from django.shortcuts import render , get_object_or_404 , HttpResponseRedirect from django.http import Http404 from django.http import HttpResponse from django.core.urlresolvers import reverse from django.views import generic # Create your views here. from .models import * from django.template import RequestContext, loader class IndexView(generic.ListView): template_name = 'tasks/index.html' context_object_name = 'latest_question_list' def get_queryset(self): """Return the last five published questions.""" return Questions.objects.order_by('-pub_date')[:5] class DetailView(generic.DetailView): model = Questions template_name = 'tasks/detail.html' class ResultsView(generic.DetailView): model = Questions template_name = 'tasks/results.html' def vote(request, question_id): p = get_object_or_404(Questions, pk=question_id) try: selected_choice = p.choice_set.get(pk=request.POST['choice']) except (KeyError, Choice.DoesNotExist): # Redisplay the question voting form. return render(request, 'tasks/detail.html', { 'question': p, '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('tasks:results', args=(p.id,)))