上一篇已经完成了polls的基本功能,接下来完善剩下的vote功能和并使用generic views改进请求处理view。包含表单的简单运用和前后台参数传递。
目录
- vote:完善投票功能
- generic views:改进views.py
vote
编辑detail.html,添加投票投票功能
<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>
- 添加了form表单,使用post提交,提交到的地址是polls:vote代表一个地址,比如:http://127.0.0.1:8000/polls/4/vote/.
- 这里涉及到了表单提交,添加{% csrf_token %}防止csrf攻击,原理就是每次使用的token不一致,导致无法进行伪造请求,从而防止。
- forloop.counter是for循环的计数器。
编辑views.py添加投票功能,注意引入相关的类
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 did`t select choice.",
})
else:
selected_choice.votes += 1
selected_choice.save()
return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))
request.POST['choice']从post请求里面获取前台传递过来的参数,request.POST 是一个dictionary,键是参数名,值是参数值,档案如果是get请求的话就是request.GET
return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))在投票成功之后将页面进行了重定向,防止用户使用浏览器的回退功能之后重复提交表单
到现在为止功能已经完成了,可以进行测试了,启动服务器然后测试相关功能
generic views
对于很多web app来说,需要展示内容的方式相近,比如:查看某个列表,查看某一个的具体内容等等,为此Django提供了generic views——Django诠释了什么是快速便捷开发!
使用generic views改写views.py
from django.shortcuts import render, get_object_or_404
from django.http import HttpResponse, Http404, HttpResponseRedirect
from models import Question, Choice
from django.views import generic
from django.core.urlresolvers import reverse
# Create your views here.
class IndexView(generic.ListView):
template_name = 'polls/index.html'
context_object_name = 'latest_question_list'
def get_queryset(self):
return Question.objects.order_by('-publ_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):
return render(request, 'polls/detail.html', {
'question': question,
'error_message':"you did`t select choice.",
})
else:
selected_choice.votes += 1
selected_choice.save()
return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))
我们将index,detail,result都改写了,使用到了ListView和DetailView。
IndexView复写了get_quesryset方法来实现我们自己的逻辑,设置了模板页面和返回的参数名称
DetailView设置了展示详细