创建第一个Django app-part4

写一个最小的表单

编辑 detail.html

点击查看代码

<form action="{% url 'polls:vote' question.id%}" method="post">
    {% csrf_token %}
    <fieldset>
        <legend><h1>{{ question.question_text }}</h1></legend>
        {% if error_message %}
            <p><strong>{{ error_message }}</strong></p>
        {% endif %}

        {% 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 %}
    </fieldset>
    {% if not error_message %}
        <input type="submit" value="Vote">
    {% endif %}
</form> 

注意这里使用了命名空间polls:,所以需要先添加，修改polls/urls.py, 添加如下代码，同时之前的地址前面都需要加上polls:

app_name = "polls"

修改polls/views.py中的vote，detail，results方法

点击查看代码

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

def detail(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    choice_counts = question.choice_set.count()
    if choice_counts<=0:
        return render(request, 'polls/detail.html', {"question": question, "error_message": "You didn't select a choice."})
    else:
        return render(request, 'polls/detail.html', {"question": question})

def results(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, "polls/results.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:results", args=(question_id, )))

创建模板results.html

点击查看代码

<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>

修改view和url.py

修改polls/urls.py

点击查看代码

from os import name
from django.urls import path
from . import views

app_name = "polls"
urlpatterns = [
    # path("", views.index, name="index"),
    # path("<int:question_id>/", views.detail, name="detail"),
    # path("<int:question_id>/results/", views.results, name="results"),
    # path("<int:question_id>/vote/", views.vote, name="vote"),
    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polls/views.py

点击查看代码

from django.views import generic

class IndexView(generic.ListView):
    template_name = "polls/index.html"
    context_object_name = "latest_question_list"
    
    def get_queryset(self) -> QuerySet[Any]:
        return Question.objects.order_by("-pub_date")[:5]

'''
    这种写法，我尝试过加上其它的上下文，例如detail.html中存在的error_message,
    但是报错了，应该是model这个属性和其它上下文不能同时存在。

    所以还是用方法比较好，更加的简单，容易理解也更灵活
'''
class DetailView(generic.DetailView):
    model = Question
    template_name = "polls/detail.html"

class ResultsView(generic.DetailView):
    model = Question
    template_name = "polls/results.html"