python - 如果没有在 django 项目的 html 标签中分配 'action' 值，它仍然会渲染页面并将值提交到数据库，如何？

Question

urls.py

from django.contrib import admin
from django.urls import path
from poll import views

urlpatterns = [
    path('', views.poll_home, name="poll_home"),
    path('poll_details/<int:id>/', views.poll_details, name="poll_details"),
    path('<int:id>/', views.poll, name='poll')
]

views.py

def poll(request, id=None):
    if request.method == 'GET':
        try:
            question=Question.objects.get(id=id)
        except:
            raise Http404
        return render(request, 'poll/poll.html',{'question':question})
    if request.method == 'POST':
        user_id=1
        data=request.POST['choice']
        ret = Answer.objects.create(user_id=user_id,choice_id = data)
        if ret :
            return HttpResponse('Your vote is done successfully.')
        else:
            return HttpResponse('Your vote is not done successfully.')
        return render()

poll.html

{% extends 'employee/employee_home.html'%}

{% block content%}
<h1>Vote Page</h1>
<h3>{{ question.title}}</h3>
<form method="POST" action="">
    {% csrf_token %}
    {% if question%}
        {% for choice in question.choices %}
            <input type="radio" name="choice" value="{{ choice.id }}">
            <label>{{ choice.text }}</label>
        {% empty %}
            <p>There is no choice available  for this question</p>
        {% endfor%}
        <button type="submit">Vote</button>
    {% else %}
         <p>There is no choice available  for this question</p>
    {% endif%}
</form>
<h4><i>This question is created by {{question.created_by.first_name}}</i></h4>
{% endblock content%}

即使我没有在 html 页面中提及 action 值，它仍然会提交数据并成功显示结果

我想了解 django 如何知道操作路径

Answer 1

这部分造成困惑:

if request.method == 'POST':
    user_id = 1
    data = request.POST['choice']
    ret = Answer.objects.create(user_id=user_id, choice_id=data)
    if ret:
        return HttpResponse('Your vote is done successfully.')
    else:
        return HttpResponse('Your vote is not done successfully.')
    return render()

该行导致在每个 POST 请求上创建对象:Answer.objects.create(user_id=user_id, choice_id=data)，并且新的对象实例将分配给 ret 变量始终为 True，这就是您收到成功消息的原因。更好的工作流程是:

if request.method == 'POST':
    try:
        # do not hardcode user id,
        # use user instance from the request
        user = request.user
        choice = request.POST['choice']
        ret = Answer.objects.create(user=user.id, choice_id=choice)
        return HttpResponse('Your vote is done successfully.')    
    except Exception:
        return HttpResponse('Your vote is not done successfully.')
    return render()