DJANGO

Question

我正在尝试使表单从用户那里获取信息并使用此信息发送电子邮件。这是我的代码：

#forms.py
from django import forms

class ContactForm(forms.Form):
    nome = forms.CharField(required=True)
    email = forms.EmailField(required=True)
    msg = forms.CharField(
        required=True,
        widget=forms.Textarea
    )

#views.py
from django.shortcuts import render, redirect, get_object_or_404, HttpResponseRedirect, render_to_response
from django.core.mail import send_mail
from .forms import ContactForm

def contato(request):
    form_class = ContactForm
    if request.method == 'POST':
        form = form_class(request.POST)
        if form.is_valid():
            nome = request.POST.get('nome')
            email = request.POST.get('email')
            msg = request.POST.get('msg')

            send_mail('Subject here', msg, email, ['testmail@gmail.com'], fail_silently=False)
            return HttpResponseRedirect('blog/inicio')
    return render(request, 'blog/inicio.html', {'form': form})


#contato.html
{% extends "blog/base.html" %}
{% block content %}

                    <form role="form" action="" method="post">
                        {% csrf_token %}
                        {{ form.as_p }}
                        <button type="submit">Submit</button>
                    </form>
{% endblock %}

当我尝试进入联系页面时出现此错误：

local variable 'form' referenced before assignment

它说错误在views.py这一行：

return render(request, 'blog/inicio.html', {'form': form})

我对 Django 有点陌生，你能帮帮我吗？

Answer 1

您在此 if request.method == 'POST': 块中定义 form 变量。如果您使用 GET 请求访问 view，则 form 未定义。您应该将视图更改为如下所示：

def contato(request):
    form_class = ContactForm
    # if request is not post, initialize an empty form
    form = form_class(request.POST or None)
    if request.method == 'POST':

        if form.is_valid():
            nome = request.POST.get('nome')
            email = request.POST.get('email')
            msg = request.POST.get('msg')

            send_mail('Subject here', msg, email, ['testmail@gmail.com'], fail_silently=False)
            return HttpResponseRedirect('blog/inicio')
    return render(request, 'blog/inicio.html', {'form': form})

Answer 2

如果可以这样说 - 附带损害 通过初始化一个空的 form ，那么你也可以提供一个 dummy 值作为填充符，直到 request.POST 被初始化 ...

def contato(request):
    form = "Dummy String"
    form_class = ContactForm

    # if request is not post, initialize an empty form
    #form = form_class(request.POST or None) # Maybe Not 

    form = form_class(request.POST) # Instead 
    if request.method == 'POST':
        if form.is_valid():
            nome = request.POST.get('nome')
            email = request.POST.get('email')
            msg = request.POST.get('msg')

            send_mail('Subject here', msg, email, ['testmail@gmail.com'], fail_silently=False)
            return HttpResponseRedirect('blog/inicio')
    return render(request, 'blog/inicio.html', {'form': form})

Answer 3

Django 文档处理这个问题，但与其他答案略有不同。参见 https://docs.djangoproject.com/en/dev/topics/forms/#using-a-form-in-a-view

使用 else，如果请求不是 POST，则创建空白表单。下面是直接从文档粘贴的。

def get_name(request):
    # if this is a POST request we need to process the form data
    if request.method == 'POST':
        # create a form instance and populate it with data from the request:
        form = NameForm(request.POST)
        # check whether it's valid:
        if form.is_valid():
            # process the data in form.cleaned_data as required
            # ...
            # redirect to a new URL:
            return HttpResponseRedirect('/thanks/')

    # if a GET (or any other method) we'll create a blank form
    else:
        form = NameForm()

    return render(request, 'name.html', {'form': form})

Answer 4

您遇到的唯一问题是您没有将 ContactForm 声明为函数，从这个改变;

def contato(request):
    form_class = ContactForm
    if request.method == 'POST':

至；

def contato(request):
    form_class = ContactForm()
    if request.method == 'POST':

DJANGO - 赋值前引用的局部变量 'form'

DJANGO - local variable 'form' referenced before assignment

python

forms

django-forms