python - 自定义 Django 登录页面不呈现登录表单

Question

Django 新手在这里尝试创建自定义登录表单、 View 和模板。我的问题是我认为的逻辑导致表单不显示，相反，else 语句的错误消息总是出现。我确定我错过了什么，我只是不知道它是什么。谁能指出我正确的方向？我一直在使用 Django 文档和本教程:http://www.djangobook.com/en/2.0/chapter14.html谢谢!

更新:用户@AKS 指出我没有正确处理 POST/GET 逻辑，所以我接受了这个作为答案。一旦我调整了我的代码，表单仍然无法显示，所以我在 HTML 文件中发现了一些错误并修复了它们。更正后的代码显示在本文底部。

-- views.py --

# Django imports
from django import forms
from django.contrib import auth
from django.contrib.auth.decorators import login_required
from django.contrib.auth.forms import UserCreationForm
from django.contrib.auth.models import User
from django.contrib.auth.views import login, logout
from django.http import HttpResponse, HttpResponseRedirect
from django.shortcuts import get_object_or_404, redirect, render
from django.utils import timezone

# Local Django imports
from .models import *
from .forms import *


def login(request, method='POST'):
    '''Shows a login form and a registration link.'''

    username = request.POST.get('username', '')
    password = request.POST.get('password', '')
    user = auth.authenticate(username=username, password=password)

    if user is not None and user.is_active:
        auth.login(request, user)
        return HttpResponseRedirect("client/items")

    else:
        return HttpResponse("Invalid login. Please try again.")

    return render(request, "registration/login.html", {'next':'/client/items'})

-- 注册/登录.html --

{% extends "registration/base.html" %}

{% block content %}

{% if form.errors %}
<p>Your username and password didn't match. Please try again.</p>
{% endif %}

<form method="post" action='/login'>{% csrf_token %}
<table>
<tr>
    <td>{{ form.username.label_tag }}</td>
    <td>{{ form.username }}</td>
</tr>
<tr>
    <td>{{ form.password.label_tag }}</td>
    <td>{{ form.password }}</td>
</tr>
</table>

<input type="submit" value="Login" />
<input type="hidden" name="next" value="{{ next }}" />
</form>

{% endblock %}

-- 设置.py --

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'clients'
]

MIDDLEWARE_CLASSES = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

-- app/urls.py --

from django.conf.urls import url
from . import views

urlpatterns = [
    url(r'^$', views.login, name='login'),
    url(r'^register$', views.register, name='register'),
    url(r'^client/items$', views.client_items, name='client_items'),
    url(r'^client/new_item$', views.new_item, name='new_item'),
    url(r'^client/edit_item$', views.edit_item, name='edit_item'),
    url(r'^client/item_detail$', views.item_detail, name='item_detail'),
]

-- 更正注册/login.html --

{% extends "registration/base.html" %}

{% block content %}

{% if form.errors %}
<p>Your username and password didn't match. Please try again.</p>
{% endif %}

<form method="post" action=''>{% csrf_token %}
    <label for="username">Username:</label>
    <input type="text" name="username" value="" id="username"><br>
    <label for="password">Password:</label>
    <input type="password" name="password" value="" id="password"><br>

    <input type="submit" value="Login" />
    <input type="hidden" name="next" value="{{ next }}" />
</form>

{% endblock %}

Answer 1

似乎执行永远不会到达最后一个 return 语句，因为它要么满足 if 条件，要么返回 Invalid Login 响应。

if user is not None and user.is_active:
    auth.login(request, user)
    return HttpResponseRedirect("client/items")

else:
    return HttpResponse("Invalid login. Please try again.")

return render(request, "registration/login.html", {'next':'/client/items'})

看来您需要处理 POST 请求中的表单，并在 GET 请求的情况下返回登录表单:

def login(request, method='POST'):
    '''Shows a login form and a registration link.'''

    if request.method == 'POST':
        username = request.POST.get('username', '')
        password = request.POST.get('password', '')
        user = auth.authenticate(username=username, password=password)

        if user is not None and user.is_active:
            auth.login(request, user)
            return HttpResponseRedirect("client/items")

        else:
            return HttpResponse("Invalid login. Please try again.")

    # if not POST then return login form    
    return render(request, "registration/login.html", {'next':'/client/items'})