Django登录后访问dashboard报405 Method Not Allowed错误求助

问题现象 #

登录页提交登录请求后，直接向/dashboard/发送POST请求，触发HTTP 405 Method Not Allowed错误，但访问其他页面（如dbtable）完全正常。终端报错信息如下：

[02/Oct/2022 17:04:24] "GET / HTTP/1.1" 200 4720
Method Not Allowed (POST): /dashboard/
Method Not Allowed: /dashboard/
[02/Oct/2022 17:04:42] "POST /dashboard/ HTTP/1.1" 405 0

代码问题分析 #

1. 登录表单提交目标错误 #

登录表单的action直接指向dashboard路由，且使用POST方法提交，但DashboardPageView继承自TemplateView，默认仅支持GET请求，不处理POST请求，因此返回405错误。

2. 登录视图逻辑存在致命错误 #

register_login视图中，第一个return render语句写在登录判断代码之前，导致登录相关逻辑永远无法执行；同时条件判断的写法存在逻辑错误，无法正确区分注册和登录请求。

相关代码片段 #

urls.py

urlpatterns = [
    path('',views.register_login, name='login'),
    path('dashboard/', DashboardPageView.as_view(), name='dashboard'),
    path('dbtable/', views.DBTableView, name = 'dbtable'),
]

views.py（原错误代码）

def register_login(request):
    form = UserCreationForm()
    if "register" in request.method == 'POST':
        form = UserCreationForm(request.POST) == "Register"
        if form.is_valid():
            form.save()
            user = form.cleaned_data['username']
            messages.success(request,"Account was Created for " + user)
        
    context = {'form':form}
    return render(request,'login.html',context)  # 提前返回，后续登录代码无法执行
    
    if "login" in request.method == "POST":
        if request.POST['submit'] == 'Login':
            username = request.POST['username']
            password = request.POST['password']

            user = authenticate(request, username=username, password=password)

            if user is not None:
                login(request,user)
                return redirect('login')  # 登录成功未跳转到dashboard
            else:
                messages.error(request, 'Wrong Username or password')
    context = {}
    return render(request,'login.html',context)
            
class DashboardPageView(TemplateView): 
    template_name = 'dashboard.html'
    def get_context_data(self, **kwargs):
        context = super(DashboardPageView, self).get_context_data(**kwargs)
        context['plot'] = plot1.cumulative_plot()
        return context

login.html（原错误代码）

<!-- SIGN IN -->
<div class="col align-items-center flex-col sign-in">
    <div class="form-wrapper align-items-center">
        <div class="form sign-in">
            <div class="input-group">
                <form  action = "{% url 'dashboard' %}" method="POST" name="login" value="login">
                    {% csrf_token %}
                    <i class='bx bxs-user'></i>
                    <input type="text" name = "username"  placeholder="Username" class="form-control" Required>
            
                <i class='bx bxs-lock-alt'></i>
                <input type="password" name = "password" placeholder="Password" class="form-control" Required>
                    <button type="submit" >
                        Sign in
                    </button>
                    <p>
                        <b>
                            Forgot password?
                        </b>
                    </p>
                    <p>
                        <span>
                            Don't have an account?
                        </span>
                        <b onclick="toggle()" class="pointer">
                            Sign up here
                        </b>
                    </p>
                </form>
            </div>

解决方案 #

步骤1：修正登录表单提交目标 #

将登录表单的action指向登录视图（当前页面或{% url 'login' %}），同时给提交按钮添加name和value属性，方便视图区分请求类型：

修改后的login.html表单部分：

<form action="{% url 'login' %}" method="POST">
    {% csrf_token %}
    <i class='bx bxs-user'></i>
    <input type="text" name="username" placeholder="Username" class="form-control" required>

    <i class='bx bxs-lock-alt'></i>
    <input type="password" name="password" placeholder="Password" class="form-control" required>
    
    <!-- 添加name和value，用于视图判断登录请求 -->
    <button type="submit" name="submit" value="Login">
        Sign in
    </button>
    <!-- 注册按钮也需添加对应属性，示例：<button type="submit" name="submit" value="Register">Sign up</button> -->
    
    <p>
        <b>Forgot password?</b>
    </p>
    <p>
        <span>Don't have an account?</span>
        <b onclick="toggle()" class="pointer">Sign up here</b>
    </p>
</form>

步骤2：修复登录视图逻辑 #

调整代码顺序，修正条件判断，确保登录、注册逻辑正常执行，且登录成功后重定向到dashboard：

修改后的views.py：

def register_login(request):
    form = UserCreationForm()
    if request.method == 'POST':
        # 处理注册请求
        if request.POST.get('submit') == 'Register':
            form = UserCreationForm(request.POST)
            if form.is_valid():
                form.save()
                user = form.cleaned_data['username']
                messages.success(request, f"Account was Created for {user}")
                return redirect('login')
        # 处理登录请求
        elif request.POST.get('submit') == 'Login':
            username = request.POST['username']
            password = request.POST['password']
            user = authenticate(request, username=username, password=password)
            if user is not None:
                login(request, user)
                return redirect('dashboard')  # 登录成功跳转到dashboard
            else:
                messages.error(request, 'Wrong Username or password')
    
    context = {'form': form}
    return render(request, 'login.html', context)
            
class DashboardPageView(TemplateView): 
    template_name = 'dashboard.html'
    def get_context_data(self, **kwargs):
        context = super(DashboardPageView, self).get_context_data(**kwargs)
        context['plot'] = plot1.cumulative_plot()
        return context

额外说明 #

• TemplateView默认仅处理GET请求，无需修改它支持POST，登录逻辑应在专门的登录视图中完成，再通过重定向访问dashboard（GET请求），这符合HTTP最佳实践，还能避免页面刷新时重复提交表单的问题。

内容的提问来源于stack exchange，提问作者dv_confusedcoder