Question

我是Django表单，它可以检查表单是否有效：

if form.is_valid(): 
    return HttpResponseRedirect('/thanks/')

但如果它无效，我会错过怎么办？如何返回带有错误消息的表单？我没有在任何例子中看到“其他”。

Answer 1

如果您在表单无效时呈现相同的视图，那么在模板中您可以access the form errors using form.errors。

{% if form.errors %}
    {% for field in form %}
        {% for error in field.errors %}
            <div class="alert alert-danger">
                <strong>{{ error|escape }}</strong>
            </div>
        {% endfor %}
    {% endfor %}
    {% for error in form.non_field_errors %}
        <div class="alert alert-danger">
            <strong>{{ error|escape }}</strong>
        </div>
    {% endfor %}
{% endif %}

一个例子：

def myView(request):
    form = myForm(request.POST or None, request.FILES or None)
    if request.method == 'POST':
        if form.is_valid():
            return HttpResponseRedirect('/thanks/')
    return render_to_response('my_template.html', {'form': form})

Answer 2

<强> views.py

from django.contrib import messages 

def view_name(request):
    if request.method == 'POST':
        form = form_class(request.POST)
        if form.is_valid():
            return HttpResponseRedirect('/thanks'/)
        else:
            messages.error(request, "Error")
return render(request, 'page.html', {'form':form_class()})

如果你想要显示除了无效之外的表格的错误，只需将{{form.as_p}}放入我在下面所做的内容

<强> page.html中

<html>
    <head>
        <script>
            {% if messages %}
                {% for message in messages %}
                    alert(message);
                {% endfor %}
            {% endif %}
        </script>
    </head>
    <body>
        {{form.as_p}}
    </body>
</html>

Answer 3

更新：添加了对表单集错误的更详细描述。

Form.errors组合了所有field和non_field_errors。因此，您可以将html简化为：

模板

if (vec.size() > 2) result.emplace_back(vec[2]);
if (vec.size() > 3) result.emplace_back(vec[3]);

form_tags.py

    {% load form_tags %}

    {% if form.errors %}
    <div class="alert alert-danger alert-dismissible col-12 mx-1" role="alert">
        <div id="form_errors">
            {% for key, value in form.errors.items %}
                <span class="fieldWrapper">
                    {{ key }}:{{ value }}
                </span>
            {% endfor %}
        </div>
        <button type="button" class="close" data-dismiss="alert" aria-label="Close">
            <span aria-hidden="true">&times;</span>
        </button>
    </div>
    {% endif %}


If you want to generalise it you can create a list_errors.html which you include in every form template. It handles form and formset errors:

    {% if form.errors %}
    <div class="alert alert-danger alert-dismissible col-12 mx-1" role="alert">
        <div id="form_errors">

            {% for key, value in form.errors.items %}
                <span class="fieldWrapper">
                    {{ key }}:{{ value }}
                </span>
            {% endfor %}
        </div>
        <button type="button" class="close" data-dismiss="alert" aria-label="Close">
            <span aria-hidden="true">&times;</span>
        </button>
    </div>
    {% elif formset.total_error_count %}
    <div class="alert alert-danger alert-dismissible col-12 mx-1" role="alert">
        <div id="form_errors">
            {% if formset.non_form_errors %}
                {{ formset.non_form_errors }}
            {% endif %}
            {% for form in formset.forms %}
                {% if form.errors %}
                    Form number {{ forloop.counter }}:
                    <ul class="errorlist">
                    {% for key, error in form.errors.items %}
                        <li>{{form.fields|get_label:key}}
                            <ul class="errorlist">
                                <li>{{error}}</li>
                            </ul>
                        </li>
                    {% endfor %}
                    </ul>
                {% endif %}
            {% endfor %}

        </div>
    </div>

    {% endif %}

一个警告：与Formset相比，错误不包括non_field_errors。

Answer 4

def some_view(request):
    if request.method == 'POST':
        form = SomeForm(request.POST)
        if form.is_valid():
            return HttpResponseRedirect('/thanks'/)
    else:
        form = SomeForm()
    return render(request, 'some_form.html', {'form': form})

Answer 5

This answer 是正确的，但有一个问题：未定义字段。如果您有多个字段，您将无法识别哪个字段有错误。

通过此更改，您可以显示字段名称：

{% if form.errors %}
    {% for field in form %}
        {% for error in field.errors %}
            <div class="alert alert-danger">
                <strong>{{ field.label }}</strong><span>{{ error|escape }}</strong>
            </div>
        {% endfor %}
    {% endfor %}
    {% for error in form.non_field_errors %}
        <div class="alert alert-danger">
            <strong>{{ error|escape }}</strong>
        </div>
    {% endfor %}
{% endif %}

Answer 6

@AamirAdnan的答案缺少field.label；另一种显示错误的方式是几行。

{% if form.errors %}
    <!-- Error messaging -->
    <div id="errors">
        <div class="inner">
            <p>There were some errors in the information you entered. Please correct the following:</p>
            <ul>
                {% for field in form %}
                    {% if field.errors %}<li>{{ field.label }}: {{ field.errors|striptags }}</li>{% endif %}
                {% endfor %}
            </ul>
        </div>
    </div>
    <!-- /Error messaging -->
{% endif %}

Answer 7

只需执行以下操作即可，因为初始化表单时，其中还包含表单数据和无效数据：

def some_func(request):
    form = MyForm(request.POST)
    if form.is_valid():
         //other stuff
    return render(request,template_name,{'form':form})

if会在模板中引发错误（如果有的话），但表单数据仍将保持为：

error_demo_here

Answer 8

您可以简单地放置一个标志变量，在这种情况下，已成功。

def preorder_view(request, pk, template_name='preorders/preorder_form.html'):
    is_successed=0
    formset = PreorderHasProductsForm(request.POST)
    client= get_object_or_404(Client, pk=pk)
    if request.method=='POST':
        #populate the form with data from the request
       # formset = PreorderHasProductsForm(request.POST)
        if formset.is_valid():
            is_successed=1
            preorder_date=formset.cleaned_data['preorder_date']
            product=formset.cleaned_data['preorder_has_products']
            return render(request, template_name, {'preorder_date':preorder_date,'product':product,'is_successed':is_successed,'formset':formset})



    return render(request, template_name, {'object':client,'formset':formset})

然后在模板中，您只需将代码放在下面

{%if is_successed == 1 %}
<h1>{{preorder_date}}</h1>
<h2> {{product}}</h2>
{%endif %}

Django Forms：如果无效，请显示包含错误消息的表单

8 个答案: