Question

我在django中创建了一个注册表单，我创建了一个模板标记add_class来创建用户，问题是我收到了这个错误：

'str' object has no attribute 'as_widget'

到

{{ form.username|add_class:'form-control' }}

register_user.html

<form class="form-horizontal" method="POST" action="">
    {% csrf_token %}
    {% if form.errors %}
        <p>Your username and password didn't match. Please try again.</p>
    {% endif %}
    <div class="form-group">
        <div class="col-md-12">
            {{ form.username|add_class:'form-control' }}
        </div>
    </div>
    <div class="form-group">
        <div class="col-md-12">
            {{ form.email|add_class:'form-control' }}
        </div>
    </div>
    <div class="form-group">
        <div class="col-md-12">
            {{ form.password|add_class:'form-control' }}
        </div>
    </div>
    <div class="form-group">
        <div class="col-md-12">
            {{ form.confirm_password|add_class:'form-control' }}
        </div>
    </div>
    <div class="form-group">
        <div class="col-md-12">
            <button type="submit" class="btn btn-info btn-block">Register</button>
            <input type="hidden" name="next" value="{% url 'register_user_success' %}"/>
        </div>
    </div>
</form>

form.py

class UserForm(ModelForm):
    username = forms.CharField(widget=forms.TextInput(attrs={'placeholder': 'Username'}))
    password = forms.CharField(widget=forms.PasswordInput(attrs={'placeholder': 'Password'}))
    email = forms.EmailField(widget=forms.EmailInput(attrs={'placeholder': 'E-mail'}))
    confirm_password = forms.CharField(widget=forms.PasswordInput(attrs={'placeholder': 'Confirm Password'}))

    class Meta:
        model = CustomUser
        fields = ('username', 'email', 'password', 'confirm_password')

    def clean(self):
        cleaned_data = super(UserForm, self).clean()
        password = cleaned_data.get('password')
        confirm_password = cleaned_data.get('confirm_password')
        if password != confirm_password:
            raise forms.ValidationError('Password did not match.')

模板标签：my_filters.py

from django import template

register = template.Library()


@register.filter(name='add_class')
def add_class(value, arg):
    return value.as_widget(attrs={'class': arg})

我已经制作了模板标签，因此我可以从css中添加类。

views.py

def register_user(request):
    data = dict()
    if request.method == 'POST':
        form = UserForm(request.POST)
        if form.is_valid():
            user = form.save(commit=False)
            user.set_password(user.password)
            user.save()
            return redirect('/register_user/success/')
    else:
        data['form'] = UserForm()
    return render(request, 'register_user.html', data)

Answer 1

如果表单无效，则重新呈现模板，但不将表单添加到上下文中。因此，当模板来渲染{{ form.username }}或其他什么时，它找不到它 - 并且当找不到变量时的默认值是使用空字符串。因此，它是传递给过滤器的空字符串，因此是您看到的错误。

解决方案是确保您始终将表单传递到模板中：

else:
    form = UserForm()
return render(request, 'register_user.html', {'form': form})

Django'str'对象没有属性'as_widget'

1 个答案: