如何使用带有 GAE 和 Jinja2 的 WTForms 在字段无效时获得红色边框？

Question

我已经进行了实际工作的验证，我的部分要求是，当字段无效时，无效字段周围应该有红色边框：

<tr><td valign="top">
      <div class="labelform" id="lname">
{% filter capitalize %}{% trans %}name{% endtrans %}{% endfilter %}:
</div></td><td>
  <div class="adinput">
{% if user or current_user %} 
    <input type="text" id="name" name="name" value="{{ current_user.name }}{% if not current_user %}{{ user.nickname() }}{% endif %}" size="35" maxlength="50" readonly/>
  {% else %}
    {{ form.name|safe }}
{% endif %}
{% if form.name.errors %}
        <ul class="errors">{% for error in form.name.errors %}<li>{{ error }}</li>{% endfor %}</ul>
    {% endif %}
  </div>
  </td></tr>

您能告诉我如何在名称字段无效的情况下实现表单字段周围的红色边框吗？这是我的表单类的 python 代码：

class AdForm(Form):

    name = TextField(_('Name'), [validators.Length(min=4, max=50,
                     message=_('Name is required'))])
    title = TextField(_('title'))
    text = TextAreaField(_('Text'), widget=TextArea())
    phonenumber = TextField(_('Phone number'))
    phoneview = BooleanField(_('Display phone number on site'))
    price = TextField(_('Price'))
    password = PasswordField(_('Password'))
    email = TextField(_('Email'))

处理表单的 HTTP POST 的代码是：

...
        form = AdForm(self.request.params)
        if form.validate():
            ad.title = form.title.data
            ad.name = form.name.data
            ad.email = form.email.data
            ad.text = form.text.data
            ad.set_password(form.password.data)
            ad.price = form.price.data
            try:
          form.price.data=form.price.data.replace(',','.').replace(' ', '')
              ad.decimal_price = form.price.data
            except:
              pass
            ad.phoneview = form.phoneview.data
            ad.url = os.environ.get('HTTP_HOST',
                                    os.environ['SERVER_NAME'])
            ad.place = self.request.get('place')
            ad.postaladress = self.request.get('place')
            ad.put()
    else:
        logging.info('form did not validate')
            self.render_jinja(
            'insert_jinja',
            facebook_app_id=facebookconf.FACEBOOK_APP_ID,
            form=form,
            form_url=blobstore.create_upload_url('/upload_form'),
            user=(users.get_current_user() if users.get_current_user() else None),
            user_url=(users.create_logout_url(self.request.uri) if users.get_current_user() else None),
            current_user=self.current_user,
            )
        return
...

你能告诉我当字段无效时我应该如何获得红色边框吗？

谢谢

Answer 1

WTForms 中自定义小部件的文档 建议实现一个自定义小部件将一个类添加到输入元素：

class MyTextInput(TextInput):
    def __init__(self, error_class=u'has_errors'):
        super(MyTextInput, self).__init__()
        self.error_class = error_class

    def __call__(self, field, **kwargs):
        if field.errors:
            c = kwargs.pop('class', '') or kwargs.pop('class_', '')
            kwargs['class'] = u'%s %s' % (self.error_class, c)
        return super(MyTextInput, self).__call__(field, **kwargs)

然后将新的小部件用于您想要此行为的字段：

class AdForm(Form):

    name = TextField(_('Name'), [validators.Length(min=4, max=50,
                     message=_('Name is required'))], widget=MyTextInput())
    title = TextField(_('title'))
    text = TextAreaField(_('Text'), widget=TextArea())
    phonenumber = TextField(_('Phone number'))
    phoneview = BooleanField(_('Display phone number on site'))
    price = TextField(_('Price'))
    password = PasswordField(_('Password'))
    email = TextField(_('Email'))

然后将其添加到 CSS 中：

.has_errors { border: 1px solid #ff0000 }