Flask WTF表单:如果用户在SelectMultipleField中选择特定选项，是否可以显示新字段? [英] Flask WTF forms: can a new field be shown if a user selects a specific choice in SelectMultipleField?

问题描述

我刚刚开始使用Flask WTF表单.我可以和他们一起做所有我需要的事情，除了我似乎无法弄清楚一件事.我有一个选择项字段，向用户显示各种选项，如果用户选择其他"，我希望他们描述它们的含义.像这样:

I just started using Flask WTF forms. I can do everything that I need with them except I can't seem to figure out one thing. I have a multiple choice field presenting various options to the user, and if the user selects "other", I want them to describe what they mean. Like this:

 impact = wtforms.SelectMultipleField('What is the expected impact?',
                           choices=[('Sales', 'Sales'),
                                    ('Lift', 'Lift'),
                                    ('Other', 'Other')]

我不知道它是否不是一个具有自己ID的独立字段，而只是数组中的一个成员，是否有可能.你能帮忙吗?

I don't know if it's even possible when it's not an independent field with its own ID but just a member within an array. Could you please help?

编辑

这是我按照下面的建议尝试的操作-从选择或取消选择其他"没有区别的意义上说，它没有用:

here's what I tried following the suggestion below - it didn't work in the sense that selecting or unselecting "Other" makes no difference :

app.py:

app.route('/', methods=['GET', 'POST'])
def home():
     form = MyForm()
     other_enable = False

       if form.validate_on_submit():

          name = form.name.data
          email = form.email.data
          impact1 = form.impact.data
          impact = ''.join(str(e) for e in impact1)

          if ("Other" in impact):
              other_enable = True
          impact_other = form.impact_other.data
          return redirect(url_for('home'))
       return(render_template('home.html', form=form, other_enable=other_enable))

和templates/home.html包含

and templates/home.html contains

{% extends "base.html" %}

{% import "bootstrap/wtf.html" as wtf %}

<center>

  <div id="someid" onchange='myFunction(other_enable)'>{{ wtf.quick_form(form) }}</div>

</center>

{% endblock %}

<script>
     function myFunction(other_enable) {
         var theother = document.getElementById("otherField");

         if (other_enable == true){
            theother.style.display = "block";
        } else {
            theother.style.display = "none";
        }
    }
 </script>

推荐答案

您必须在表单中添加另一个字段，例如 TextField()，并将其设置为 validator.Optional().

You have to add another field in your form like TextField() and make it validator.Optional().

然后使用简单的javascript和 onchange 事件，默认情况下，如果用户选择 Other 显示此字段，则可以 display:none 该字段.

Then with simple javascript and onchange event you can display:none this field by default and if user select Other show it.

最后，如果要强制用户描述他们的意思"，则可以在YourForm类中添加以下方法:

At the end if you want force user to "describe what they mean" you could add in YourForm class this method :

def validate(self):
    """ Add custom validators after default validate
    """
    success = super(YourFormClass, self).validate()

    if 'Other' in self.impact.data and len(self.impact_other.data) < 1:
        success = False
        self.impact.errors.append(gettext('Please fill impact_other field if you had selected "Other"'))

    return success

(假设您创建的其他字段名为 impact_other )

(assuming other field you created is named impact_other)

我稍微修改了validate()函数以使用SelectMultilpleField而不是SelectField

EDIT : I modified slightly my validate() function for working with SelectMultilpleField instead of SelectField

接下来，您不必将 other_enable 变量传递给模板，默认情况下，如果未选择任何内容，则应隐藏 otherField ，因此您需要运行js不仅是onchange，而且页面加载后也是如此.

Next, you don't have to pass other_enable variable to your template, by default if nothing is selected you should hide otherField, so you need to run your js not only onchange but also after page loaded.

如果您在字段 impact 中选择了其他"，则只需检查js函数，如果是，则显示您的字段.您可以查看此问题以获取更多有关检测JS中选定值的帮助:

You just have to check into your js function if 'Other' is selected in your field impact, if yes then show your field. You can look this question for more help at detecting selected values in JS : here

此外，如果表单验证失败，您还必须执行 form = MyForm(request.form)来保存用户输入.

Additionally you have to do form = MyForm(request.form) to save user input if form validate fail.

这篇关于Flask WTF表单:如果用户在SelectMultipleField中选择特定选项，是否可以显示新字段?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！