javascript - 在选择一项其他数据列表应根据第一个数据列表的选定项打开

Question

“我正在制作一个查询模型表单。我已经创建了 datalist 小部件。现在我想要的是，在从 datalist 中选择项目时，应该在第一个 datalist 中选择的项目的基础上再出现一个 datalist。”从下面假设我选择美国，那么美国的一些城市应该出现在新的数据列表中，或者如果我选择中国，中国的一些城市应该出现。

表格.py

from django import forms
from .fields import ListTextWidget

class FormForm(forms.Form):
   data = ('Mexico', 'USA', 'India', 'France')
   char_field_with_list = forms.CharField(required=True)
   char_field_with  = forms.CharField(required=True,widget = ListTextWidget(data_list=data,name='data'))


   def __init__(self, *args, **kwargs):
      _country_list = kwargs.pop('data_list', None)
      super(FormForm, self).__init__(*args, **kwargs)
      self.fields['char_field_with_list'].widget = ListTextWidget(data_list=_country_list, name='country-list')

field.py（创建小部件的地方）来自 django 导入表单

class ListTextWidget(forms.TextInput):
    def __init__(self, data_list, name, *args, **kwargs):
        super(ListTextWidget, self).__init__(*args, **kwargs)
        self._name = name
        self._list = data_list
        self.attrs.update({'list':'list__%s' % self._name})

    def render(self, name, value, attrs=None, renderer=None):
        text_html = super(ListTextWidget, self).render(name, value, attrs=attrs)
        data_list = '<datalist id="list__%s">' % self._name
        for item in self._list:
            data_list += '<option value="%s">' % item
        data_list += '</datalist>'

        return (text_html + data_list)

视图.py

from django.shortcuts import render

# Create your views here.
from .forms import FormForm

def country_form(request):
    # instead of hardcoding a list you could make a query of a model, as long as
    # it has a __str__() method you should be able to display it.
    country_list = ('Mexico', 'USA', 'China', 'France')
    form = FormForm(data_list=country_list)

    return render(request, 'inquiry/inquiry.html', {
        'form': form
    })

标签： javascriptpythonhtmldjangodjango-forms