如何在Django填充下拉列表？

Question

我想使用Django构建一个简单的视图。将出现“customer site's”的下拉列表，然后在选择了一个客户站点后，视图将填充以前选定客户的竞争者的下拉列表。我的问题是第二部分:当我从第一个下拉列表中选择客户并按‘选择’时，页面重新加载，但竞争者下拉列表为空：

我调试了代码，并为竞争者返回了值下拉列表，它们是正确的。我有一个观点：

def index_unify_brands(request):
    class CustomerSiteDropDown(forms.Form):
        customer_site_id = forms.ChoiceField(Site.objects.filter(site_type='customer').exclude(
            crawl_groups='').values_list('id', 'site_name').order_by('site_name'), required=True)

    class OptionsForm(forms.Form):

        competitors_site_ids = forms.ChoiceField()

        def populate_competitors_in_dropdown(self,customer_site_id):
            competitors_ids = get_competitors_positions(customer_site_id)[
                customer_site_id].keys()  # todo: if no competitors

            print competitors_ids
            competitors_for_dropdown = Site.objects.filter(id__in=competitors_ids).exclude(crawl_groups='') \
                .values_list('id', 'site_name').order_by('site_name')
            print competitors_for_dropdown
            self.competitors_site_ids = forms.ChoiceField(competitors_for_dropdown, required=True)

    if request.method == 'POST':
        # received request for a specific customer site id
        customer_dropdown_form = CustomerSiteDropDown(request.POST)
        options_form = OptionsForm(request.POST)
        options_form.populate_competitors_in_dropdown(int(request.POST['customer_site_id']))
        if customer_dropdown_form.is_valid():
            return render_to_response('manage/unify_brands/unify_brands.html',
                                      {'customer_dropdown_form': customer_dropdown_form,
                                       'options_form': options_form},
                                      context_instance=RequestContext(request)
                                      )
    else:

        customer_dropdown_form = CustomerSiteDropDown()
        return render_to_response('manage/unify_brands/unify_brands.html',
                                  {'customer_dropdown_form': customer_dropdown_form},
                                  context_instance=RequestContext(request))

当我实例化OptionsForm对象时，options_form.populate_competitors_in_dropdown(....)方法似乎不会更改由competitors_site_ids变量表示的对象中的下拉列表。

知道我在这里做错了什么吗？

Answer 1

在您的表单中，self.competitors_site_ids与此无关。您需要分配给self.fields['competitors_site_ids']。

而且，这段代码应该在__init__中，而不是单独的方法中。