将当前过滤器选择提供给 Django 中的另一个自定义 SimpleListFilter

我正在尝试更改一个过滤器的提示，以响应另一个过滤器中所做的当前选择。我非常不知道如何将 AttributeCategoryFilter 的当前选定值传递到 AttributeFilter 中。我正在使用 Django 1.4-dev。试图弄清楚我是否应该使用RelatedFieldListFilter来达到这个目的。看起来这些功能还很年轻，目前还没有任何例子。

    class AttributeCategoryFilter(SimpleListFilter):
        title = _('Attribute Category')
        parameter_name = 'attribute_category'
        def lookups(self, request, model_admin):
            attributes = Attribute.objects.filter(parent_attribute=None)
            prompts = []
            for attribute in attributes:
                prompts.append((attribute.title, _(str(attribute.title))))
            return prompts
        def queryset(self, request, queryset):
            if self.value():
                return queryset.filter(attribute__category=self.value())
            else:
                return queryset


    class AttributeFilter(SimpleListFilter):
        title = _('Attribute Title')
        parameter_name = 'attribute_title'
        def lookups(self, request, model_admin):
            desired_category =  # Needs to be a reference to the selected value in the AttributeCategoryFilter above
            attributes = Attribute.objects.filter(category=desired_category).exclude(parent_attribute=None)
            prompts = []
            for attribute in attributes:
                prompts.append((attribute.title, _(str(attribute.title))))
            return prompts
        def queryset(self, request, queryset):
            if self.value():
                return queryset.filter(attribute__title=self.value())
            else:
                return queryset


    class ValueAdmin(admin.ModelAdmin):
        list_display = ('package', 'attribute', 'presence', 'text', 'modified', 'created')
        list_filter = ('package', AttributeCategoryFilter, AttributeFilter, 'presence', 
            'attribute__admin_approved', 'attribute__dtype', 'modified')
        search_fields = ('package', 'attribute', 'text')
        list_display_links = ('package', )
        list_editable = ('presence', 'text')
        list_per_page = 20000
    admin.site.register(Value, ValueAdmin)   

这对我有用...“TypeListFilter”仅在使用“类别”过滤器后才可见，然后显示属于所选类别“subTypeOf”的所有条目。进一步的“特殊情况”黑客确保当用户选择另一个类别时过滤器消失。 “_class”参数增加了一些额外的灵活性。我将相同的过滤器与不同但相关的 Type 类一起使用，只需覆盖这一参数。只需将其替换为您要过滤的 admin.Model 类即可。

class TypeListFilter( admin.SimpleListFilter):
    """
    Provide filter for DnaComponentType (the actual "second level" type).

    This filter has one cosmetic problem, which is that it's setting is not
    automatically deleted if the category filter is changed. I tried but the
    request and queryset are all immutable. Instead, the queryset method is 
    checking for any missmatch between category and filter name and filtering
    is ignored if the category name doesn't match the current subType name.
    """
    title = 'Type'
    parameter_name = 'type'

    _class = None

    def lookups(self, request, model_admin):
        """
        Returns a list of tuples. The first element in each
        tuple is the coded value for the option that will
        appear in the URL query. The second element is the
        human-readable name for the option that will appear
        in the right sidebar.
        """
        if not u'category' in request.GET:
            return ()

        category_name = request.GET[u'category']
        types = self._class.objects.filter(subTypeOf__name=category_name)
        return ( (t.name, t.name) for t in types )

    def queryset(self, request, queryset):
        """
        Returns the filtered queryset based on the value
        provided in the query string and retrievable via
        `self.value()`.
        """
        if not u'category' in request.GET:
            return queryset

        category = request.GET[u'category']
        subtypes = self._class.objects.filter(subTypeOf__name=category)

        r = queryset.filter(componentType__subTypeOf__name=category)

        if not self.value():
            return r

        ## special case: missmatch between subtype and category
        ## which happens after switching the category
        if len(subtypes.filter(name=self.value())) == 0:
            return r

        return r.filter(componentType__name=self.value())