我正在努力增强网站当前正在使用的单级菜单，以取得显着效果。代码如下（删除了不相关的部分）：
from wagtail.contrib.settings.models import BaseSetting
from modelcluster.models import ClusterableModel
class AbstractCustomMenuItem(models.Model):
"""
Derive from this model to define one or more CustomMenus.
"""
url = models.CharField('URL', max_length=200, blank=True,
help_text='This must be either a fully qualified URL, e.g. https://www.google.com or a local absolute URL, '
'e.g. /admin/login'
)
page = models.ForeignKey('wagtailcore.Page', null=True, blank=True, on_delete=models.CASCADE, related_name='+',
help_text='If a Page is selected, the URL field is ignored. The title of the selected Page will be displayed '
'if the Link Text field is blank.'
)
link_text = models.CharField('Link Text', max_length=50, blank=True)
is_separator = models.BooleanField( 'Separator', default=False,
help_text='Separators are used to visually distinguish different sections of a menu.'
)
panels = [
MultiFieldPanel([
FieldPanel('url', classname='col8 url'), FieldPanel('link_text', classname='col4 link-text'),
], classname='url-and-link-text'),
# This is a bit gnarly, but it was the best way I could find to render the form in a pretty
# way. I'm using MultiFieldPanel and classname='col8' entirely for formatting, rather than organization.
MultiFieldPanel([PageChooserPanel('page')], classname='col8 page-chooser'),
MultiFieldPanel([FieldPanel('is_separator', classname='separator')]),
]
class Meta:
abstract = True
@register_setting(order=1000)
class Settings(BaseSetting, ClusterableModel):
####### FIELD CODE #######
...
####### FORM CODE #######
...
theme_and_menu_panels = [
InlinePanel( 'header_menu_items', label='Header Menu Item',
help_text='You can optionally add a Header Menu to your site, which will appear in the ribbon at the top '
'of the page.'
),
InlinePanel('footer_menu_items', label='Footer Menu Item',
help_text='You can optionally add a Footer Menu to your site, which will appear in the footer.'
),
]
...
edit_handler = TabbedInterface(
[
...
ObjectList(theme_and_menu_panels, heading='Theme and Menus', classname='theme-and-menus'),
...
]
)
class HeaderMenuItem(Orderable, AbstractCustomMenuItem):
"""
This class provides the model for the Header Menu Items that can be added to a Site's settings.
"""
settings = ParentalKey('www.Settings', related_name='header_menu_items', on_delete=models.CASCADE)
class FooterMenuItem(Orderable, AbstractCustomMenuItem):
"""
This class provides the model for the Footer Menu Items that can be added to a Site's settings.
"""
settings = ParentalKey('www.Settings', related_name='footer_menu_items', on_delete=models.CASCADE)
这使我的代码能够分配单独的自定义页眉和页脚菜单。
但是，现在，我需要升级此代码，以允许“标题”菜单项在其下面有其自己的子菜单。而且我发现我基本上可以做与创建MenuItems相同的事情，只需将它们放在HeaderMenuItem类下，而不是Settings下。
因此，我更改了HeaderMenuItem类，并添加了HeaderMenuDropdownItem：
class HeaderMenuItem(Orderable, ClusterableModel, AbstractCustomMenuItem):
"""
This class provides the model for the Header Menu Items that can be added to a Site's settings.
"""
settings = ParentalKey('www.Settings', related_name='header_menu_items', on_delete=models.CASCADE)
panels = [
MultiFieldPanel([
FieldPanel('url', classname='col8 url'), FieldPanel('link_text', classname='col4 link-text'),
], classname='url-and-link-text'),
# This is a bit gnarly, but it was the best way I could find to render the form in a pretty
# way. I'm using MultiFieldPanel and classname='col8' entirely for formatting, rather than organization.
MultiFieldPanel([PageChooserPanel('page')], classname='col8 page-chooser'),
MultiFieldPanel([FieldPanel('is_separator', classname='separator')]),
InlinePanel('dropdown_items', classname='dropdown-items'),
]
class HeaderMenuDropdownItem(Orderable, AbstractCustomMenuItem):
"""
This class provides the model for the Header Menu Dropdown items.
"""
header_menu_item = ParentalKey('www.HeaderMenuItem', related_name='dropdown_items', on_delete=models.CASCADE)
不幸的是，当我加载Wagtail管理页面以编辑Settings类时，现在出现以下异常：
File "/.../django/core/handlers/exception.py" in inner
35. response = get_response(request)
File "/.../django/core/handlers/base.py" in _get_response
128. response = self.process_exception_by_middleware(e, request)
File "/.../django/core/handlers/base.py" in _get_response
126. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/.../django/views/decorators/cache.py" in _cache_controlled
31. response = viewfunc(request, *args, **kw)
File "/.../wagtail/admin/urls/__init__.py" in wrapper
102. return view_func(request, *args, **kwargs)
File "/.../wagtail/admin/decorators.py" in decorated_view
34. return view_func(request, *args, **kwargs)
File "/.../wagtail/contrib/settings/views.py" in edit
83. instance=instance, form=form, request=request)
File "/.../wagtail/admin/edit_handlers.py" in bind_to_instance
152. new.on_instance_bound()
File "/.../wagtail/admin/edit_handlers.py" in on_instance_bound
294. request=self.request))
File "/.../wagtail/admin/edit_handlers.py" in bind_to_instance
152. new.on_instance_bound()
File "/.../wagtail/admin/edit_handlers.py" in on_instance_bound
294. request=self.request))
File "/.../wagtail/admin/edit_handlers.py" in bind_to_instance
152. new.on_instance_bound()
File "/.../wagtail/admin/edit_handlers.py" in on_instance_bound
708. request=self.request))
File "/.../wagtail/admin/edit_handlers.py" in bind_to_instance
152. new.on_instance_bound()
File "/.../wagtail/admin/edit_handlers.py" in on_instance_bound
294. request=self.request))
File "/.../wagtail/admin/edit_handlers.py" in bind_to_instance
152. new.on_instance_bound()
File "/.../wagtail/admin/edit_handlers.py" in on_instance_bound
693. self.formset = self.form.formsets[self.relation_name]
Exception Type: AttributeError at /admin/settings/www/settings/3/
Exception Value: 'HeaderMenuItemForm' object has no attribute 'formsets'
我在做什么错？可以将ParentalKey简单地嵌套在另一个ParentalKey中吗？如果没有，如何实现此多级菜单？也许我从一开始就犯了所有错误？