title: Wagtail filter page-childs-elements on the basis of logged-in user's permissions
body: <p>I am working on a small site using Wagtail. This site is all about a "mainpage" and several "subpages". So far it is pretty simple! But, depending on what group the user (not admin) is in, the right subpages should show up! </p>
  
  <p>See the following setup (minimized), to get an idea of what I am talking about. </p>
  
  <p>If I set permissions on ToolKitPart (like requiring explicit user-login and group-membership), then the following is happening:</p>
  
  <ul>
  <li><p>when going to the page using the fully qualified path, the user is requested to login and, in the case of insufficient rights, the user will not see the content!</p></li>
  <li><p>when going to the ToolkitIndex-Page, all children are displayed, including the ones the user never should see, without the need to be logged in or being a member of a certain group.</p>
  
  <pre><code>class ToolkitIndex(Page):
      def get_context(self, request):
          # Update context to include only published posts, ordered by reverse-chron
          context = super().get_context(request)
          blogpages = self.get_children().live().order_by('-first_published_at')
          context['pages'] = blogpages    
          return context
  
  class ToolkitPart(Page):
      body = StreamField([
          ('staff', MpStaff()),
          ('news', MpNews()),
          ('stuff', MpStuff()),
          ('teditor', blocks.RichTextBlock()),
          ('reditor', blocks.RawHTMLBlock()),
      ], blank=True)
  
      content_panels = Page.content_panels + [
          StreamFieldPanel('body'),
      ]
  
  class MpNews(blocks.StructBlock):
      head = blocks.TextBlock(required=True, help_text='Schlagzeile')
      lead = blocks.TextBlock(required=False, help_text='Einleitung')
      body = blocks.RichTextBlock(required=True, help_text='Inhalt')
      image = ImageChooserBlock(required=False)
  
      type = blocks.ChoiceBlock(
          choices=[('default', 'Standard'),
               ('highlight', 'Hervorgehoben'),
               ], required=True)
  
      class Meta:
          template = 'home/mparts/toolkit_news.html'
          icon = 'code'
  </code></pre></li>
  </ul>
  
  <p>Any idea how to solve this?</p>