code: def modify_content(request, page_id, content_type, language_id):
      
      page = get_object_or_404(Page, pk=page_id)
      perm = request.user.has_perm('pages.change_page')
      if perm and request.method == 'POST':
          content = request.POST.get('content', False)
          if not content:
              raise Http404
          page = Page.objects.get(pk=page_id)
          if settings.PAGE_CONTENT_REVISION:
              Content.objects.create_content_if_changed(page, language_id,
                                                        content_type, content)
          else:
              Content.objects.set_or_create_content(page, language_id,
                                                    content_type, content)
          page.invalidate()
          # to update last modification date
          page.save()
  
          return HttpResponse('ok')
      raise Http404
docs: Modify the content of a page.