old_contents: from django import template
  from blanc_basic_events.events.models import Event
  
  register = template.Library()
  
  
  @register.assignment_tag
  def get_events():
      return Event.objects.all().prefetch_related('recurringevent_set', 'recurringeventexclusion_set')
  
new_contents: from django import template
  from blanc_basic_events.events.models import Category, Event
  
  register = template.Library()
  
  
  @register.assignment_tag
  def get_events_categories():
      return Category.objects.all()
  
  
  @register.assignment_tag
  def get_events():
      return Event.objects.all().prefetch_related('recurringevent_set', 'recurringeventexclusion_set')
  
subject: Tag to get all categories