Django Benutzerdefinierte Template-Filter mit Registrierung

import re
from django import template
from django.utils.safestring import mark_safe
from django.utils.html import strip_tags
 
register = template.Library()
 
@register.filter(name='truncate_words_html')
def truncate_words_html(value, arg):
    """Truncate HTML string to given word count without breaking tags."""
    from bs4 import BeautifulSoup
    soup = BeautifulSoup(value, 'html.parser')
    text = soup.get_text()
    words = text.split()
    if len(words) <= arg:
        return value
 
    truncated_text = ' '.join(words[:arg]) + '...'
    return mark_safe(truncated_text)
 
@register.filter
def highlight_search(text, search_term):
    """Highlight search term in text with HTML markup."""
    if not search_term:
        return text
    pattern = re.compile(re.escape(search_term), re.IGNORECASE)
    highlighted = pattern.sub(lambda m: f'<mark>{m.group()}</mark>', text)
    return mark_safe(highlighted)
 
@register.filter
def percentage(value, decimals=0):
    """Format number as percentage string."""
    try:
        return f'{float(value) * 100:.{decimals}f}%'
    except (ValueError, TypeError):
        return '0%'
 
@register.filter
def phone_format(value):
    """Format phone number with country code grouping."""
    digits = re.sub(r'\D', '', value)
    if len(digits) == 10:
        return f'({digits[:3]}) {digits[3:6]}-{digits[6:]}'
    elif len(digits) == 11 and digits[0] == '1':
        return f'+1 ({digits[1:4]}) {digits[4:7]}-{digits[7:]}'
    return value
 
@register.inclusion_tag('tags/breadcrumb.html')
def render_breadcrumb(items):
    """Render navigation breadcrumb from list of (url, label) tuples."""
    return {'items': items}
 
@register.simple_tag
def get_menu_items(menu_name, user=None):
    """Retrieve and cache menu items from database."""
    from django.core.cache import cache
    from .models import MenuItem
 
    cache_key = f'menu_{menu_name}'
    items = cache.get(cache_key)
 
    if items is None:
        queryset = MenuItem.objects.filter(menu_name=menu_name, is_active=True)
        if user and not user.is_superuser:
            queryset = queryset.filter(requires_auth=False)
        items = list(queryset.select_related('parent').order_by('sort_order'))
        cache.set(cache_key, items, 3600)
 
    return items