text: 
  
  from django import template
  
  register = template.Library()
  
  @register.filter
  def multiply(value, arg):
      return value*arg
  
  @register.filter
  def to_class_name(value):
      return value.__class__.__name__
  
  @register.simple_tag
  def url_replace(request, field, value):
      """Puts a GET parameter into a url?"""
      dict_ = request.GET.copy()
      dict_[field] = value
      return dict_.urlencode()
  
  @register.simple_tag
  def order_by(request, field, attr):
  
      dict_ = request.GET.copy()
  
      if dict_.__contains__(field) and dict_[field] == attr:
          if not dict_[field].startswith("-"):
              dict_[field] = "-" + attr
          else:
              dict_[field] = attr
      else:
          dict_[field] = attr
  
      return dict_.urlencode()
  
  @register.filter
  def singlequot(value):
      """Removes all values of arg from the given string"""
      return (value or '').replace('"', "'")
  