text: """general utility functions for HTML Map templates"""
  
  from __future__ import absolute_import
  
  
  def safe_quotes(text, escape_single_quotes=False):
      """htmlify string"""
      if isinstance(text, str):
          safe_text = text.replace('"', "&quot;")
          if escape_single_quotes:
              safe_text = safe_text.replace("'", "&#92;'")
          return safe_text.replace('True', 'true')
      return text
  
  
  def quote_filter(value):
      return safe_quotes(value.unescape())
  
  
  def iframe_size_filter(value):
      if isinstance(value, str):
          return value
  
      return '%spx;' % value
  
  
  def clear_none_filter(value):
      return dict(filter(lambda item: item[1] is not None, value.items()))
  