$autoload_filters
       If there are some filters that you wish to load on every template
       invocation, you can specify them using this variable and Smarty will
       automatically load them for you. The variable is an associative array
       where keys are filter types and values are arrays of the filter
       names. For example:
       
      
      See also
      register_outputfilter(),
      register_prefilter(),
      register_postfilter()
      and
   load_filter()