(PHP 4, PHP 5, PHP 7, PHP 8)
xml_set_default_handler — Set up default handler
   Sets the default handler function for the XML parser
   parser.
  
parserThe XML parser.
handler
 If null or an empty string is passed, the handler is reset to its default state.
 If handler is a callable,
 the callable is set as the handler.
 If handler is a string,
 it can be the name of a method of an object set with
 xml_set_object().
The signature of the handler must be:
parserdata
         data contains the character data.
           This may be the XML declaration, document type declaration,
           entities or other data for which no other handler exists.
          
         
   Always returns true.