(PHP 4, PHP 5)
xml_set_external_entity_ref_handler — Set up external entity reference handler
   Sets the external entity reference handler function for the XML parser
   parser.
  
parserA reference to the XML parser to set up external entity reference handler function.
handler
       handler is a string containing the name of a
       function that must exist when xml_parse() is called
       for parser.
      
       The function named by handler must accept
       five parameters, and should return an integer value.If the
       value returned from the handler is FALSE (which it will be if no
       value is returned), the XML parser will stop parsing and
       xml_get_error_code() will return
       XML_ERROR_EXTERNAL_ENTITY_HANDLING.
       
$parser
        , string $open_entity_names
        , string $base
        , string $system_id
        , string $public_id
        )parseropen_entity_namesopen_entity_names, is a
           space-separated list of the names of the entities that are open for
           the parse of this entity (including the name of the referenced
           entity).
          
         basesystem_id) of the external entity.Currently
           this parameter will always be set to an empty string.
          
         system_idsystem_id, is the
           system identifier as specified in the entity declaration.
          
         public_idpublic_id, is the
           public identifier as specified in the entity declaration, or
           an empty string if none was specified; the whitespace in the
           public identifier will have been normalized as required by
           the XML spec.
          
         
       If a handler function is set to an empty string, or FALSE, the handler
       in question is disabled.
      
Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.
   Returns TRUE on success or FALSE on failure.