Sets the character data handler function for the XML parser parser. 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 two parameters:
The first parameter, parser, is a reference to the XML parser calling the handler.
The second parameter, data, contains the character data as a string.
If a handler function is set to an empty string, or false, the handler in question is disabled.
True is returned if the handler is set up, false if parser is not a parser.
There is currently no support for object/method handlers. See xml_set_object() for using the XML parser within an object.