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: handler
( resource parser, string data)
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.
注: 除了函數名稱, 也提供一個包含物件參考的陣列和一個方法名稱。