参数

parser

A reference to the XML parser.

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 three 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.

handler(resource $parser, string $prefix, string $uri)

parser

The first parameter, parser, is a reference to the XML parser calling the handler.

prefix

The prefix is a string used to reference the namespace within an XML object.

uri

Uniform Resource Identifier (URI) of namespace.

If a handler function is set to an empty string, or false, the handler in question is disabled.

注意: 除了函数名，含有对象引用的数组和方法名也可以作为参数。