xml_set_processing_instruction_handler

(PHP 4, PHP 5, PHP 7, PHP 8)

xml_set_processing_instruction_handler — Set up processing instruction (PI) handler

Description

xml_set_processing_instruction_handler(XMLParser $parser, callable $handler): true

Sets the processing instruction (PI) handler function for the XML parser parser.

A processing instruction has the following format:

<?

target data

?>

You can put PHP code into such a tag, but be aware of one limitation: in an XML PI, the PI end tag (?>) can not be quoted, so this character sequence should not appear in the PHP code you embed with PIs in XML documents.If it does, the rest of the PHP code, as well as the "real" PI end tag, will be treated as character data.

Parameters

parser

A reference to the XML parser to set up processing instruction (PI) 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 three parameters:

handler(XMLParser $parser, string $target, string $data)

parser: The first parameter, parser, is a reference to the XML parser calling the handler.
target: The second parameter, target, contains the PI target.
data: The third parameter, data, contains the PI data.

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.

Return Values

Always returns true.

Changelog

Version	Description
8.0.0	`parser` expects an XMLParser instance now; previously, a valid `xml` resource was expected.