ProcessingInstruction: ProcessingInstruction() constructor

The ProcessingInstruction() constructor creates a new ProcessingInstruction object instance.

Syntax

new ProcessingInstruction(target, data)

Parameters

target: A string representing the type of event.
data: A string containing any information the processing instruction should carry, after the target. The data is up to you, but it can't contain ?>, since that closes the processing instruction.

Return value

Processing instructions are, as the name suggests, are instructions about how to process the document. They can include stylesheets for XML documents, placeholders for HTML documents, or other processing instructions.

A new ProcessingInstruction object, if used internally by the browser.

Developers cannot use the ProcessingInstruction() constructor directly to create a new ProcessingInstruction instance, and must use the document.createProcessingInstruction() method instead. Attempting to use the ProcessingInstruction() constructor directly results in an "illegal constructor" error.

Exceptions

InvalidCharacterError DOMException

Thrown if either of the following are true:

The target value is not a valid XML name; for example, it starts with a number, hyphen, or period, or contains characters other than alphanumeric characters, underscores, hyphens, or periods.
The closing processing instruction sequence (?>) is part of the data value.

TypeError

Thrown with the message "Illegal constructor" when used directly.

Examples

const doc = new DOMParser().parseFromString("<foo />", "application/xml");
const pi = doc.createProcessingInstruction(
  "xml-stylesheet",
  'href="mycss.css"',
);