Document: createProcessingInstruction() method

The createProcessingInstruction() method of the Document interface creates a new ProcessingInstruction object and returns it.

Syntax

createProcessingInstruction(target, data)

Parameters

target

A string containing the first part of the processing instruction (i.e., <?target … ?>)

data

A string containing any information the processing instruction should carry, after the target. The data can contain any character pattern, except that it can't contain ?>, since that closes the processing instruction.

Return value

• A ProcessingInstruction node.

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 included as part of the data value.

Description

The createProcessingInstruction() method creates a new processing instruction. The new node will usually be inserted into a document to accomplish a task with it, using a method such as node.insertBefore.

Initially, ProcessingInstruction nodes were only supported in XML documents, not in HTML documents. In non-supporting browsers, a processing instruction will be interpreted as a comment and represented as a Comment object in the DOM tree.

Examples

Basic usage

This example creates an <xml-stylesheet> processing instruction and adds it to the top of an example XML document.

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

doc.insertBefore(pi, doc.firstChild);

console.log(new XMLSerializer().serializeToString(doc));
// Displays: <?xml-stylesheet href="mycss.css" type="text/css"?><foo/>

Specifications

• DOM