The <?xml ...?> Processing Instruction

XML Tutorials - Herong's Tutorial Examples

∟The <?xml ...?> Processing Instruction

This section describes the 'xml' processing instruction, which is required at the top of XML files. 'xml' processing instruction must have the 'version' attribute.

Every XML file must contain one "xml" processing instruction at the beginning of the file to declare that this file is an XML file.

There is one required attribute for the "xml" processing instruction: version="n", indicating the version number of the XML standard.

Valid attributes of the "xml" processing instruction are:

version - A required attribute that specifies the version of the XML standard this XML file conforms to. Currently, there are two versions of the XML standard available: 1.0 and 1.1.
encoding - An optional attribute that specifies the character encoding schema used in this XML file. Currently, there are many encodings supported by most XML applications: UTF-8, UTF-16, ISO-10646-UCS-2, ISO-10646-UCS-4, ISO-8859-1, ..., ISO-8859-9, ISO-2022-JP, Shift_JIS, EUC-JP.
standalone - An optional attribute that specifies if this XML file is self-contained or not. If standalone="yes", this XML file is self-contained. If standalone="no", this XML file is not self-contained. A self-contained XML file can be safely processed without reading any additional markup declarations from external files.

Here is an example XML file that has all 3 attributes included in the "xml" processing instruction:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<p>Hello world!</p>

In this tutorial book, we will be learning XML version 1.0 first. XML version 1.1 tutorials are added at the end.

Table of Contents

About This Book

Introduction of XML (eXtensible Markup Language)

►XML File Syntax

Types of Information in XML Files

XML File Syntax Rules

►The <?xml ...?> Processing Instruction

dictionary.xml - A Simple XML Sample File

XML File Browsers

XML-JSON Document Conversion

DOM (Document Object Model) Programming Interface

SAX (Simple API for XML) Programming Interface

DTD (Document Type Definition) Introduction

Syntaxes of DTD Statements

Validating an XML Document against the Specified DTD Document Type

XSD (XML Schema Definition) Introduction

Syntaxes of XSD Statements

Validating XML Documents Against Specified XML Schemas

XSL (Extensible Stylesheet Language) Introduction

Java Implementation of XSLT

XSLT (XSL Transformations) Introduction

XPath (XML Path) Language

XSLT Elements as Programming Statements

Control and Generate XML Element in the Result

PHP Extensions for XML Manipulation

Processing XML with Python Scripts

XML Notepad - XML Editor

XML Tools Plugin for Notepad++

XML Plugin Packages for Atom Editor

XML 1.1 Changes and Parsing Examples

Archived Tutorials

References

Full Version in PDF/EPUB