How the Transformation Process Gets Started

This section describes transformation process starting logic - an XSL processor will automatically start to perform transformation on the root element.

After learned "template" and "apply-templates" elements, we can now look at how the XSLT transformation process gets started, and in which order elements in the source XML document get processed.

Let's go back to our "Hello world!" XSLT example. Here is the source XML document, hello_xsl.xml:

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="hello.xsl"?>
<p>Hello world!</p>

Here is the XSLT stylesheet, hello.xsl:

<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:template match="p">Hello world.! - From hello.xsl.</xsl:template>
</xsl:stylesheet>

Here is the transformation result document:

Hello world! - From hello.xsl.

Question: What is the trigger to perform transformation on element "p"? Or who requested to apply transformation template on element "p"? My guess is that the XSLT engine, or XSL processor, automatically starts the transformation on the root element, which is "p" in our example.

Rule: XSL processors automatically start to apply transformation on the root element. The following XSL statements is not needed, also not allowed, directly under the "stylesheet" element:

<xsl:apply-templates select="root_element_name"/>

Table of Contents

 About This Book

 Introduction of XML (eXtensible Markup Language)

 XML File Syntax

 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

 What Is XSLT (XSL Transformations)

 "stylesheet" - The Stylesheet Declaration Element

 "template" - The Template Declaration Element

 Including Literal XML Elements in Templates

 "apply-templates" - The Child Transformation Call Element

How the Transformation Process Gets Started

 Default Transformation Template

 XML Element Transformation Chains

 XML Element Transformation Chains - Complex Example

 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