XML Data Processing and Transformation ดร. มารุต บูรณรัช...

XML Data Processing and Transformationดร.มาร�ต บูรณร�ช [email protected]

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Outline

XML Data Processing APIs SAX (Simple API for XML) DOM (Document Object Model)

XSL Tranformation (XSLT) Language

2

XML Data Processing APIs: DOM and SAX

Slides adapted from Pekka Kilpeläinen, Universiry of Kuopio, Finland- http://www.cs.uku.fi/~kilpelai/RDK02/

XML Document Parsers

Every XML application contains a parser XML editors, XML browsers XML data transformation systems

XML parsers are becoming standard tools of application development frameworks JDK v. 1.4 contains JAXP, with its default parser

(Apache Crimson) JAXP = Java API for XML Processing

4

Tasks of an XML Parser

Document instance decomposition Elements, Attributes, Text, Processing instructions,

Entities, ... Verification

Well-formedness checking syntactical correctness of XML markup

Validation (against a DTD or Schema) Access to contents of the DTD

Not always supported

5

XML Processing APIs

There are two major types of XML APIs Event-based API

The application implements handlers to deal with the various events

Simple API for XML (SAX)

Tree-based API Compiles an XML document into an internal tree structure

and allows an application to navigate that tree Document Object Model (DOM)

6

SAX – an Event-based API

Event-based API

Application implements a set of callback methods for handling parse events parser notifies the application by method calls method parameters qualify events further

element type name names and values of attributes values of content strings, …

8

Event-based API (2)

ApplicationApplication

SGML/XML ParserSGML/XML Parser

CommandCommandline callline call ESISESIS

StreamStream

<A<A </A></A>Hi!Hi!

(A(A

i="1"i="1" >>

Ai CDATA 1Ai CDATA 1

-Hi!-Hi!)A)A

ESIS = Element Structure Information Set 9

An event call-back application

Application Main Application Main RoutineRoutine

startDocument()startDocument()

startElement()startElement()

characters()characters()

Parse()Parse()

Callback

Callback

Routines

Routines

endElement()endElement() <A i="1"><A i="1"> </A></A>Hi!Hi!

"A",[i="1"]"A",[i="1"]

"Hi!""Hi!"

"A""A"<?xml version='1.0'?><?xml version='1.0'?>

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SAX Event Call-back API

• A de-facto industry standardo Not an official standard or W3C

Recommendationo Developed by members of the xml-dev mailing

list

• Supported directly by major XML parserso Most are Java based and free: Sun JAXP, IBM

XML4J, Oracle's XML Parser for Java, Apache Xerces; MSXML (in IE 5), James Clark's XP

11

SAX 2.0 Interfaces

SAX interfaces: Parser-to-application (or call-back) interfaces

to attach special behaviour to parser-generated events

Application-to-parser to use the parser

Auxiliary to manipulate parser-provided information

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SAX Processing Example

<?xml version="1.0" encoding="ISO-8859-1"?><db>

<person idnum="1234"><last>Kilpeläinen</last><first>Pekka</first></person><person idnum="5678"><last>Möttönen</last><first>Matti</first></person><person idnum="9012"><last>Möttönen</last><first>Maija</first></person><person idnum="3456"><last>Römppänen</last><first>Maija</first></person>

</db>

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SAX Processing Example (2)

Task: Format the document as a list like this:

Pekka Kilpeläinen (1234)Matti Möttönen (5678)Maija Möttönen (9012)Maija Römppänen (3456)

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SAX Processing Example (3)

Solution: using event-based processing: at the start of a person, record the idnum (e.g.,

1234) keep track of starts and ends of elements last and first, in order to record content of those elements (e.g., "Kilpeläinen" and "Pekka")

at the end of each person, output the collected data

15

SAX Programming Example Application: Begin by importing relevant classes:

import org.xml.sax.XMLReader;import org.xml.sax.Attributes;import org.xml.sax.ContentHandler;

//Default (no-op) implementation of//interface ContentHandler:import org.xml.sax.helpers.DefaultHandler;

// SUN JAXP used to obtain a SAX parser:import javax.xml.parsers.*;

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SAX Programming Example (2) Define a class to implement relevant call-back

methods:

public class SAXDBApp extends DefaultHandler{// Flags to remember element context:private boolean InFirst = false,

InLast = false;// Storage for element contents and // attribute values:

private String FirstName, LastName, IdNum;

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SAX Programming Example (3) Call-back methods: record the start of first and last

elements, and the idnum attribute of a person:public void startElement (

String namespaceURI, String localName, String rawName, Attributes atts) {

if (localName.equals("first")) InFirst = true;

if (localName.equals("last")) InLast = true;

if (localName.equals("person")) IdNum = atts.getValue("idnum");

} // startElement

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SAX Programming Example (4) Call-back methods continue: Record the text content of

elements first and last in corresponding variables:

public void characters (char ch[], int start, int length) {

if (InFirst) FirstName = new String(ch, start, length);

if (InLast) LastName = new String(ch, start, length);

} // characters

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SAX Programming Example (5) Call-back methods continue: at an exit from person,

output the collected data:

public void endElement(String namespaceURI, String localName, String qName) {

if (localName.equals("person"))

System.out.println(FirstName + " " + LastName + " (" + IdNum + ")" );

//Update the context flags:

if (localName.equals("first"))

InFirst = false;

//(Correspondingly for "last" and InLast)

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SAX Programming Example (6) Application main method:public static void main (String args[])

throws Exception {// Instantiate an XMLReader (from JAXP // SAXParserFactory): SAXParserFactory spf =

SAXParserFactory.newInstance(); try {

SAXParser saxParser = spf.newSAXParser(); XMLReader xmlReader =

saxParser.getXMLReader();

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SAX Processing Example (9) Main method continues:// Instantiate and pass a new // ContentHandler to xmlReader:

ContentHandler handler = new SAXDBApp(); xmlReader.setContentHandler(handler); for (int i = 0; i < args.length; i++) { xmlReader.parse(args[i]); }

} catch (Exception e) {System.err.println(e.getMessage());

System.exit(1);};

} // main

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DOM – a Tree-based API

Object Model Interfaces

Application interacts with an object-oriented representation of the parser the document parse tree consisting of objects like

Document, Element, Attribute, Text, … Abstraction level higher than in event based

interfaces; more powerful access to descendants, following siblings, …

Disadvantage: Higher memory consumption

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An Object-Model Based Application

ApplicationApplication

ParserParserObjectObject

In-Memory In-Memory Document Document

RepresentationRepresentation

ParseParse

Access/Access/ModifyModify

BuildBuild

DocumentDocument

i=1i=1AA

"Hi!""Hi!"

<A i="1"><A i="1"> </A></A>Hi!Hi!

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Document Object Model (DOM)

To provide uniform access to structured documents in diverse applications (parsers, browsers, editors, databases)

Overview of W3C DOM Specification Level 1, W3C Rec, Oct. 1998 Level 2, W3C Rec, Nov. 2000 Level 3, W3C Rec, Apr 2004

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Document Object Model (DOM) (2)

An object-based, language-neutral API for XML and HTML documents

allows programs and scripts to build documents, navigate their structure, add, modify or delete elements and content

Provides a foundation for developing, querying, filtering, transformation, rendering etc.

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DOM structure model

Based on O-O concepts: methods (to access or change object’s state) interfaces (declaration of a set of methods) objects (encapsulation of data and methods)

Roughly similar to the XSLT/XPath data model a parse tree

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29

invoiceinvoice

invoicepageinvoicepage

namename

addresseeaddressee

addressdataaddressdata

addressaddress

form="00"form="00"type="estimatedbill"type="estimatedbill"

Leila LaskuprinttiLeila Laskuprintti streetaddressstreetaddress postofficepostoffice

70460 KUOPIO70460 KUOPIOPyynpolku 1Pyynpolku 1

<invoice><invoice> <invoicepage form="00" <invoicepage form="00" type="estimatedbill">type="estimatedbill"> <addressee><addressee> <addressdata><addressdata> <name>Leila Laskuprintti</name><name>Leila Laskuprintti</name> <address><address> <streetaddress>Pyynpolku 1<streetaddress>Pyynpolku 1 </streetaddress></streetaddress> <postoffice>70460 KUOPIO<postoffice>70460 KUOPIO </postoffice></postoffice> </address></address> </addressdata></addressdata> </addressee> ...</addressee> ...

DocumentDocument

ElementElement

NamedNodeMapNamedNodeMap

TextText

DOM structure DOM structure modelmodel

Structure of DOM Level 1

I: DOM Core Interfaces Fundamental interfaces

basic interfaces to structured documents Extended interfaces

XML specific: CDATASection, DocumentType, Notation, Entity, EntityReference, ProcessingInstruction

II: DOM HTML Interfaces more convenient to access HTML documents

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DOM Level 2 Level 1: basic representation and

manipulation of document structure and content (No access to the contents of a DTD)

DOM Level 2 adds support for namespaces accessing elements by ID attribute values optional features

interfaces to document views and style sheets an event model (user actions on elements) methods for traversing the document tree and manipulating

regions of document (e.g., selected by the user of an editor)

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DOM(core)

The primary types of objects : Node

Base type of most objects Element

Represents the elements in a document DocFragment

Root node of a document fragment Document

Represents the root node of a standalone document

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DOM(core)

The following are auxiliary types of objects : NodeIterator

Used for iterating over a set of nodes specified by filter AttributeList

Represents a collection of attribute objects, indexed by attribute name

Attribute Represents an attribute in an element object

DocumentContext A repository for metadata about a document

DOM Provides instance-independent document operations

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DOM interfaces: NodeDOM interfaces: Node

invoice

invoicepage

name

addressee

addressdata

address

form="00"type="estimatedbill"

Leila Laskuprintti streetaddress postoffice

70460 KUOPIOPyynpolku 1

NodeNodegetNodeTypegetNodeTypegetNodeValuegetNodeValuegetOwnerDocumentgetOwnerDocumentgetParentNodegetParentNodehasChildNodeshasChildNodes getChildNodesgetChildNodesgetFirstChildgetFirstChildgetLastChildgetLastChildgetPreviousSiblinggetPreviousSiblinggetNextSiblinggetNextSiblinghasAttributeshasAttributes getAttributesgetAttributesappendChild(newChild)appendChild(newChild)insertBefore(newChild,refChild)insertBefore(newChild,refChild)replaceChild(newChild,oldChild)replaceChild(newChild,oldChild)removeChild(oldChild)removeChild(oldChild)

DocumentDocument

ElementElement


TextText

Object Creation in DOM Each DOM object X lives in the context of a Document: X.getOwnerDocument()

Objects implementing interface X are created by factory methods

D.createX(…) ,where D is a Document object. E.g: createElement("A"), createAttribute("href"), createTextNode("Hello!")

Creation and persistent saving of Documents left to be specified by implementations

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invoiceinvoice


namename

addresseeaddressee


addressaddress




DocumentDocumentgetDocumentElementgetDocumentElementcreateAttribute(name)createAttribute(name)createElement(tagName)createElement(tagName)createTextNode(data)createTextNode(data)getDocType()getDocType()getElementById(IdVal)getElementById(IdVal)

NodeNode

DocumentDocument

ElementElement


TextText

DOM interfaces: DocumentDOM interfaces: Document

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DOM interfaces: ElementDOM interfaces: Element

invoiceinvoice


namename

addresseeaddressee


addressaddress




ElementElementgetTagNamegetTagNamegetAttributeNode(name)getAttributeNode(name)setAttributeNode(attr)setAttributeNode(attr)removeAttribute(name)removeAttribute(name)getElementsByTagName(name)getElementsByTagName(name)hasAttribute(name)hasAttribute(name)

NodeNode

DocumentDocument

ElementElement


TextText

Additional Core Interfaces NodeList for ordered lists of nodes

e.g. from Node.getChildNodes() or Element.getElementsByTagName("name")

all descendant elements of type "name" in document order (wild-card "*"matches any element type)

• Accessing a specific node, or iterating over Accessing a specific node, or iterating over all nodes of a all nodes of a NodeListNodeList::– E.g. Java code to process all children:E.g. Java code to process all children:for for (i=0;(i=0;

i<node.getChildNodes().getLength(); i<node.getChildNodes().getLength();

i++) i++)

process(node.getChildNodes().item(i));process(node.getChildNodes().item(i));38

Additional Core Interfaces (2)

NamedNodeMap for unordered sets of nodes accessed by their name: e.g. from Node.getAttributes()

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DOM: Implementations

Java-based parsers e.g. IBM XML4J, Apache Xerces, Apache Crimson

MS IE5 browser: COM programming interfaces for C/C++ and MS Visual Basic, ActiveX object programming interfaces for script languages

XML::DOM (Perl implementation of DOM Level 1) etc.

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A Java-DOM Example

A stand-alone toy application BuildXml either creates a new db document with two person elements, or adds them to an existing db document

based on the example in Sect. 8.6 of Deitel et al: XML - How to program

Use DOM support in Sun JAXP

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Code of BuildXml (1) Begin by importing necessary packages:

import java.io.*;

import org.w3c.dom.*;

import org.xml.sax.*;

import javax.xml.parsers.*;

// Native (parse and write) methods of the

// JAXP 1.1 default parser (Apache Crimson):

import org.apache.crimson.tree.XmlDocument;

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Code of BuildXml (2) Class for modifying the document in file fileName:

public class BuildXml { private Document document;

public BuildXml(String fileName) { File docFile = new File(fileName); Element root = null; // doc root element

// Obtain a SAX-based parser: DocumentBuilderFactory factory =

DocumentBuilderFactory.newInstance();

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Code of BuildXml (3)

try { // to get a new DocumentBuilder: documentBuilder builder =

factory.newInstance();

if (!docFile.exists()) { //create new doc document = builder.newDocument();

// add a comment: Comment comment =

document.createComment( "A simple personnel

list"); document.appendChild(comment);

// Create the root element: root = document.createElement("db");

document.appendChild(root); 44


… or if docFile already exists:

} else { // access an existing doc try { // to parse docFile

document = builder.parse(docFile);root = document.getDocumentElement();

} catch (SAXException se) {System.err.println("Error: " +

se.getMessage() );System.exit(1);

}

/* A similar catch for a possible IOException */

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Create and add two child elements to root:

Node personNode = createPersonNode(document, "1234",

"Pekka", "Kilpeläinen");

root.appendChild(personNode);

personNode = createPersonNode(document, "5678",

"Irma", "Könönen");

root.appendChild(personNode);

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Finally, store the result document:

try { // to write the // XML document to file fileName

((XmlDocument) document).write( new FileOutputStream(fileName));

} catch ( IOException ioe ) {

ioe.printStackTrace(); }

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Methods to create person elements

public Node createPersonNode(Document document, String idNum, String fName, String lName)

{ Element person =

document.createElement("person"); person.setAttribute("idnum", idNum); Element firstName =

document. createElement("first");person.appendChild(firstName);

firstName. appendChild( document. createTextNode(fName) );

/* … similarly for a lastName */ return person;

} 48

The main method for BuildXml

public static void main(String args[]){ if (args.length > 0) {

String fileName = args[0]; BuildXml buildXml = new

BuildXml(fileName); } else {

System.err.println("Give filename as argument");

};} // main

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Summary of XML APIs

XML processors make the structure and contents of XML documents available to applications through APIs

Event-based APIs notify application through parsing events e.g., the SAX call-back interfaces

Object-model (or tree) based APIs provide a full parse tree

e.g, DOM, W3C Recommendation more convenient, but may require too much

resources with very large documents Major parsers support both SAX and DOM

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XSL Transformation(XSLT)

Slides taken & adapted from -Grigoris Antoniou & Frank van Harmelen, A Semantic Web Primer - Chapter 2 - Structured Web Documents in XML-Andy Clark, XML Style Sheets, http://people.apache.org/~andyc/xml/present/

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Displaying XML Documents

<author><name>Grigoris Antoniou</name><affiliation>University of Bremen</affiliation><email>[email protected]</email>

</author>

may be displayed in different ways: Grigoris Antoniou Grigoris AntoniouUniversity of Bremen University of [email protected] [email protected]

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Style Sheets

Style sheets can be written in various languagesE.g. CSS2 (cascading style sheets level 2)XSL (extensible stylesheet language)

XSL includes a transformation language (XSLT)a formatting languageBoth are XML applications

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XSL Transformations (XSLT)

XSLT specifies rules with which an input XML document is transformed to another XML document an HTML document plain text

The output document may use the same DTD or schema, or a completely different vocabulary

XSLT can be used independently of the formatting language

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XSLT (2)

Move data and metadata from one XML representation to another

XSLT is chosen when applications that use different DTDs or schemas need to communicate

XSLT can be used for machine processing of content without any regard to displaying the information for people to read.

In the following example, we use XSLT only to display XML documents

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XSLT Transformation into HTML <xsl:template match="/author">

<html><head><title>An author</title></head><body bgcolor="white">

<b><xsl:value-of select="name"/></b><br /><xsl:value-of select="affiliation"/><br /><i><xsl:value-of select="email"/></i>

</body></html>

</xsl:template>

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Style Sheet Output

<html>

<head><title>An author</title></head>

<body bgcolor="white">

<b>Grigoris Antoniou</b><br>

University of Bremen<br>

<i>[email protected]</i>

</body>

</html>

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Observations About XSLT

XSLT documents are XML documents XSLT resides on top of XML

The XSLT document defines a template In this case an HTML document, with some

placeholders for content to be inserted xsl:value-of retrieves the value of an

element and copies it into the output document It places some content into the template

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A Template

<html>

<head><title>An author</title></head>

<body bgcolor="white">

<b>...</b><br>

...<br>

<i>...</i>

</body>

</html>

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Auxiliary Templates

We have an XML document with details of several authors

It is a waste of effort to treat each author element separately

In such cases, a special template is defined for author elements, which is used by the main template

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Example of XML Document

<authors><author>

<name>Grigoris Antoniou</name><affiliation>University of Bremen</affiliation><email>[email protected]</email>

</author><author>

<name>David Billington</name><affiliation>Griffith University</affiliation><email>[email protected]</email>

</author></authors>

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Example of an Auxiliary Template

<xsl:template match="/"><html>

<head><title>Authors</title></head><body bgcolor="white">

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

</body></html>

</xsl:template>

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Example of an Auxiliary Template (2)

<xsl:template match="authors"><xsl:apply-templates select="author"/>

</xsl:template><xsl:template match="author">

<h2><xsl:value-of select="name"/></h2>Affiliation:<xsl:value-of

select="affiliation"/><br>Email: <xsl:value-of select="email"/><p>

</xsl:template>

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Multiple Authors Output

<html><head><title>Authors</title></head><body bgcolor="white">

<h2>Grigoris Antoniou</h2>Affiliation: University of Bremen<br>Email: [email protected]<p><h2>David Billington</h2>Affiliation: Griffith University<br>Email: [email protected]<p>

</body></html>

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Explanation of the Example

xsl:apply-templates element causes all children of the context node to be matched against the selected path expression E.g., if the current template applies to /, then the element

xsl:apply-templates applies to the root element I.e. the authors element (/ is located above the root element) If the current context node is the authors element, then the

element xsl:apply-templates select="author" causes the template for the author elements to be applied to all author children of the authors element

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Explanation of the Example (2)

It is good practice to define a template for each element type in the documentEven if no specific processing is applied to

certain elements, the xsl:apply-templates element should be used

E.g. authors In this way, we work from the root to the

leaves of the tree, and all templates are applied

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Processing XML Attributes

Suppose we wish to transform to itself the element:

<person firstname="John" lastname="Woo"/>

Wrong solution:

<xsl:template match="person"><person firstname="<xsl:value-of select="@firstname">"lastname="<xsl:value-of select="@lastname">"/>

</xsl:template>

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Processing XML Attributes (2)

Not well-formed because tags are not allowed within the values of attributes

We wish to add attribute values into template

<xsl:template match="person"><person

firstname="{@firstname}"lastname="{@lastname}"/>

</xsl:template>

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Transforming an XML Document to Another

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Transforming an XML Document to Another (2)

<xsl:template match="/"><?xml version="1.0" encoding="UTF-16"?><authors>

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

</xsl:template>

<xsl:template match="authors"><author>

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

</xsl:template>

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Transforming an XML Document to Another (3)

<xsl:template match="author"><name><xsl:value-of select="name"/></name><contact>

<institution><xsl:value-of select="affiliation"/>

</institution><email><xsl:value-of

select="email"/></email></contact>

</xsl:template>

Creating XSLT document

Example of empty XSLT document

<?xml version=‘1.0’ encoding=‘UTF-8’?><xsl:stylesheet

xmlns:xsl=‘http://www.w3.org/1999/XSL/Transform’ version=‘1.0’></xsl:stylesheet>

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Note: This will simply copy the text content of the input document to the output.

XSLT Features

TemplatesMap input patterns to output

Conditionals Loops Functions Extensions

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Conditionals

If statement<xsl:if test='expression'> ... </xsl:if>

Switch statement<xsl:choose>

<xsl:when test='expression'> ... </xsl:when> <xsl:otherwise> ... </xsl:otherwise>

</xsl:choose> Predicates

foo[@bar="value"]

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Loops

For statement<xsl:for-each select='expression'>

<xsl:sort select='expression'/> …

</xsl:for-each>

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XPath Functions

Node-set functionse.g. position(), last(), local-name(), etc…

String functionse.g. string(), contains(), substring(), etc…

Boolean functionse.g. boolean(), not(), etc…

Number functionse.g. number(), sum(), round(), etc…

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Example Transformation Source

Destination

01 <order>02 <item code=‘BK123’>03 <name>Care and Feeding of Wombats</name>04 <price currency=‘USD’>42.00</price>05 </item>06 </order>

01 <HTML>02 <BODY>03 <TABLE border=‘1’>04 <TR> <TH>Item</TH> <TH>Price</TH> </TR>05 <TR> 06 <TD>BK123 - <U>Care and Feeding of Wombats</U></TD>07 <TD>$42.00</TD>08 </TR>09 </TABLE>10 </BODY>11 </HTML>

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Example Transformation (1 of 14)

Match <order> element01 <xsl:stylesheet xmlns:xsl=‘http://www.w3.org/1999/XSL/Transform’02 version=‘1.0’>0304 <xsl:template match=‘/order’>05 <HTML>06 <BODY>07 <TABLE border=‘1’>08 <TR> <TH>Item</TH> <TH>Price</TH> </TR>09 <xsl:for-each select=‘item’>10 <xsl:apply-templates/>11 </xsl:for-each>12 </TABLE>13 </BODY>14 </HTML>15 </xsl:template>

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Match <item> element

17 <xsl:template match=‘item’>18 <TR>19 <TD>20 <xsl:value-of select=‘@code’/> -21 <U> <xsl:value-of select=‘name’/> </U>22 </TD>23 <xsl:apply-templates select=‘price’/>24 </TR>25 </xsl:template>

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Match <item> element17 <xsl:template match=‘item’>18 <TR>19 <TD>20 <xsl:value-of select=‘@code’/> -21 <U> <xsl:value-of select=‘name’/> </U>22 </TD>23 <xsl:apply-templates select=‘price’/>24 </TR>25 </xsl:template>

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Match <price> element27 <xsl:template match=‘price’>28 <TD>29 <xsl:choose>30 <xsl:when test=‘@currency/text()=“JPN”’> ¥ </xsl:when>31 <xsl:otherwise> $ </xsl:otherwise>32 </xsl:choose>33 <xsl:value-of select=‘text()’/>34 </TD>35 </xsl:template>3637 </xsl:stylesheet>

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Match <price> element27 <xsl:template match=‘price’>28 <TD>29 <xsl:choose>30 <xsl:when test=‘@currency/text()=“JPN”’> ¥ </xsl:when>31 <xsl:otherwise> $ </xsl:otherwise>32 </xsl:choose>33 <xsl:value-of select=‘text()’/>34 </TD>35 </xsl:template>3637 </xsl:stylesheet>

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Match <price> element

27 <xsl:template match=‘price’>28 <TD>29 <xsl:choose>30 <xsl:when test=‘@currency/text()=“JPN”’> ¥ </xsl:when>31 <xsl:otherwise> $ </xsl:otherwise>32 </xsl:choose>33 <xsl:value-of select=‘text()’/>34 </TD>35 </xsl:template>3637 </xsl:stylesheet>

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Match <price> element

27 <xsl:template match=‘price’>28 <TD>29 <xsl:choose>30 <xsl:when test=‘@currency/text()=“JPN”’> ¥ </xsl:when>31 <xsl:otherwise> $ </xsl:otherwise>32 </xsl:choose>33 <xsl:value-of select=‘text()’/>34 </TD>35 </xsl:template>3637 </xsl:stylesheet>

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Output

Item Price

BK123 - Care and Feeding of Wombats $42.00

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Rendering XML in Browsers Latest browsers (e.g. IE 6.0+) have support

for XSLT Insert “xml-stylesheet” processing instruction

<?xml-stylesheet type=‘text/xsl’ href=‘style.xsl’?> Output

Item Price

BK123 - Care and Feeding of Wombats $42.00

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Useful Links

XPath 1.0 Specificationhttp://www.w3.org/TR/xpath

XSLT 1.0 Specificationhttp://www.w3.org/TR/xslt

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XML Data Processing and Transformation ดร. มารุต บูรณรัช...

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