Beginning XML. 4 Ed

Beginning XML, 4th Edition....1

 About the Authors....8

 Credits....9

 Acknowledgments....11

 Contents....13

 Introduction....29

 Part I - Introduction....39

 Chapter 1: What Is XML?....41

 Of Data....-1

 Binary Files....42

 Text Files....43

 A Brief History of Markup....44

 So What Is XML?....45

 What Does XML Buy Us?....48

 HTML and XML: Apples and Red Delicious Apples....51

 Hierarchies of Information....52

 What’s a Document Type?....55

 No....-1

 Origin of the XML Standards....56

 What Is the World Wide Web Consortium?....56

 Components of XML....57

 Where XML Can Be Used....-1

 Reducing Server Load....58

 Website Content....58

 Distributed Computing....59

 e-Commerce....59

 Summary....60

 Exercise Questions....60

 Question 1....60

 Question 2....60

 Chapter 2: Well-Formed XML....61

 Parsing XML....62

 Tags and Text and Elements....-1

 Rules for Elements....69

 Attributes....77

 When to Use Attributes....81

 Comments....83

 Empty Elements....87

 XML Declarations....88

 Version....89

 Encoding....89

 Standalone....91

 Processing Instructions....94

 Illegal PCDATA Characters....97

 Escaping Characters....98

 CDATA Sections....99

 Errors in XML....102

 Summary....102

 Exercise Questions....103

 Question 1....103

 Question 2....103

 Chapter 3: XML Namespaces....105

 Why We Need Namespaces....105

 Using Prefixes....107

 Why Doesn’t XML Just Use These Prefixes?....108

 How XML Namespaces Work....110

 Default Namespaces....113

 Do Different Notations Make Any Difference?....119

 Namespaces and Attributes....121

 Understanding URIs....124

 URLs....124

 URNs....125

 Why Use URLs for Namespaces....-1

 What Do Namespace URIs Really Mean?....126

 RDDL....127

 When to Use Namespaces....127

 Summary....128

 Exercise Questions....129

 Question 1....129

 Question 2....129

 Question 3....129

 Part II - Validation....131

 Chapter 4: Document Type Definitions....133

 Running the Samples....134

 Preparing the Ground....134

 The Document Type Declaration....138

 Sharing Vocabularies....142

 Anatomy of a DTD....143

 Element Declarations....143

 Attribute Declarations....158

 Entities....169

 Developing DTDs....179

 DTD Limitations....180

 DTD Syntax....180

 XML Namespaces....181

 Data Typing....181

 Limited Content Model Descriptions....181

 Summary....181

 Exercise Questions....182

 Question 1....182

 Question 2....182

 Question 3....182

 Chapter 5: XML Schemas....183

 Benefits of XML Schemas....184

 XML Schemas Use XML Syntax....184

 XML Schema Namespace Support....184

 XML Schema Data Types....185

 XML Schema Content Models....185

 Do We Still Need DTDs?....185

 XML Schemas....186

 The XML Schema Document....186

 Running the Samples....186

 Declarations....190

 Declarations....193

 Declarations....203

 Declarations....205

 Content Models....206

 Declarations....215

 Declarations....221

 Creating Elements with Simple Content and Attributes....223

 Datatypes....224

 Declarations....231

 Creating a Schema from Multiple Documents....238

 Declarations....238

 Declarations....242

 Documenting XML Schemas....244

 Comments....244

 Attributes from Other Namespaces....245

 Annotations....246

 Summary....247

 Exercise Questions....248

 Question 1....248

 Question 2....248

 Question 3....248

 Chapter 6: RELAX NG....249

 XML and Compact Syntaxes....250

 Running the Samples....250

 RELAX NG Patterns....251

 Element....-1

 Combining and Reusing Patterns and Grammars....265

 Named Patterns....265

 Combining Named Pattern Definitions....268

 Schema Modularization Using the include Directive....269

 Redefining Included Named Patterns....270

 Removing Patterns with the notAllowed Pattern....271

 Extensions and Restrictions....272

 Nested Grammars....273

 Additional RELAX NG Features....274

 Namespaces....274

 Name-Classes....275

 Datatypes....279

 List Patterns....281

 Comments and Divisions....282

 Useful Resources....283

 Summary....283

 Exercise Questions....283

 Question 1....284

 Question 2....284

 Part III - Processing....285

 Chapter 7: XPath....287

 Ways of Looking at an XML Document....288

 Modeling XML Documents....288

 Visualizing XPath....289

 Understanding Context....290

 What Is a Node?....292

 XPath 1.0 Types....295

 Abbreviated and Unabbreviated Syntax....297

 XPath 1.0 Axes....298

 Child Axis....298

 attribute Axis....300

 ancestor Axis....302

 ancestor-or-self Axis....303

 descendant Axis....303

 descendant-or-self Axis....304

 following Axis....304

 following-sibling Axis....306

 namespace Axis....306

 parent Axis....309

 preceding Axis....309

 preceding-sibling Axis....310

 self Axis....311

 XPath 1.0 Functions....312

 Boolean Functions....312

 Node-Set Functions....313

 Numeric Functions....313

 String Functions....314

 Predicates....316

 Structure of XPath Expressions....316

 XPath 2.0....319

 Revised XPath Data Model....319

 W3C XML Schema Data Types....319

 Additional XPath 2.0 Functions....320

 XPath 2.0 Features....320

 Summary....323

 Exercise Questions....323

 Question 1....324

 Question 2....324

 Chapter 8: XSLT....325

 What Is XSLT?....325

 Restructuring XML....326

 Presenting XML Content....326

 How an XSLT Processor Works....326

 Running the Examples....327

 Introducing the Saxon XSLT Processor....327

 Installing the Saxon XSLT Processor....328

 Procedural versus Declarative Programming....330

 Procedural Programming....330

 Declarative Programming....330

 Foundational XSLT Elements....331

 The Element....333

 The Element....334

 The Element....334

 Getting Information from the Source Tree....335

 The Element....335

 The Element....337

 The Element....341

 Influencing the Output with the Element....344

 Conditional Processing....344

 The Element....344

 The Element....346

 The Element....349

 The Element....350

 XSLT Modes....352

 XSLT Variables and Parameters....358

 Named Templates and the Element....360

 XSLT Functions....361

 XSLT 2.0....361

 Grouping in Version 2.0....362

 Non-XML Input and String Handling....365

 Multiple Outputs....368

 User-Defined Functions....370

 xsl:value-of changes....372

 Summary....373

 Exercise Questions....373

 Question 1....373

 Question 2....373

 Part IV - Databases....375

 Chapter 9: XQuery, the XML Quey Language....377

 Why XQuery?....378

 Historical Factors....378

 Technical Factors....378

 Current Status....379

 XQuery Tools....381

 Saxon....381

 X-Hive.com Online....383

 X-Hive Database....384

 Tamino Database....384

 Microsoft SQL Server 2005....384

 Oracle....384

 Some XQuery Examples....384

 Input Functions....384

 Retrieving Nodes....386

 Element Constructors....389

 The XQuery Prolog....393

 Computed Constructors....396

 Syntax....397

 The XQuery Data Model....398

 Shared Data Model with XPath 2.0 and XSLT 2.0....398

 Node Kinds....399

 Sequences of Node-Sets....399

 Document Order....399

 Comparing Items and Nodes....399

 Types in XQuery....399

 Axes in XQuery....399

 XQuery Expressions....400

 FLWOR Expressions....400

 XQuery Functions....406

 The concat() Function....407

 The count() Function....407

 Using Parameters with XQuery....408

 User-Defined Functions....409

 Looking Ahead....410

 Update Functionality....410

 Full-Text Search....410

 Summary....410

 Exercise Questions....411

 Question 1....411

 Question 2....411

 Chapter 10: XML and Databases....413

 The Need for Efficient XML Data Stores....413

 The Increasing Amount of XML....414

 Comparing XML-Based Data and Relational Data....415

 Approaches to Storing XML....416

 Storing XML on File Systems....416

 Using XML With Conventional Databases....417

 Native XML Databases....419

 Using Native XML Databases....420

 Obtaining and Installing eXist....420

 Interacting with eXist....422

 XML in Commercial RDBMSs....433

 XML Functionality in SQL Server 2000....433

 Web Service Support....464

 XML in Open Source RDBMS....464

 Installing MySQL....464

 Adding Information in MySQL....465

 Querying MySQL....468

 Updating XML in MySQL....473

 Usability of XML in MySQL....474

 Client-Side XML Support....475

 Choosing a Database to Store XML....476

 Looking Ahead....476

 Summary....476

 Exercise Questions....476

 Question 1....477

 Question 2....477

 Question 3....477

 Part V - Programming....479

 Chapter 11: The XML Document Object Model (DOM)....481

 Purpose of the XML DOM....481

 Interfaces and Objects....483

 The Document Object Model at the W3C....484

 XML DOM Implementations....485

 Two Ways to View DOM Nodes....486

 Overview of the XML DOM....486

 Tools to Run the Examples....488

 Browser Differences....488

 The Node Object....496

 Properties of the Node Object....496

 Methods of the Node Object....499

 Loading an XML Document....500

 The Effect of Text Nodes....506

 The NamedNodeMap Object....509

 The NodeList Object....513

 The DOMException Object....514

 The Document Interface....516

 How the XML DOM Is Used in InfoPath 2007....519

 Summary....520

 Exercise Questions....520

 Question 1....520

 Question 2....520

 Chapter 12: Simple API for XML (SAX)....521

 What Is SAX and Why Was It Invented?....521

 A Brief History of SAX....522

 Where to Get SAX....523

 Setting Up SAX....524

 Receiving SAX Events....524

 ContentHandler Interface....525

 ErrorHandler Interface....542

 DTDHandler Interface....547

 EntityResolver Interface....548

 Features and Properties....548

 Extension Interfaces....552

 Good SAX and Bad SAX....553

 Consumers....-1

 Other Languages....554

 Summary....555

 Exercise Questions....556

 Question 1....556

 Question 2....556

 Part VI - Communication....557

 Chapter 13: RSS Atom, and Content Syndication....559

 Syndication and Meta Data....559

 Syndication Systems....560

 The Origin of RSS Species....563

 RSS-DEV and RSS 1.0....567

 UserLand and RSS 2.0....569

 Atom....571

 Working with News Feeds....574

 Newsreaders....574

 Data Quality....574

 A Simple Aggregator....575

 Modeling Feeds....575

 Program Flow....578

 Implementation....578

 Transforming RSS with XSLT....595

 Useful Resources....605

 Summary....606

 Exercise Questions....606

 Question 1....607

 Question 2....607

 Chapter 14: Web Services....609

 What Is an RPC?....609

 RPC Protocols....611

 DCOM....611

 IIOP....612

 Java RMI....613

 The New RPC Protocol: Web Services....613

 XML-RPC....614

 The Network Transport....617

 Taking a REST....634

 The Web Services Stack....638

 SOAP....638

 WSDL....639

 UDDI....640

 Surrounding Specifications....640

 Summary....642

 Exercise Questions....643

 Question 1....643

 Question 2....643

 Chapter 15: SOAP and WSDL....645

 Laying the Groundwork....646

 Running Examples in Windows 2003....-1

 The New RPC Protocol: SOAP....646

 Just RESTing....650

 Basic SOAP Messages....651

 More Complex SOAP Interactions....658

 Defining Web Services: WSDL....670

 ....671

 ....671

 ....672

 ....673

 ....673

 ....675

 ....676

 Other Bindings....679

 Summary....682

 Exercise Questions....682

 Question 1....682

 Question 2....682

 Chapter 16: Ajax....683

 Early Attempts at Asynchronous Updates....683

 Microsoft versus Mozilla....685

 Cross-Browser Solutions....685

 Basic Posting Techniques....687

 Transport and Processing on the Server....690

 JSON....690

 Payment Card Validator....691

 The AutoSuggest Box....696

 Server-Side Proxies....719

 The Currency Converter Proxy....720

 Summary....724

 Exercise Questions....725

 Question 1....725

 Question 2....725

 Question 3....725

 Part VII - Display....727

 Chapter 17: Cascading Style Sheets (CSS)....729

 Why Stylesheets?....730

 Introducing CSS....731

 CSS Properties....732

 Inheritance....733

 Attaching the Stylesheet to an XML Document....737

 Selectors....738

 Using CSS for Layout of XML Documents....739

 Understanding the Box Model....740

 Positioning in CSS....744

 Laying Out Tabular Data....757

 Links in XML Documents....759

 XLink Support in Firefox....759

 Forcing Links Using the XHTML Namespace....763

 Images in XML Documents....763

 Using CSS to Add Content to Documents....764

 Attribute Content....767

 Attribute Selectors....767

 Using Attribute Values in Documents....767

 Summary....770

 Exercise Questions....770

 Question 1....770

 Question 2....771

 Question 3....771

 Question 4....771

 Chapter 18: XHTML....773

 Separating Style from Content....774

 Learning XHTML 1.x....776

 Document Type Definitions for XHTML....776

 Basic Changes in Writing XHTML....778

 Styling XHTML Documents....789

 Stricter Documents Make Faster and Lighter Processors....791

 XHTML Tools....791

 Validating XHTML Documents....792

 Validation Pitfalls....794

 Mime Types Pitfalls....795

 Modularized XHTML....797

 Module Implementations....799

 XHTML 1.1....799

 XHTML Basic....800

 What’s Next for XHTML....801

 Summary....803

 Exercise Questions....804

 Question 1....804

 Question 2....804

 Chapter 19: Scalable Vector Graphics (SVG)....805

 What Is SVG?....805

 Scalable....-1

 Putting SVG to Work....807

 An SVG Toolkit....807

 Getting Started....809

 Views and Units....812

 The Painter’s Model....812

 Grouping....814

 Transformations....814

 Paths....815

 Images....818

 Text....819

 Comments....-1

 Scripting....822

 SVG on Your Website....823

 Tangram: A Simple Application....824

 XHTML Wrapper....825

 SVG Shapes....826

 Tangram Script....830

 Useful Resources....837

 Summary....838

 Exercise Questions....838

 Question 1....838

 Question 2....839

 Chapter 20: XForms....841

 How XForms Improves on HTML Forms....842

 XForms Tools....842

 An Illustrative XForms Example....848

 XForms Form Controls....855

 The xforms:input Element....855

 The xforms:secret Element....856

 The xforms:textarea Element....856

 The xforms:output Element....856

 The xforms:upload Element....857

 The xforms:range Element....857

 The xforms:trigger Element....858

 The xforms:submit Element....858

 The xforms:select Element....859

 The xforms:select1 Element....860

 Constraining XForms Instances....866

 The xforms:bind Element....866

 W3C XML Schema in XForms....871

 Schema or Bind Elements: Which One to Choose?....872

 XForms Events....872

 The XForms Action Module....873

 Developing and Debugging XForms....874

 Alternatives to XForms....874

 Microsoft InfoPath....874

 Adobe LiveCycle....875

 HTML Forms....876

 Summary....876

 Exercise Questions....876

 Question 1....876

 Question 2....876

 Part VIII - Case Study....877

 Chapter 21: Case Study: Payment Calculator....879

 Mortgage Calculations....879

 What You’ll Need....880

 Online Loan Calculator....880

 Integrating the Calculation Web Service....887

 Enhancing the Display with SVG....903

 Adding the Frame to the Main Page....906

 Summary....910

 Chapter 22: Case Study: Payment Calculator — Ruby on Rails....911

 Mortgage Calculations....911

 What You Need for the Example....912

 Creating the Project....913

 Building the Online Loan Calculator....914

 Summary....944

 Appendix A: Exercise Solutions....946

 Chapter 1....946

 Question 1....946

 Question 2....947

 Chapter 2....948

 Question 1....948

 Question 2....951

 Chapter 3....955

 Question 1....955

 Question 2....955

 Question 3....956

 Chapter 4....957

 Question 1....957

 Question 2....957

 Question 3....958

 Chapter 5....958

 Question 1....959

 Question 2....959

 Question 3....960

 Chapter 6....961

 Question 1....961

 Question 2....963

 Chapter 7....963

 Question 1....963

 Question 2....964

 Chapter 8....964

 Question 1....964

 Question 2....964

 Chapter 9....964

 Question 1....965

 Question 2....965

 Chapter 10....965

 Question 1....965

 Question 2....965

 Question 3....966

 Chapter 11....966

 Question 1....966

 Question 2....967

 Chapter 12....967

 Question 1....967

 Question 2....970

 Chapter 13....972

 Question 1....972

 Question 2....974

 Chapter 14....977

 Question 1....977

 Question 2....978

 Chapter 15....979

 Question 1....979

 Question 2....979

 Chapter 16....981

 Question 1....981

 Question 2....982

 Question 3....982

 Chapter 17....982

 Question 1....982

 Question 2....983

 Question 3....984

 Question 4....984

 Chapter 18....984

 Question 1....984

 Question 2....987

 Chapter 19....988

 Question 1....988

 Question 2....991

 Chapter 20....994

 Question 1....994

 Question 2....994

 Appendix B: XPath Reference....996

 XPath 2.0 Is Emerging Slowly....997

 The New Sequencing....997

 Datatyping Control....997

 Axes....997

 Node Tests....1000

 Functions....1002

 XPath 2.0 Functions....1009

 Appendix C: XSLT Reference....1012

 Elements....1013

 Functions....1036

 Available XPath Functions....1039

 Types....1039

 New in XSLT 2.0....1040

 More Powerful Expressions....1040

 Muenchian’s Everywhere....1041

 Planning on Using XSLT 2.0....1041

 New Functions....1042

 A Quick Note on XSLT 2.0 and XQuery 1.0....1042

 Appendix D: The XML Document Obect Model....1044

 Notation....1045

 Basic Datatypes....1048

 Strings....1049

 User Data....1049

 Objects....1049

 Fundamental Interfaces: Core Module....1049

 DOMException....1049

 DOMError....1051

 DOMErrorHandler....1051

 Node....1052

 Document....1056

 DOMImplementation....1058

 DOMImplementationSource....1058

 DOMImplementationList....1059

 DocumentFragment....1060

 NodeList....1060

 DOMStringList....1060

 NameList....1061

 Element....1061

 NamedNodeMap....1063

 Attr....1064

 CharacterData....1064

 Text....1065

 Comment....1065

 TypeInfo....1066

 UserDataHandler....1066

 DOMLocator....1067

 DOMConfiguration....1067

 Extended Interfaces: XML Module....1068

 CDATASection....1068

 ProcessingInstruction....1068

 DocumentType....1068

 Notation....1069

 Entity....1069

 EntityReference....1070

 Load and Save Interfaces....1070

 Data Types....1070

 LSException....1070

 DOMImplementationLS....1071

 LSParser....1071

 LSSerializer....1073

 LSInput....1073

 LSOutput....1074

 LSResourceResolver....1074

 LSParserFilter....1074

 LSSerializerFilter....1075

 LSProgressEvent....1075

 LSLoadEvent....1076

 Validation Interfaces....1076

 ExceptionVAL....1076

 NodeEditVAL....1077

 DocumentEditVAL....1078

 ElementEditVAL....1078

 CharacterDataEditVAL....1080

 Appendix E: XML Schema Element and Attribute Reference....1082

 Unknown....-1

 all....1082

 annotation....1083

 any....1084

 anyAttribute....1085

 appinfo....1086

 attribute....1086

 attributeGroup....1088

 choice....1088

 complexContent....1089

 complexType....1090

 documentation....1091

 element....1092

 extension....1094

 field....1095

 group....1095

 import....1096

 include....1097

 key....1098

 keyref....1100

 list....1100

 notation....1101

 redefine....1101

 restriction....1102

 schema....1104

 selector....1106

 sequence....1106

 simpleContent....1107

 simpleType....1107

 union....1108

 unique....1109

 XML Schema Instance Attributes....1109

 Appendix F: XML Schema Datatypes Reference....1112

 XML Schema Built-in Datatypes....1113

 Constraining Facets....1121

 length....1122

 minLength....1122

 maxLength....1123

 pattern....1124

 enumeration....1124

 whiteSpace....1125

 maxInclusive....1125

 minInclusive....1126

 maxExclusive....1127

 minExclusive....1128

 totalDigits....1128

 fractionDigits....1129

 Appendix G: SAX 2.0.2 Reference....1134

 Classes and Interfaces....1135

 Interface org.xml.sax.Attributes....1136

 Interface org.xml.sax.ext.Attributes2....1140

 Interface org.xml.sax.ContentHandler....1142

 Interface org.xml.sax.ext.DeclHandler....1150

 Interface org.xml.sax.DTDHandler....1152

 Interface org.xml.sax.EntityResolver....1154

 Interface org.xml.sax.ext.EntityResolver2....1156

 Interface org.xml.sax.ErrorHandler....1159

 Class org.xml.sax.InputSource....1161

 Interface org.xml.sax.ext.LexicalHandler....1165

 Interface org.xml.sax.Locator....1168

 Interface org.xml.sax.ext.Locator2....1170

 Exception org.xml.sax.SAXException....1171

 Exception org.xml.sax.SAXNotRecognizedException....1173

 Exception org.xml.sax.SAXNotSupportedException....1173

 Exception org.xml.sax.SAXParseException....1174

 Interface org.xml.sax.XMLFilter....1176

 Interface org.xml.sax.XMLReader....1177

 Index....1186

When the first edition of this book was written, XML was a relatively new language but already gaining ground fast and becoming more and more widely used in a vast range of applications. By the time of the second edition, XML had already proven itself to be more than a passing fad, and was in fact being used throughout the industry for an incredibly wide range of uses. With the third edition, it was clear that XML was a mature technology, but more important, it became evident that the XML landscape was dividing into several areas of expertise. Now in this edition, we needed to categorize the increasing number of specifications surrounding XML, which either use XML or provide functionality in addition to the XML core specification.

So what is XML? It's a markup language, used to describe the structure of data in meaningful ways. Anywhere that data is input/output, stored, or transmitted from one place to another, is a potential fit for XML's capabilities. Perhaps the most well-known applications are web-related (especially with the latest developments in handheld web access—for which some of the technology is XML-based). However, there are many other non-web-based applications for which XML is useful—for example, as a replacement for (or to complement) traditional databases, or for the transfer of financial information between businesses. News organizations, along with individuals, have also been using XML to distribute syndicated news stories and blog entries.

This book aims to teach you all you need to know about XML—what it is, how it works, what technologies surround it, and how it can best be used in a variety of situations, from simple data transfer to using XML in your web pages. It answers the fundamental questions:

What can you use it for, anyway?

This book is for people who know that it would be a pretty good idea to learn XML but aren't 100 percent sure why. You've heard the hype but haven't seen enough substance to figure out what XML is and what it can do. You may be using development tools that try to hide the XML behind user interfaces and scripts, but you want to know what is really happening behind the scenes. You may already be somehow involved in web development and probably even know the basics of HTML, although neither of these qualifications is absolutely necessary for this book.

What you don't need is knowledge of markup languages in general. This book assumes that you're new to the concept of markup languages, and we have structured it in a way that should make sense to the beginner and yet quickly bring you to XML expert status.

 The word "Beginning" in the title refers to the style of the book, rather than the reader's experience level. There are two types of beginner for whom this book is ideal:

The subjects covered in this book are arranged to take you from novice to expert in as logical a manner as we could. This Fourth Edition is structured in sections based on various areas of XML expertise. Unless you are already using XML, you should start by reading the introduction to XML in Part I. From there, you can quickly jump into specific areas of expertise, or, if you prefer, you can read through the book in order. Keep in mind that there is quite a lot of overlap in XML, and that some of the sections make use of techniques described elsewhere in the book.

This book builds on the strengths of the earlier editions, and provides new material to reflect the changes in the XML landscape—notably XQuery, RSS and Atom, and AJAX. Updates have been made to reflect the most recent versions of specifications and best practices throughout the book. In addition to the many changes, each chapter has a set of exercise questions to test your understanding of the material. Possible solutions to these questions appear in Appendix A.