<REPORT NAME> XML USAGE ASSESSMENT REPORT VERSION: 1.0 <FILENAME REFERENCE> XMLUSE.DOC Issue Date: 30-06-2000 Version Number: 1.0 XML ASSESSMENT USAGE REPORT Written by: Dimitrios Oikonomidis & Michael Papaioannou, Students of Department of Informatics at Athens University of Economics and Business Issue Date: 30-06-2000 File Ref :xmluse.doc Page: 1/130 <REPORT NAME> XML USAGE ASSESSMENT REPORT VERSION: 1.0 <FILENAME REFERENCE> XMLUSE.DOC Table of Contents 1. INTRODUCTION...........................................................................................................7 2. XML...............................................................................................................................9 2.1 Introduction in XML........................................................................................................................... 9 2.2 Design goals for XML ......................................................................................................................... 9 2.3 Syntax of XML................................................................................................................................... 10 2.4 DTDs in XML .................................................................................................................................... 12 2.4.1 Introduction in DTDs...................................................................................................................... 12 2.4.2 Syntax of DTDs in XML ................................................................................................................ 12 2.4.3 Validity ........................................................................................................................................... 15 2.4.4 Namespaces..................................................................................................................................... 16 2.4.5 Schemas .......................................................................................................................................... 16 2.4.6 Data types........................................................................................................................................ 17 2.5 XML APIs .......................................................................................................................................... 17 2.5.1 Tree-based APIs - DOM ................................................................................................................. 17 2.5.2 Event-based APIs - SAX................................................................................................................. 19 2.6 Navigation with XML ....................................................................................................................... 20 2.6.1 Introduction in Links....................................................................................................................... 20 2.6.2 Types of XML links........................................................................................................................ 21 2.7 Usage of XML .................................................................................................................................... 22 2.7.1 Applications .................................................................................................................................... 22 2.7.2 Browsers.......................................................................................................................................... 23 2.7.3 XML Parsers ................................................................................................................................... 24 2.7.4 XML Agents ................................................................................................................................... 26 2.7.5 Metadata Formats............................................................................................................................ 26 2.8 Future ................................................................................................................................................. 28 2.8.1 XML and e-business ....................................................................................................................... 29 2.8.2 XML - EDI...................................................................................................................................... 30 3. XSL .............................................................................................................................32 3.1 Introduction in XSL .......................................................................................................................... 32 3.2 Design Principles ............................................................................................................................... 33 Issue Date: 30-06-2000 File Ref :xmluse.doc Page: 2/130 <REPORT NAME> XML USAGE ASSESSMENT REPORT VERSION: 1.0 <FILENAME REFERENCE> XMLUSE.DOC 3.3 Current Options For Displaying XML Documents........................................................................ 33 3.4 Why Use Style sheet .......................................................................................................................... 34 3.5 A Simple Description Of How XSL Works..................................................................................... 34 3.6 An Analytical Approach Of XSL Operation................................................................................... 35 3.6.1 Tree Transformation ....................................................................................................................... 36 3.6.2 Formatting....................................................................................................................................... 37 3.6.3 Construction Of Area Tree.............................................................................................................. 39 3.7 Parts Of XSL...................................................................................................................................... 40 3.8 Formatting Model – The Output of XSL Operation...................................................................... 41 3.9 Structure Of XSL (Using Examples) ............................................................................................... 41 3.9.1 Templates........................................................................................................................................ 42 3.9.2 Conditional Processing ................................................................................................................... 45 3.9.3 Variables ......................................................................................................................................... 45 3.9.4 Creating the Result Tree ................................................................................................................. 46 3.9.5 Overall XSL formatting capabilities ............................................................................................... 46 3.9.6 Formatting objects and properties................................................................................................... 47 3.9.7 Formatting Object Basics................................................................................................................ 47 3.9.8 Basic properties............................................................................................................................... 47 3.10 Benefits of XSL .................................................................................................................................. 48 3.11 XSL-Enabled Tools ........................................................................................................................... 50 3.11.1 XSLT Processors............................................................................................................................. 50 3.11.2 XSL-FO processors......................................................................................................................... 51 3.11.3 XSL-Enabled Authoring Tools ....................................................................................................... 52 3.12 The Future Of XSL ........................................................................................................................... 54 4. XQL Language ...........................................................................................................55 4.1 Why Use A Query Language?.......................................................................................................... 55 4.2 Purposes Of Creating XQL .............................................................................................................. 55 4.3 SQL vs. XQL...................................................................................................................................... 56 4.4 Where Can XQL Queries Be Used?................................................................................................. 57 4.5 General Requirements Of XQL ....................................................................................................... 58 4.5.1 XML Query Data Model................................................................................................................. 58 4.5.2 XML Query Functionality .............................................................................................................