• Chapter 1: Getting Started with Stylus Studio
• Chapter 2: Editing and Querying XML
• Chapter 3: Converting Non-XML Files to XML
• Chapter 4: Working with XSLT
• Chapter 5: Creating XSLT Using the XSLT Mapper
• Chapter 6: Debugging Stylesheets
• Chapter 7: Defining XML Schemas
• Chapter 8: Defining Document Type Definitions
  • What Is a DTD?
  • Creating DTDs
  • About Editing DTDs
  • About Modifiers in Element Definitions in DTDs
  • Defining Elements in DTDs
  • Defining General Entities and Parameter Entities in DTDs
  • Inserting White Space in DTDs
  • Adding Comments to DTDs
  • About Node Properties in DTDs
  • Associating an XML Document with an External DTD
  • Moving an Internal DTD to an External File
• Chapter 9: Writing XPath Expressions
• Chapter 10: Working with XQuery in Stylus Studio
• Chapter 11: Composing Web Service Calls
• Chapter 12: Accessing Relational Data as XML
• Chapter 13: Extending Stylus Studio
• Chapter 14: Stylus Studio Reference

Home > Online Product Documentation > Table of Contents > Simple Example of Aggregating Modifiers in DTDs

Simple Example of Aggregating Modifiers in DTDs

Suppose you want a book element to always contain exactly one title element and any number of author elements. The title and author elements contain only raw data. To accomplish this, you would perform steps that generate the following tree representation:

book
               

              

                
Sequence
                   
title
                   
One or More
                   

                
              
author
               
title
               

              

                
Zero or More
                   
#PCDATA
                   

                
              
author
               

              

                
Zero or More
                   
#PCDATA
                   

                
              

            

In the book element definition, Sequence modifies book and One or More modifies Sequence. Because the title element immediately follows the Sequence modifier, the default occurrence rule is assumed. That is, the title element must appear exactly once. In the Text view of the DTD, the definition for the book element is as follows:

<!ELEMENT book (title, (author)+)>