XML in a Nutshell, 3rd Edition

Mixing Your Own XHTML

The XHTML 1.1 DTD does not include all of the modules that are available. For instance, frames and the legacy presentational elements are deliberately omitted and cannot easily be turned on. This is the W3C’s not-so-subtle way of telling you that you shouldn’t be using these elements in the first place. If you do want to use them, you’ll need to create your own complete DTD using the individual modules you require.

To do this, you must first define the namespace URI and prefixed names for your elements and attributes. The W3C provides a template you can adapt for this purpose at http://www.w3.org/TR/xhtml-modularization/DTD/templates/template-qname-1.mod. Example 7-6 demonstrates with a DTD fragment that defines the names for the today and quoteoftheday elements that one of the authors (Harold) uses on his web sites. The module is based on the W3C-provided template.

Example 7-6. A DTD module to define the today and quoteoftheday elements’ names and namespaces

<!-- ........................................................... --> <!-- CafeML Qualified Names Module ............................. --> <!-- file: cafe-qname-1.mod This is an extension of XHTML, a reformulation of HTML as a modular XML application. This DTD module is identified by the PUBLIC and SYSTEM identifiers: PUBLIC "-//Elliotte Rusty Harold//ELEMENTS CafeML Qualified Names 1.0//EN" "cafe-qname-1.mod" ........................................................... --> <!-- NOTES: Using the CafeML Qualified ...