Why XHTML Modularization?

The XHTML modularization model defines the modules of XHTML.
XHTML is a simple, but large language. XHTML contains most of the functionality a web developer will need.

For some purposes XHTML is too large and complex, and for other purposes it is much too simple.

By splitting XHTML into modules, the W3C (World Wide web Consortium) has created small and well-defined sets of XHTML elements that can be used separately for simple devices as well as combined with other XML standards into larger and more complex applications.

With modular XHTML, product and application designers can:
* Choose the elements to be supported by a device using standard XHTML building blocks.
* Add extensions to XHTML, using XML, without breaking the XHTML standard.
* Simplify XHTML for devices like hand held computers, mobile phones, TV, and home appliances.
* Extend XHTML for complex applications by adding new XML functionality (like MathML, SVG, Voice and Multimedia).
* Define XHTML profiles like XHTML Basic (a subset of XHTML for mobile devices).

 

What about elements that don't have a close tag, such as <IMG> and <hr> ?

There are two solutions. You could use a close tag (e.g. <img src="logo.gif" ...></img>). However the best solution is to simply include a forward slash in the element: <img src="logo.gif" ... />
Will this work?
As long as you include a space before the slash it will cause no problems in most Web browsers - although there have been reports of problems with some embedded HTML viewers such as Java's Swing HTML editor.

 

Why do we need modular DTDs?

An application may wish to support only a subset of XHTML. For example a mobile phone, an Internet TV or even a Web-aware cooker may only require a subset of XHTML. Also modularity makes it easier to deploy new developments.

 

Any other important new developments?

Yes: XSLT provides a transformation language which can be used to transform XML documents into other formats. XSLT can be used to transform documents from one XML DTD to another, or even to transform an XML document to an alternative format such as RTF or PDF.

 

Why is this XSLT important?

You've heard all the hype about mobile phones and WAP haven't you? How do you think the WAP world, which expects documents to be in WML format, to be populated? Rather than manually creating WML markup, XSLT will enable XHTML documents to be automatically converted to WML.