Presenting XML Using Stylesheets

A key advantage of using XML as a datasource is that its presentation (such as a web page) can be separate from its structure and content.

• Presentation. Applied stylesheets define its presentation. XML data can be presented in various ways, both in appearance and organization, simply by applying different stylesheets.

• Structure and content: XML data defines the structure and content.

Stylesheet Uses

Consider these ways of using stylesheets:

• A different interface can be presented to different users based on user profile, browser type, or other criteria by defining a different stylesheet for each presentation style.

• Stylesheets can be used to transform XML data into a format tailored to the specific application that receives and processes the data.

Stylesheets can be applied on the server or client side. The XSL-Transformation Processor (XSL-T Processor) transforms one XML format into XML or any other text-based format such as HTML. Oracle XML Parsers all include an XSL-T Processor.

How to apply stylesheets and use the XSL-T Processor is described in the following sections:

• Chapter 17, "Using XML Parser for Java"

• Chapter 11, "Customizing Discoverer 3i Viewer with XSL"

eXtensible Stylesheet Language (XSL)

eXtensible Stylesheet Language (XSL), the stylesheet language of XML is another W3C recommendation. XSL provides for stylesheets that allow you to do the following:

• Transform XML into XML or other text-based formats such as HTML

• Rearrange or filter data

• Convert XML data to XML that conforms with another Document Type Definition (DTD), an important capability for allowing different applications to share data

Cascading Style Sheets (CSS)

Cascading Style Sheets (CSS1), a W3C specification was originally created for use with HTML documents. With CSS you can control the following aspects of your document's appearance:

• Spacing. Element visbility, position, and size

• Colors and background

• Fonts and text

CSS2 was published by W3C in 1998 and includes the following additional features:

• System fonts and colors

• Automatic numbering

• Supports paged media

• Tables and aura stylesheets

'Cascading' here implies that you can apply several stylesheets to any one document. On a web page deploying CSSm, for example, three stylesheets can apply or cascade:

1. User's preferred stylesheet takes precedence

2. Cascading stylesheet

3. Browser stylesheet