Introduction to XSL (=eXtensible Stylesheet Language)
XSL - The Style Sheet of XML?!?
 | HTML pages uses predefined tags, and the meaning of these tags is well understood: <p> means a paragraph and <h1> means a header, and the browser knows how to display these pages. |
| With XML we can use any tags we want, and the meaning of these tags are not automatically understood by the browser: <table> could mean a HTML table or maybe a piece of furniture. |
| Because of the nature of XML, there is no standard way to display an XML document. |
| In order to display XML documents, it is necessary to have a mechanism to describe how the document should be displayed. |
| One of these mechanisms is Cascading Style Sheets (CSS), |
| but XSL (eXtensible Stylesheet Language) is the preferred style sheet language of XML, |
| and XSL is far more sophisticated than the CSS used by HTML. |
XSL - More than a Style Sheet
| XSL consists of two parts:
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| XSL is a language that can transform XML into HTML, | ||||
| A language that can filter and sort XML data and a language that can format XML data, based on the data value, like displaying negative numbers in red. |
XSL - What can it do?
| XSL can be used to define how an XML file should be displayed by transforming the XML file into a format that is recognizable to a browser--one such format is HTML. |
| Normally XSL does this by transforming each XML element into an HTML element. |
| XSL can also add completely new elements into the output file, or to remove elements. |
| It can rearrange and sort the elements, and test and make decisions about witch elements to display, and a lot more. |
The attached pages provide examples and further details.