This section provides a brief introduction of the XSL-FO (XSL Formatting Objects) technology.
XSL-FO: An XML based markup language that defines how the embedded information
should be formatted for viewing or printing. XSL-FO is very similar to TeX, which was
a very popular language 15 years ago for writing well formatted scientific documents.
Main features of XSL-FO:
1. XSL-FO is XML based. So an XSL-FO document is also an XML document.
2. XSL-FO documents requires to an XSL-FO processor to comile them into new output formats that are suitable for viewing or printing.
Common XSL-FO output formats are text, PDF and PS files.
3. XSL-FO can be embedded inside XSL transformation stylesheet files.
In this case, the content source XML file will be processed in 2 steps in order to get the viewing or printing output files:
The content source XML file will be transformed according to the stylesheet file - the resulting file, XSL-FO file,
will contain the transformed content with XSL-FO statements.
The XSL-FO file will be compiled by XSL-FO processors into viewing or printing output files.
The 2-step process can be viewed as in this diagram:
Content source (XML format)
| XSLT stylesheet with XSL-FO statements
|<- XSLT transforming
Content with XSL-FO statements (XML format)
|<- XSL-FO processing
Printing document (PDF format)