10.4 Oracle Application Server Components and XML

Several of the Oracle Application Server components use XML in various ways. Their use of XML ranges from simply using XML documents (to save configuration data) to creating XML documents as output. The most notable use of XML by Oracle Application Server components is found in OracleAS Portal and OracleAS Report Services. These two Oracle Application Server components can use XML as a data source, and produce XML documents for output. This capability makes it possible to use the XML SQL Utility or XSQL Pages to produce input for OracleAS Portal and OracleAS Reports Services or use output from OracleAS Portal and OracleAS Reports Services to update a database with XML SQL Utility or XSQL Pages, or both.

The OracleAS Wireless component, covered separately in Chapter 14, uses XSLT transformation bidirectionally to enable alternative presentation layers for web-based applications to wireless devices such as handheld computers and cell phones. Web Services, the topic of Chapter 11, employ XML to provide a computer-centric, rather than human-centric, view of the Web. Web Services enable heterogeneous computer systems to exchange data over an intranet or the Internet.

OracleAS Portal's Portal Developer Kit Integration Services (PDKIS) allows you to extract data from an external source identified by a URL. If the URL points to a well- formed HTML document, the HTML document can be parsed and used for content in a portlet. PDKIS can also transform an HTML document into an XHTML document. (As mentioned earlier, XHTML is an XML version of HTML.) The XHTML document can then be further transformed using an XSL stylesheet to create content for a portlet.

OracleAS Reports Services can use an XML document as a data source for a report. It can also output reports as XML documents and perform XSL transformations on report output.