This is an XML document that describes pipes and filters for the application.

The top level element

The descriptor stats with a xpipeDef element under the namespace of "http://www.xml.org/xml/pipe"

The element contains zero or more register elements.

The register element

The register element registers a filter or a pipe with the server:

Register an XSLT filter

Each register must have a uri attribute, which is combined with the application uri to generate the resource uri. In the example given above, the resource uri becomes: http://www.xmlpipe.org/xpe/manual/xslt/xml2html/xmlRender, if the baseURI of the application defined in the xar.xml is "http://www.xmlpipe.org/xpe/manual" .

The xslt element has a href attribute, which points to an XSLT script. The location of the the script is a URI relative to the URI of the application. Because the URI standard is used, so we always uses the "/" seperator even on a Windows platform.

Register an XML Pipe

To register an xpipe, we just embed a pipe within the register element:

An XPipe is defined by an xpipe element, which consists of a number of xnode elements and one xink element.

An xnode or xsink element has a type attribute, which points to a resource. If relative URI is used, the application's URI is concated to the front with a "/" to obtain the absolute URI. Each xnode and xsink element can have zero or more property elements. Each property element has a name attribute and a value attribute, which set the parameter with the given name with the given value. The names and values accepted vary from different types of filter to filter.