Package com.sapportals.wcm.service.pipeline.processor

Provides an interface for transforming content from one format to another.

See:
Description

Interface Summary

IProcessor

Transforms the data provided by the producer into another form.

Class Summary

DefaultProcessor

Implementation of a default processor, which can be used to add processing instructions to the xml.

Package com.sapportals.wcm.service.pipeline.processor Description

Provides an interface for transforming content from one format to another.

Package Specification

Purpose
Interfaces and Classes
Implementation Notes
Related Documentation

Purpose

The processor is part of the publishing pipeline. It is responsible for transforming the layout or format of content that has been appropriately prepared. Within the pipeline, an object called a producer prepares content for a transformation by creating an XML DOM or stream and passing this on to the processor. The processor then transforms the format or layout of the content with the help of a stylesheet.

Interfaces and Classes

The processorpackagecontains the IProcessor interface and a DefaultProcessor class. The DefaultProcessor class has a special role that is explained below.

IProcessor
This interface defines a single process method that defines the logic for the transformation of content. Any processor that works together with the publishing pipeline must implement this interface.Different implementations of the interface are available in the KM framework and can be used for different types of transformations. See Implementation Notes.

DefaultProcessor
This class represents a processor that does not transform content, but supplies instructions for the pipeline controller. The pipeline controller is an internal component that supervises the processing steps that are performed by the pipeline on the basis of instructions it finds in an XML file. The instructions state the processor type that must be called, the location of the stylesheet that is to be used and the mime type of the output. If no XML instructions are available, it is the task of the default processor to provide these. It offers methods to add processing instructions to an XML. In most cases the default processor is called internally, within the pipeline. However, when the transformation of a non-XML file is performed, then the default processor must be called explicitly to supply the pipeline with processing instructions.

The example shows instructions that inform the controller to start an XSLT processor, to use the stylesheet page.xsl and to run a formatter program that generates HTML.

<?wcm-process type="xslt"?>
<?xml-stylesheet href="page.xsl" type="text/xsl?">
<?wcm-format type="text/html"?>

Implementation Notes

The KM Platform offers different implementations of processors to serve different purposes. The following processor types are available:

• An HTML processor that merges an HTML input stream with a CSS stylesheet. The result is an HTML with a new layout.
• An XSLT processor that converts an XML DOM with an XSLT stylesheet.
  The result differs depending on the type of stylesheet that is applied.

Note that if the XSLT processor generates an XML DOM for formats like SVG, PDF, HTML or VRML, then a formatter program must complete the transformation process by creating the output format.

Related Documentation

For information on the different components that play role in the publishing pipeline see:
com.sapportals.wcm.service.pipeline
com.sapportals.wcm.service.pipeline.producer
com.sapportals.wcm.service.pipeline.formatter