org.apache.cocoon.portal.transformation
Class RSSTransformer

java.lang.Object
  org.apache.avalon.framework.logger.AbstractLogEnabled
      org.apache.cocoon.xml.AbstractXMLProducer
          org.apache.cocoon.xml.AbstractXMLPipe
              org.apache.cocoon.transformation.AbstractTransformer
                  org.apache.cocoon.transformation.AbstractSAXTransformer
                      org.apache.cocoon.portal.transformation.RSSTransformer

All Implemented Interfaces:

CacheableProcessingComponent, Configurable, ContentHandler, Disposable, LexicalHandler, LogEnabled, Poolable, Recyclable, Serviceable, SitemapModelComponent, Transformer, XMLConsumer, XMLConsumer, XMLPipe, XMLProducer

public final class RSSTransformer

extends AbstractSAXTransformer

implements CacheableProcessingComponent

This transformer records the content of all description elements and tries to interpret them as valid XML. It's actually a quick hack...

Version:

$Id: RSSTransformer.java 322475 2005-10-16 14:26:44Z cziegeler $

Field Summary

protected XMLDeserializer	deserializer The xml deserializer
protected XMLConsumer	filter The filter
protected XMLizer	xmlizer The xmlizer for converting html to xml

Fields inherited from class org.apache.cocoon.transformation.AbstractSAXTransformer

context, defaultNamespaceURI, EMPTY_ATTRIBUTES, ignoreEmptyCharacters, ignoreEventsCount, ignoreHooksCount, ignoreWhitespaces, manager, namespaceURI, objectModel, parameters, recorderStack, request, resolver, response, source, stack

Fields inherited from class org.apache.cocoon.xml.AbstractXMLProducer

contentHandler, EMPTY_CONTENT_HANDLER, lexicalHandler, xmlConsumer

Fields inherited from interface org.apache.cocoon.transformation.Transformer

ROLE

Constructor Summary

RSSTransformer()

Method Summary

void	endElement(String uri, String name, String raw) receive notification of end element event.
Serializable	getKey() Generate the unique key for the resource being rendered.
SourceValidity	getValidity() Generate the validity object.
void	recycle() Recycle the producer by removing references, and resetting handlers to null (empty) implementations.
void	setup(SourceResolver resolver, Map objectModel, String src, Parameters par) The Sitemap will call the setup() method to prepare the component for use.
void	setupTransforming() Setup the transformation of an xml document.
void	startElement(String uri, String name, String raw, Attributes attributes) receive notification of start element event.

Methods inherited from class org.apache.cocoon.transformation.AbstractSAXTransformer

addRecorder, characters, comment, configure, dispose, endCDATA, endDocument, endDTD, endEntity, endParametersRecording, endParametersRecording, endPrefixMapping, endRecording, endSAXRecording, endSerializedXMLRecording, endTextRecording, endTransformingElement, findPrefixMapping, getMutableAttributes, ignorableWhitespace, processingInstruction, removeRecorder, sendEndElementEvent, sendEndElementEventNS, sendEndPrefixMapping, sendEvents, sendParametersEvents, sendStartElementEvent, sendStartElementEvent, sendStartElementEventNS, sendStartElementEventNS, sendStartPrefixMapping, sendTextEvent, service, setDocumentLocator, skippedEntity, startCDATA, startDocument, startDTD, startEntity, startParametersRecording, startPrefixMapping, startRecording, startSAXRecording, startSerializedXMLRecording, startTextRecording, startTransformingElement

Methods inherited from class org.apache.cocoon.xml.AbstractXMLProducer

setConsumer, setContentHandler, setLexicalHandler

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.cocoon.xml.XMLProducer

setConsumer

Field Detail

xmlizer

protected XMLizer xmlizer

The xmlizer for converting html to xml

deserializer

protected XMLDeserializer deserializer

The xml deserializer

filter

protected XMLConsumer filter

The filter

Constructor Detail

RSSTransformer

public RSSTransformer()

Method Detail

startElement

public void startElement(String uri,
                         String name,
                         String raw,
                         Attributes attributes)
                  throws SAXException

receive notification of start element event.

Specified by:

startElement in interface ContentHandler

Overrides:

startElement in class AbstractSAXTransformer

Throws:

SAXException

See Also:

ContentHandler.startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)

endElement

public void endElement(String uri,
                       String name,
                       String raw)
                throws SAXException

receive notification of end element event.

Specified by:

endElement in interface ContentHandler

Overrides:

endElement in class AbstractSAXTransformer

Throws:

SAXException

See Also:

ContentHandler.endElement(java.lang.String, java.lang.String, java.lang.String)

recycle

public void recycle()

Description copied from class: AbstractXMLProducer

Recycle the producer by removing references, and resetting handlers to null (empty) implementations.

Specified by:

recycle in interface Recyclable

Overrides:

recycle in class AbstractSAXTransformer

setup

public void setup(SourceResolver resolver,
                  Map objectModel,
                  String src,
                  Parameters par)
           throws ProcessingException,
                  SAXException,
                  IOException

Description copied from interface: SitemapModelComponent

The Sitemap will call the setup() method to prepare the component for use. This is where you start the process of getting your information ready to generate your results. See ObjectModelHelper for help with the objectModel.

Specified by:

setup in interface SitemapModelComponent

Overrides:

setup in class AbstractSAXTransformer

Throws:

ProcessingException

SAXException

IOException

setupTransforming

public void setupTransforming()
                       throws IOException,
                              ProcessingException,
                              SAXException

Description copied from class: AbstractSAXTransformer

Setup the transformation of an xml document. This method is called just before the transformation (sending of sax events) starts. It should be used to initialize setup parameter depending on the object modell.

Overrides:

setupTransforming in class AbstractSAXTransformer

Throws:

IOException

ProcessingException

SAXException

getKey

public Serializable getKey()

Description copied from interface: CacheableProcessingComponent

Generate the unique key for the resource being rendered.

The cache key is the single most important part of the caching implementation. If you don't get it right, you can introduce more load on the caching engine than is necessary. It is important that the cache key has the following attributes:

• It must be Serializable (part of the contract of this method).
• It must be Immutable--the key is used as a lookup value.
• It must be Unique within the space of the component (i.e. the key "1" for MyCacheableComponent must be for the same resource every time, but we don't have to worry about the key "1" for YourCacheableComponent).
• The equals() and hashCode() methods must be consistent (i.e. if two keys are equal, the hashCode must also be equal).

Thankfully there is a perfectly suitable object that satisfies these obligations from Java's core: java.lang.String. You can also use your own specific key objects provided they respect the above contracts.

Important:If the cache key is null then your component will not be cached at all. You can use this to your advantage to cache some things but not others.

Specified by:

getKey in interface CacheableProcessingComponent

Returns:

The generated key or null if the component is currently not cacheable.

getValidity

public SourceValidity getValidity()

Description copied from interface: CacheableProcessingComponent

Generate the validity object. This method is invoked after the getKey() method.

The caching contracts use the Excalibur SourceValidity interface to determine whether a resource is valid or not. The validity can be a compound check that incorporates time since creation, parameter values, etc. As long as the sitemap can determine whether the cached resource is valid or not. More information is available on the Apache Excalibur site. Alternatively you can use the built in CacheValidity objects in the org.apache.cocoon.caching package and then use the CacheValidityToSourceValidity adaptor object.

Specified by:

getValidity in interface CacheableProcessingComponent

Returns:

The generated validity object or null if the component is currently not cacheable.