org.apache.cocoon.generation
Class XPathTraversableGenerator

java.lang.Object
  org.apache.avalon.framework.logger.AbstractLogEnabled
      org.apache.cocoon.xml.AbstractXMLProducer
          org.apache.cocoon.generation.AbstractGenerator
              org.apache.cocoon.generation.ServiceableGenerator
                  org.apache.cocoon.generation.TraversableGenerator
                      org.apache.cocoon.generation.XPathTraversableGenerator

All Implemented Interfaces:

Poolable, Recyclable, Disposable, Component, LogEnabled, Serviceable, CacheableProcessingComponent, Generator, SitemapModelComponent, XMLProducer

public class XPathTraversableGenerator
extends TraversableGenerator

Generates an XML collection listing performing XPath queries on XML sources. It can be used both as a plain TraversableGenerator or, if an XPath is specified, it will perform an XPath query on every XML resource, where "xml resource" is, by default, any resource ending with ".xml", which can be overriden by setting the (regexp) pattern "xmlFiles as a sitemap parameter, or where the name of the resource has a container-wide mime-type mapping to 'text/xml' such as specified by mime-mapping elements in a web.xml descriptor file. The XPath can be specified in two ways:

1. By using an XPointerish syntax in the URL: everything following the pound sign (possiby preceding query string arguments) will be treated as the XPath;
2. Specifying it as a sitemap parameter named "xpath"

Sample usage: Sitemap: <map:match pattern="documents/**"> <map:generate type="xpathdirectory" src=" docs/{1}#/article/title|/article/abstract" > < map:parameter name="xmlFiles" value="\.xml$"/> </map:generate> <map: serialize type="xml" /> </map:match> Request: http://www.some.host/documents/test Result: <collection:collection name="test" lastModified="1010400942000" date="1/7/02 11:55 AM" requested="true" xmlns:collection="http://apache.org/cocoon/collection/1.0"> <collection:collection name="subdirectory" lastModified="1010400942000" date="1/7/02 11:55 AM" /> <collection:resource name="test.xml" lastModified="1011011579000" date="1/14/02 1:32 PM"> <collection:xpath docid="test.xml" query="/article/title"> <title>This is a test document</title> <abstract> <para>Abstract of my test article</para> </abstract> </collection:xpath> </collection:resource> <collection:resource name="test.gif" lastModified="1011011579000" date="1/14/02 1:32 PM"> </collection:collection> If you need to use namespaces, you can set them as sitemap parameters in the form: lt;map:parameter name="xmlns:your prefix" value="nsURI"/**">

Version:

CVS $Id: XPathTraversableGenerator.html 1304258 2012-03-23 10:09:27Z ilgrosso $

Author:

Gianugo Rabellino, Daniele Madama

Field Summary

protected Context	context The cocoon context used for mime-type mappings
protected Document	doc The document that should be parsed and (partly) included.
protected org.apache.cocoon.generation.XPathTraversableGenerator.XPathPrefixResolver	prefixResolver The prefix resolver for namespaced queries
protected XPathProcessor	processor The XPath processor.
protected static String	QUERY_ATTR_NAME Attribute for the XPath query.
protected static String	RESULT_DOCID_ATTR The document containing a successful XPath query
protected org.apache.regexp.RE	xmlRE The regular expression for the XML files pattern.
protected String	xpath The XPath.
protected static String	XPATH_NODE_NAME Local name for the element that contains the included XML snippet.

Fields inherited from class org.apache.cocoon.generation.TraversableGenerator

attributes, cacheKeyParList, COL_NODE_NAME, DATE_ATTR_NAME, dateFormatter, depth, excludeRE, includeRE, isRequestedSource, LASTMOD_ATTR_NAME, PREFIX, refreshDelay, RES_NAME_ATTR_NAME, RESOURCE_NODE_NAME, reverse, rootRE, SIZE_ATTR_NAME, sort, URI, URI_ATTR_NAME, validity

Fields inherited from class org.apache.cocoon.generation.ServiceableGenerator

manager

Fields inherited from class org.apache.cocoon.generation.AbstractGenerator

objectModel, parameters, resolver, source

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

contentHandler, EMPTY_CONTENT_HANDLER, lexicalHandler, xmlConsumer

Fields inherited from interface org.apache.cocoon.generation.Generator

ROLE

Constructor Summary

XPathTraversableGenerator()

Method Summary

protected void	addContent(TraversableSource source) Allow subclasses a chance to generate additional elements within collection and resource elements.
void	dispose() Release all resources.
protected boolean	isXML(TraversableSource path) Determines if a given TraversableSource shall be handled as XML.
protected void	performXPathQuery(TraversableSource in) Performs an XPath query on the source.
void	recycle() Recycle resources
void	service(ServiceManager manager) Set the current ServiceManager instance used by this Serviceable.
void	setup(SourceResolver resolver, Map objectModel, String src, Parameters par) Set the request parameters.

Methods inherited from class org.apache.cocoon.generation.TraversableGenerator

addAncestorPath, addPath, endNode, generate, getAncestors, getKey, getValidity, isExcluded, isIncluded, isRoot, setNodeAttributes, startNode

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

XPATH_NODE_NAME

protected static final String XPATH_NODE_NAME

Local name for the element that contains the included XML snippet.

See Also:

Constant Field Values

QUERY_ATTR_NAME

protected static final String QUERY_ATTR_NAME

Attribute for the XPath query.

See Also:

Constant Field Values

RESULT_DOCID_ATTR

protected static final String RESULT_DOCID_ATTR

The document containing a successful XPath query

See Also:

Constant Field Values

xmlRE

protected org.apache.regexp.RE xmlRE

The regular expression for the XML files pattern.

doc

protected Document doc

The document that should be parsed and (partly) included.

xpath

protected String xpath

The XPath.

processor

protected XPathProcessor processor

The XPath processor.

prefixResolver

protected org.apache.cocoon.generation.XPathTraversableGenerator.XPathPrefixResolver prefixResolver

The prefix resolver for namespaced queries

context

protected Context context

The cocoon context used for mime-type mappings

Constructor Detail

XPathTraversableGenerator

public XPathTraversableGenerator()

Method Detail

setup

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

Description copied from class: TraversableGenerator

Set the request parameters. Must be called before the generate method.

Specified by:

setup in interface SitemapModelComponent

Overrides:

setup in class TraversableGenerator

Parameters:

resolver - the SourceResolver object

objectModel - a Map containing model object

src - the Traversable Source to be XMLized specified as src attribute on <map:generate/>

par - configuration parameters

Throws:

ProcessingException

SAXException

IOException

service

public void service(ServiceManager manager)
             throws ServiceException

Description copied from class: ServiceableGenerator

Set the current ServiceManager instance used by this Serviceable.

Specified by:

service in interface Serviceable

Overrides:

service in class ServiceableGenerator

Throws:

ServiceException

dispose

public void dispose()

Description copied from class: ServiceableGenerator

Release all resources.

Specified by:

dispose in interface Disposable

Overrides:

dispose in class ServiceableGenerator

addContent

protected void addContent(TraversableSource source)
                   throws SAXException,
                          ProcessingException

Description copied from class: TraversableGenerator

Allow subclasses a chance to generate additional elements within collection and resource elements.

Overrides:

addContent in class TraversableGenerator

Parameters:

source - the source to generate additional data for.

Throws:

SAXException

ProcessingException

isXML

protected boolean isXML(TraversableSource path)

Determines if a given TraversableSource shall be handled as XML.

Parameters:

path - the TraversableSource to check

Returns:

true if the given TraversableSource shall handled as XML, false otherwise.

performXPathQuery

protected void performXPathQuery(TraversableSource in)
                          throws SAXException

Performs an XPath query on the source.

Parameters:

in - the Source the XPath is performed on.

Throws:

SAXException - if something goes wrong while adding the XML snippet.

recycle

public void recycle()

Recycle resources

Specified by:

recycle in interface Recyclable

Overrides:

recycle in class TraversableGenerator