org.apache.xpath

Class SourceTreeManager

java.lang.Object

org.apache.xpath.SourceTreeManager

public class SourceTreeManager
extends Object

This class bottlenecks all management of source trees. The methods in this class should allow easy garbage collection of source trees (not yet!), and should centralize parsing for those source trees.

Constructor Summary

Constructors

Constructor and Description
SourceTreeManager()

Method Summary

Modifier and Type	Method and Description
String	findURIFromDoc(int owner) Given a document, find the URL associated with that document.
int	getNode(Source source) Given a Source object, find the node associated with it.
int	getSourceTree(Source source, SourceLocator locator, XPathContext xctxt) Get the source tree from the input source.
int	getSourceTree(String base, String urlString, SourceLocator locator, XPathContext xctxt) Get the source tree from the a base URL and a URL string.
URIResolver	getURIResolver() Get the object that will be used to resolve URIs used in document(), etc.
static XMLReader	getXMLReader(Source inputSource, SourceLocator locator) This method returns the SAX2 parser to use with the InputSource obtained from this URI.
int	parseToNode(Source source, SourceLocator locator, XPathContext xctxt) Try to create a DOM source tree from the input source.
void	putDocumentInCache(int n, Source source) Put the source tree root node in the document cache.
void	removeDocumentFromCache(int n) JJK: Support kluge in ElemForEach.
void	reset() Reset the list of SourceTree objects that this manager manages.
Source	resolveURI(String base, String urlString, SourceLocator locator) This will be called by the processor when it encounters an xsl:include, xsl:import, or document() function.
void	setURIResolver(URIResolver resolver) Set an object that will be used to resolve URIs used in document(), etc.

Methods inherited from class java.lang.Object

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

Constructor Detail

SourceTreeManager

public SourceTreeManager()

Method Detail

reset

public void reset()

Reset the list of SourceTree objects that this manager manages.

setURIResolver

public void setURIResolver(URIResolver resolver)

Set an object that will be used to resolve URIs used in document(), etc.

Parameters:

resolver - An object that implements the URIResolver interface, or null.

getURIResolver

public URIResolver getURIResolver()

Get the object that will be used to resolve URIs used in document(), etc.

Returns:

An object that implements the URIResolver interface, or null.

findURIFromDoc

public String findURIFromDoc(int owner)

Given a document, find the URL associated with that document.

Parameters:

owner - Document that was previously processed by this liaison.

Returns:

The base URI of the owner argument.

resolveURI

public Source resolveURI(String base,
                         String urlString,
                         SourceLocator locator)
                  throws TransformerException,
                         IOException

This will be called by the processor when it encounters an xsl:include, xsl:import, or document() function.

Parameters:

base - The base URI that should be used.

urlString - Value from an xsl:import or xsl:include's href attribute, or a URI specified in the document() function.

Returns:

a Source that can be used to process the resource.

Throws:

IOException

TransformerException

removeDocumentFromCache

public void removeDocumentFromCache(int n)

JJK: Support kluge in ElemForEach. TODO: This function is highly dangerous. Cache management must be improved.

Parameters:

n - The node to remove.

putDocumentInCache

public void putDocumentInCache(int n,
                               Source source)

Put the source tree root node in the document cache. TODO: This function needs to be a LOT more sophisticated.

Parameters:

n - The node to cache.

source - The Source object to cache.

getNode

public int getNode(Source source)

Given a Source object, find the node associated with it.

Parameters:

source - The Source object to act as the key.

Returns:

The node that is associated with the Source, or null if not found.

getSourceTree

public int getSourceTree(String base,
                         String urlString,
                         SourceLocator locator,
                         XPathContext xctxt)
                  throws TransformerException

Get the source tree from the a base URL and a URL string.

Parameters:

base - The base URI to use if the urlString is relative.

urlString - An absolute or relative URL string.

locator - The location of the caller, for diagnostic purposes.

Returns:

should be a non-null reference to the node identified by the base and urlString.

Throws:

TransformerException - If the URL can not resolve to a node.

getSourceTree

public int getSourceTree(Source source,
                         SourceLocator locator,
                         XPathContext xctxt)
                  throws TransformerException

Get the source tree from the input source.

Parameters:

source - The Source object that should identify the desired node.

locator - The location of the caller, for diagnostic purposes.

Returns:

non-null reference to a node.

Throws:

TransformerException - if the Source argument can't be resolved to a node.

parseToNode

public int parseToNode(Source source,
                       SourceLocator locator,
                       XPathContext xctxt)
                throws TransformerException

Try to create a DOM source tree from the input source.

Parameters:

source - The Source object that identifies the source node.

locator - The location of the caller, for diagnostic purposes.

Returns:

non-null reference to node identified by the source argument.

Throws:

TransformerException - if the source argument can not be resolved to a source node.

getXMLReader

public static XMLReader getXMLReader(Source inputSource,
                                     SourceLocator locator)
                              throws TransformerException

This method returns the SAX2 parser to use with the InputSource obtained from this URI. It may return null if any SAX2-conformant XML parser can be used, or if getInputSource() will also return null. The parser must be free for use (i.e. not currently in use for another parse().

Parameters:

inputSource - The value returned from the URIResolver.

locator - The location of the original caller, for diagnostic purposes.

Returns:

a SAX2 XMLReader to use to resolve the inputSource argument.

Throws:

TransformerException - if the reader can not be created.