net.sf.saxon.event
Class NamespaceReducer

java.lang.Object
  net.sf.saxon.event.SequenceReceiver
      net.sf.saxon.event.ProxyReceiver
          net.sf.saxon.event.NamespaceReducer

All Implemented Interfaces:

Result, Receiver, NamespaceResolver

public class NamespaceReducer
extends ProxyReceiver
implements NamespaceResolver

NamespaceReducer is a ProxyReceiver responsible for removing duplicate namespace declarations. It also ensures that an xmlns="" undeclaration is output when necessary. Used on its own, the NamespaceReducer simply eliminates unwanted namespace declarations. It can also be subclassed, in which case the subclass can use the services of the NamespaceReducer to resolve QNames.

The NamespaceReducer also validates namespace-sensitive content.

Field Summary

Fields inherited from class net.sf.saxon.event.ProxyReceiver

nextReceiver

Fields inherited from class net.sf.saxon.event.SequenceReceiver

pipelineConfiguration, previousAtomic, systemId

Fields inherited from interface javax.xml.transform.Result

PI_DISABLE_OUTPUT_ESCAPING, PI_ENABLE_OUTPUT_ESCAPING

Constructor Summary

NamespaceReducer()
Create a NamespaceReducer

NamespaceReducer(Receiver base)
Create a NamespaceReducer with a given destination Receiver

Method Summary

void	endElement() endElement: Discard the namespaces declared on this element.
protected short	getURICode(short prefixCode) Get the URI code corresponding to a given prefix code, by searching the in-scope namespaces.
String	getURIForPrefix(String prefix, boolean useDefault) Get the namespace URI corresponding to a given prefix.
Iterator	iteratePrefixes() Get an iterator over all the prefixes declared in this namespace context.
void	namespace(int namespaceCode, int properties) Output a namespace node (binding)
void	startContent() startContent: Add any namespace undeclarations needed to stop namespaces being inherited from parent elements
void	startElement(int nameCode, int typeCode, int locationId, int properties) startElement.

Methods inherited from class net.sf.saxon.event.ProxyReceiver

append, attribute, characters, close, comment, endDocument, getConfiguration, getDocumentLocator, getNamePool, getUnderlyingReceiver, open, processingInstruction, setPipelineConfiguration, setSystemId, setUnderlyingReceiver, setUnparsedEntity, startDocument, usesTypeAnnotations

Methods inherited from class net.sf.saxon.event.SequenceReceiver

getPipelineConfiguration, getSystemId

Methods inherited from class java.lang.Object

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

Constructor Detail

NamespaceReducer

public NamespaceReducer()

Create a NamespaceReducer

NamespaceReducer

public NamespaceReducer(Receiver base)

Create a NamespaceReducer with a given destination Receiver

Parameters:

base - the Receiver to which events will be passed after namespace reduction

Method Detail

startElement

public void startElement(int nameCode,
                         int typeCode,
                         int locationId,
                         int properties)
                  throws XPathException

startElement. This call removes redundant namespace declarations, and possibly adds an xmlns="" undeclaration.

Specified by:

startElement in interface Receiver

Overrides:

startElement in class ProxyReceiver

Parameters:

nameCode - integer code identifying the name of the element within the name pool.

typeCode - integer code identifying the element's type within the name pool.

locationId - an integer which can be interpreted using a LocationProvider to return information such as line number and system ID. If no location information is available, the value zero is supplied.

properties - properties of the element node

Throws:

XPathException

namespace

public void namespace(int namespaceCode,
                      int properties)
               throws XPathException

Output a namespace node (binding)

Specified by:

namespace in interface Receiver

Overrides:

namespace in class ProxyReceiver

Parameters:

namespaceCode - encapsulates the prefix and URI

properties - the properties of the namespace binding

Throws:

XPathException

startContent

public void startContent()
                  throws XPathException

startContent: Add any namespace undeclarations needed to stop namespaces being inherited from parent elements

Specified by:

startContent in interface Receiver

Overrides:

startContent in class ProxyReceiver

Throws:

XPathException

endElement

public void endElement()
                throws XPathException

endElement: Discard the namespaces declared on this element.

Specified by:

endElement in interface Receiver

Overrides:

endElement in class ProxyReceiver

Throws:

XPathException

getURICode

protected short getURICode(short prefixCode)

Get the URI code corresponding to a given prefix code, by searching the in-scope namespaces. This is a service provided to subclasses.

Parameters:

prefixCode - the 16-bit prefix code required

Returns:

the 16-bit URI code, or -1 if the prefix is not found

getURIForPrefix

public String getURIForPrefix(String prefix,
                              boolean useDefault)

Get the namespace URI corresponding to a given prefix. Return null if the prefix is not in scope.

Specified by:

getURIForPrefix in interface NamespaceResolver

Parameters:

prefix - the namespace prefix

useDefault - true if the default namespace is to be used when the prefix is ""

Returns:

the uri for the namespace, or null if the prefix is not in scope

iteratePrefixes

public Iterator iteratePrefixes()

Get an iterator over all the prefixes declared in this namespace context. This will include the default namespace (prefix="") and the XML namespace where appropriate

Specified by:

iteratePrefixes in interface NamespaceResolver