com.saxonica.stream.watch

Class AccumulatorWatch

java.lang.Object

com.saxonica.validate.AbstractWatch

com.saxonica.stream.watch.AccumulatorWatch

All Implemented Interfaces:

Watch

public class AccumulatorWatch
extends AbstractWatch

This watch implements a single accumulator in streaming mode. Unlike other watches, it is called to process every node in the stream; it then checks whether the accumulator has any rule that matches this node, and if so applies the next-value expression associated with that accumulator rule.

Constructor Summary

Constructors

Constructor and Description
AccumulatorWatch(Accumulator accumulator)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() The close() method is called immediately before the Watch is destroyed, that is, when the element whose declaration scopes the constraint implemented by this Watch goes out of scope.
void	endSelectedParentNode(int locationId) Signal that the endElement event has occurred for the element whose startElement event caused the Watch to be activated.
XPathContext	getContext()
Sequence	getPostDescentValue()
Sequence	getPreDescentValue()
void	notifySelectedLeafNode(FleetingNode node, int locationId) Signal that a node (other than an element) that matches the selection has been found.
void	open() Open the watch.
void	setWatchManager(WatchManager watchManager)
Receiver	startSelectedParentNode(FleetingNode node, int locationId) Signal that an element has been found that matches the selection that this Watch is looking for.

Methods inherited from class com.saxonica.validate.AbstractWatch

getAnchorNode, getNamespaceResolver, getPipelineConfiguration, getSelection, setAnchorNode, setNamespaceResolver, setPipelineConfiguration, setSelection

Methods inherited from class java.lang.Object

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

Constructor Detail

AccumulatorWatch

public AccumulatorWatch(Accumulator accumulator)

Method Detail

getContext

public XPathContext getContext()

open

public void open()
          throws XPathException

Description copied from class: AbstractWatch

Open the watch. This is done at the point where it first starts watching for nodes that match the selection.

Specified by:

open in interface Watch

Overrides:

open in class AbstractWatch

Throws:

XPathException

setWatchManager

public void setWatchManager(WatchManager watchManager)

startSelectedParentNode

public Receiver startSelectedParentNode(FleetingNode node,
                               int locationId)
                                 throws XPathException

Signal that an element has been found that matches the selection that this Watch is looking for. This method is called by the WatchManager while processing the startElement event that matches the selection. For this purpose, any attributes selected by the last step in the selection are ignored

Parameters:

node - the element or document node whose start event has been matched

locationId - the location associated with the element or document node (may be the location of the instruction that created it)

Returns:

a Receiver to be notified of all events starting with the startElement/startDocument event for the matched element, and ending with the endElement event for that element; or null if this feature is not required.

Throws:

ValidationException - May be raised if the constraint implemented by this Watch is violated @param locationId

XPathException - May be raised if a dynamic error occurs

notifySelectedLeafNode

public void notifySelectedLeafNode(FleetingNode node,
                          int locationId)
                            throws XPathException

Signal that a node (other than an element) that matches the selection has been found.

Specified by:

notifySelectedLeafNode in interface Watch

Overrides:

notifySelectedLeafNode in class AbstractWatch

Parameters:

node - the node that was matched.

locationId - the location of the node in the source document

Throws:

XPathException

endSelectedParentNode

public void endSelectedParentNode(int locationId)
                           throws XPathException

Signal that the endElement event has occurred for the element whose startElement event caused the Watch to be activated.

Parameters:

locationId - the location of the element

Throws:

ValidationException - May be raised if the constraint implemented by this Watch is violated @param locationId

XPathException - May be raised if a constraint implemented by this Watch is violated

close

public void close()
           throws XPathException

Description copied from class: AbstractWatch

The close() method is called immediately before the Watch is destroyed, that is, when the element whose declaration scopes the constraint implemented by this Watch goes out of scope. The default implementation does nothing.

Specified by:

close in interface Watch

Overrides:

close in class AbstractWatch

Throws:

XPathException

getPreDescentValue

public Sequence getPreDescentValue()

getPostDescentValue

public Sequence getPostDescentValue()