com.saxonica.ee.stream.watch

Class ForEachGroupAction

java.lang.Object

com.saxonica.ee.stream.feed.ItemFeed

com.saxonica.ee.stream.watch.ForEachAction

com.saxonica.ee.stream.watch.ForEachGroupAction

All Implemented Interfaces:

Feed

public class ForEachGroupAction
extends ForEachAction

This watch implements xsl:for-each-group in streaming mode. It is informed of the nodes or other items selected by the xsl:for-each instruction; when such an item is encountered, it locates the relevant (inverted) action representing the body of the for-each, and activates it.

The feed is capable of handling a select expression that selects non-peer nodes (that is, one selected node that is a descendant of another). A top-level selected node is processed directly to the output receiver; a nested node is processed to create a temporary result tree, which is then appended to the output sequence when the processing of the outer selected node is complete.

Nested Class Summary

Nested classes/interfaces inherited from class com.saxonica.ee.stream.watch.ForEachAction

ForEachAction.Activation

Field Summary

Fields inherited from class com.saxonica.ee.stream.watch.ForEachAction

bodyContext

Constructor Summary

Constructors

Constructor and Description
ForEachGroupAction(WatchManager watchManager, ForEachGroup expression, Feed result, XPathContext context)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Finish evaluating the expression.
void	endSelectedParentNode(int locationId) Signal that the endElement event has occurred for the element whose startElement event caused the Watch to be activated.
protected void	makeBodyContext()
void	open(Terminator terminator) Start evaluating the expression.
void	processItem(Item node) Signal that an item (other than an element) that matches the selection has been found.
Receiver	startSelectedParentNode(FleetingParentNode node, int locationId) Signal that an element (or document node) has been found that matches the selection that this Watch is looking for.

Methods inherited from class com.saxonica.ee.stream.watch.ForEachAction

getAction, getActivationStack, getBodyContext, getInversion, getValuesAwaitingOutput, getWatchManager, isActionConsuming, setInversion

Methods inherited from class com.saxonica.ee.stream.feed.ItemFeed

dynamicError, getContext, getExpression, getPipelineConfiguration, getReceiver, getResult, getTerminator, hasFailed, processItems, setExpression, setHasFailed, setPipelineConfiguration, setTerminator

Methods inherited from class java.lang.Object

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

Constructor Detail

ForEachGroupAction

public ForEachGroupAction(WatchManager watchManager,
                  ForEachGroup expression,
                  Feed result,
                  XPathContext context)

Method Detail

open

public void open(Terminator terminator)
          throws XPathException

Description copied from class: ItemFeed

Start evaluating the expression. The default implementation does nothing.

Specified by:

open in interface Feed

Overrides:

open in class ForEachAction

Parameters:

terminator - used to achieve early exit

Throws:

XPathException - if a dynamic error occurs

makeBodyContext

protected void makeBodyContext()

Overrides:

makeBodyContext in class ForEachAction

startSelectedParentNode

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

Signal that an element (or document node) 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

Specified by:

startSelectedParentNode in interface Feed

Overrides:

startSelectedParentNode in class ForEachAction

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:

XPathException - if a dynamic error occurs while processing the start-element event

processItem

public void processItem(Item node)
                 throws XPathException

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

Specified by:

processItem in interface Feed

Overrides:

processItem in class ForEachAction

Parameters:

node - the item that was matched.

Throws:

XPathException - May be raised if a dynamic error occurs

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.

Specified by:

endSelectedParentNode in interface Feed

Overrides:

endSelectedParentNode in class ForEachAction

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: ItemFeed

Finish evaluating the expression. The default implementation does nothing.

Specified by:

close in interface Feed

Overrides:

close in class ForEachAction

Throws:

XPathException - if a dynamic error occurs