Package com.saxonica.ee.validate

Class FieldWatch

java.lang.Object

com.saxonica.ee.stream.watch.AbstractWatch

com.saxonica.ee.stream.watch.PatternWatch

com.saxonica.ee.validate.FieldWatch

All Implemented Interfaces:

Watch

public class FieldWatch
extends PatternWatch

A FieldWatch is a class that is looking for nodes that match a field selector within a uniqueness or key constraint.

Constructor Summary

Constructors

Constructor	Description
FieldWatch(SelectorWatch parentWatch, Pattern selection, AtomicSequence[] currentRow, int column)	Create a new FieldWatch

Method Summary

Modifier and Type	Method	Description
void	endSelectedParentNode(Location locationId)	Signal that the endElement event has occurred for the element whose startElement event caused the Watch to be activated.
void	processItem(Item item)	Signal that a node (other than an element) that matches the selection has been found.
FieldChecker	startSelectedParentNode(FleetingParentNode node, Location locationId)	Signal that an element has been found that matches the selection that this Watch is looking for.

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

close, getAnchorNode, getSelection, matchesNode, matchesNodesOfKind, open, setAnchorNode, setSelection

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

getNamespaceResolver, getPipelineConfiguration, setNamespaceResolver, setPipelineConfiguration

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldWatch

public FieldWatch(SelectorWatch parentWatch,
                  Pattern selection,
                  AtomicSequence[] currentRow,
                  int column)

Create a new FieldWatch

Parameters:

parentWatch - The SelectorWatch to which field values should be notified

selection - The selection (that is, the restricted XPath expression) used in this field of the constraint

currentRow - represents the selected node whose fields are being evaluated

column - sequence number for this field within the constraint being evaluated

Method Detail

startSelectedParentNode

public FieldChecker startSelectedParentNode(FleetingParentNode node,
                                            Location 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 ConstraintChecker 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 FieldChecker - a receiver that collects the contents of the selected node, or null

Throws:

ValidationException - May be raised if the constraint implemented by this Watch is violated @param locationId the location of the node in the source, or of the instruction that created it

XPathException - May be raised if a dynamic error occurs

endSelectedParentNode

public void endSelectedParentNode(Location locationId)
                           throws ValidationException

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 node in the source, or of the instruction that created it

Throws:

ValidationException - May be raised if the constraint implemented by this Watch is violated @param locationId the location of the node in the source, or of the instruction that created it

processItem

public void processItem(Item item)
                 throws XPathException

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

Specified by:

processItem in interface Watch

Overrides:

processItem in class PatternWatch

Parameters:

item - the node that was matched.

Throws:

XPathException - May be raised if a dynamic error occurs