com.saxonica.validate
Class SelectorWatch

java.lang.Object
  extended by com.saxonica.validate.AbstractWatch
      extended by com.saxonica.validate.SelectorWatch
All Implemented Interfaces:
Watch
Direct Known Subclasses:
KeySelectorWatch, RefSelectorWatch

public abstract class SelectorWatch
extends AbstractWatch
implements Watch

A Watch represents a class that is interested in looking at nodes for the purpose of evaluating uniqueness and key constraints. A SelectorWatch looks for the nodes that match the selector in a unique, key, or keyref constraint. There are two concrete subclasses: one for key/unique, the other for keyref


Constructor Summary
SelectorWatch(ConstraintChecker checker, IdentityConstraint uniqueConstraint)
           
 
Method Summary
 void addFieldValue(Value[] currentRow, int column, Value value, boolean nillableElement, long locationId)
          The addFieldValue method is a callback from the FieldWatch created when this SelectorWatch is activated.
protected  void checkRow(Value[] currentRow, boolean isTarget, int locationId)
          Method to check that a row (that is, the collection of fields corresponding to one selected node) is valid.
 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.
protected  String displayRow(Value[] row)
          Internal method to display the contents of a row, for diagnostics
 void endSelectedParentNode(int locationId)
          Signal that the endElement event has occurred for the element whose startElement event caused the Watch to be activated.
 IdentityConstraint getIdentityConstraint()
          Get the identityConstraint implemented by this SelectorWatch
protected  void reportValidationError(ValidationException err, long locationId)
          Report a validation error
protected  void reportValidationError(ValidationException err, SourceLocator locator)
          Report a validation error
 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, notifySelectedLeafNode, open, setAnchorNode, setNamespaceResolver, setPipelineConfiguration, setSelection
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface com.saxonica.stream.watch.Watch
getAnchorNode, getNamespaceResolver, getPipelineConfiguration, getSelection, notifySelectedLeafNode, open, setAnchorNode, setNamespaceResolver, setPipelineConfiguration, setSelection
 

Constructor Detail

SelectorWatch

public SelectorWatch(ConstraintChecker checker,
                     IdentityConstraint uniqueConstraint)
Method Detail

getIdentityConstraint

public IdentityConstraint getIdentityConstraint()
Get the identityConstraint implemented by this SelectorWatch


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 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

Specified by:
startSelectedParentNode in interface Watch
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 events for the subtree rooted at the element matched by this Watch. A SelectorWatch does not require such notification, so it returns null. @param locationId
Throws:
ValidationException - May be raised if the constraint implemented by this Watch is violated
XPathException

endSelectedParentNode

public void endSelectedParentNode(int locationId)
                           throws ValidationException
Signal that the endElement event has occurred for the element whose startElement event caused the Watch to be activated.

Specified by:
endSelectedParentNode in interface Watch
Parameters:
locationId - the location of the element
Throws:
ValidationException - May be raised if the constraint implemented by this Watch is violated @param locationId

close

public void close()
           throws ValidationException
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.

Specified by:
close in interface Watch
Overrides:
close in class AbstractWatch
Throws:
ValidationException

addFieldValue

public void addFieldValue(Value[] currentRow,
                          int column,
                          Value value,
                          boolean nillableElement,
                          long locationId)
                   throws ValidationException
The addFieldValue method is a callback from the FieldWatch created when this SelectorWatch is activated. It indicates that a value for one of the fields participating in this constraint has been encountered.

Parameters:
currentRow - identifying the node to which this field value applies
column - identifies which of the fields participating in this constraint the value relates to
value - The value of the field that was encountered
nillableElement - True if the field represents a nillable element
locationId - the location of the data in the source document
Throws:
ValidationException - May be raised if the value of the field violates the constraint

checkRow

protected void checkRow(Value[] currentRow,
                        boolean isTarget,
                        int locationId)
                 throws ValidationException
Method to check that a row (that is, the collection of fields corresponding to one selected node) is valid.

Parameters:
currentRow - the values of the set of fields
isTarget - set to true if this is a value of the key referred to by a key reference, rather than a value for this constraint's own selected fields.
locationId - identifies the location of the selected node
Throws:
ValidationException - is raised if the value of the row (that is, the combination of fields) violates the constraint

displayRow

protected String displayRow(Value[] row)
Internal method to display the contents of a row, for diagnostics


reportValidationError

protected void reportValidationError(ValidationException err,
                                     long locationId)
                              throws ValidationException
Report a validation error

Parameters:
err - The validation exception
locationId - identifies the location in the source document or stylesheet/query where the validation error was detected
Throws:
ValidationException

reportValidationError

protected void reportValidationError(ValidationException err,
                                     SourceLocator locator)
                              throws ValidationException
Report a validation error

Parameters:
err - The validation exception
locator - identifies the location in the source document or stylesheet/query where the validation error was detected
Throws:
ValidationException


Copyright (c) 2004-2011 Saxonica Limited. All rights reserved.