Package com.saxonica.ee.stream.watch

Class WatchManager

java.lang.Object

net.sf.saxon.event.SequenceReceiver

com.saxonica.ee.stream.watch.WatchManager

All Implemented Interfaces:

javax.xml.transform.Result, Receiver, NamespaceResolver

Direct Known Subclasses:

ConstraintChecker

public class WatchManager
extends SequenceReceiver
implements NamespaceResolver

This class sits on a push pipeline and evaluates the passing element and attribute nodes. One or more Watch objects can be registered with the pipeline at any time; element and attribute events are notified to the active Watch objects. A watch that is added immediately after a startElement call is automatically dropped at the corresponding endElement call. If a Watch matches a startElement call, then it becomes an active Watch; it is automatically deactivated (but not dropped) at the corresponding endElement call.

A Watch is not itself a receiver, but it can nominate a Receiver to receive all events while it is active. It will stop receiving events when it is deactivated.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	WatchManager.ClosedownAction
static class	WatchManager.GroupingScope

Field Summary

Fields

Modifier and Type	Field	Description
protected java.util.Stack<java.util.List<WatchManager.ClosedownAction>>	activeWatchStack
protected int	elementStackTop
protected java.util.List<Watch>	watchList

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

Constructors

Constructor	Description
WatchManager(PipelineConfiguration pipe)	Create a WatchManager

Method Summary

Modifier and Type	Method	Description
protected void	addPrearrangedWatches()
void	addWatch(Watch watch, boolean autoClose)	Add a new Watch.
boolean	allowsEarlyExit()
void	append(Item item, Location locationId, int copyNamespaces)	Append an arbitrary item (node or atomic value) to the output
void	characters(UnicodeString chars, Location locationId, int properties)	Text node
void	close()	Notify the end of the event stream
void	comment(UnicodeString chars, Location locationId, int properties)	Output a comment
void	endDocument()	Notify the end of a document node
void	endElement()	Notify end of element
void	endGroupingScope(WatchManager.GroupingScope current)	Called during a partitioning for-each-group whenever a group is closed
long	getCurrentEventNumber()
FleetingParentNode	getCurrentNode()
int	getDepth()
FleetingDocumentNode	getDocumentNode()
MultiAccumulatorWatch	getMultiAccumulatorWatch()
Outputter	getOutputter()
NamespaceUri	getURIForPrefix(java.lang.String prefix, boolean useDefault)	Get the namespace URI corresponding to a given prefix.
XPathContext	getXPathContext()
java.util.Iterator<java.lang.String>	iteratePrefixes()	Get an iterator over all the prefixes declared in this namespace context.
void	processingInstruction(java.lang.String target, UnicodeString data, Location locationId, int properties)	Processing Instruction
void	removeWatch(Watch watch)	Remove a watch
void	restartElement(Watch watch)	During schema validation, the startElement() event is emitted before we can examine all the streamed assertions that might apply to that element.
void	setOutputter(Outputter outputter)
void	setUnparsedEntity(java.lang.String name, java.lang.String systemID, java.lang.String publicID)	Notify an unparsed entity URI.
void	setXPathContext(XPathContext context)
void	startCapturingGroupingWatches(WatchManager.GroupingScope scope)
void	startDocument(int properties)	Start of a document node.
void	startElement(NodeName elementName, SchemaType typeCode, AttributeMap attributes, NamespaceMap namespaces, Location location, int properties)	Output element start tag
WatchManager.GroupingScope	startGroupingScope()	Called during a partitioning for-each-group whenever a new group is started
void	stopCapturingGroupingWatches(WatchManager.GroupingScope scope)
boolean	usesTypeAnnotations()	Ask whether this Receiver (or the downstream pipeline) makes any use of the type annotations supplied on element and attribute events
void	watchAccumulators(MultiAccumulatorWatch multiWatch)

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

append, decompose, flatten, getConfiguration, getErrorCodeForDecomposingFunctionItems, getNamePool, getPipelineConfiguration, getSystemId, handlesAppend, open, setPipelineConfiguration, setSystemId

Methods inherited from class java.lang.Object

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

Field Detail

elementStackTop

protected int elementStackTop

watchList

protected java.util.List<Watch> watchList

activeWatchStack

protected java.util.Stack<java.util.List<WatchManager.ClosedownAction>> activeWatchStack

Constructor Detail

WatchManager

public WatchManager(PipelineConfiguration pipe)

Create a WatchManager

Parameters:

pipe - the pipeline configuration

Method Detail

setXPathContext

public void setXPathContext(XPathContext context)

getXPathContext

public XPathContext getXPathContext()

setOutputter

public void setOutputter(Outputter outputter)

getOutputter

public Outputter getOutputter()

append

public void append(Item item,
                   Location locationId,
                   int copyNamespaces)
            throws XPathException

Append an arbitrary item (node or atomic value) to the output

Specified by:

append in interface Receiver

Specified by:

append in class SequenceReceiver

Parameters:

item - the item to be appended

locationId - the location of the calling instruction, for diagnostics

copyNamespaces - if the item is an element node, this indicates whether its namespaces need to be copied. Values are ReceiverOption.ALL_NAMESPACES; the default (0) means

Throws:

XPathException - if an error occurs

close

public void close()
           throws XPathException

Notify the end of the event stream

Specified by:

close in interface Receiver

Throws:

XPathException - if an error occurs

startDocument

public void startDocument(int properties)
                   throws XPathException

Start of a document node.

Specified by:

startDocument in interface Receiver

Parameters:

properties - properties of the document node

Throws:

XPathException - if an error occurs

startElement

public void startElement(NodeName elementName,
                         SchemaType typeCode,
                         AttributeMap attributes,
                         NamespaceMap namespaces,
                         Location location,
                         int properties)
                  throws XPathException

Output element start tag

Specified by:

startElement in interface Receiver

Parameters:

elementName - the name of the element.

typeCode - the type annotation of the element.

attributes - the attributes of this element

namespaces - the in-scope namespaces of this element: generally this is all the in-scope namespaces, without relying on inheriting namespaces from parent elements

location - an object providing information about the module, line, and column where the node originated

properties - bit-significant properties of the element node. If there are no relevant properties, zero is supplied. The definitions of the bits are in class ReceiverOption

Throws:

XPathException - if an error occurs

restartElement

public void restartElement(Watch watch)
                    throws XPathException

During schema validation, the startElement() event is emitted before we can examine all the streamed assertions that might apply to that element. So this method can be used to process a Watch against the most recent start element event, on the basis that we might have missed it the first time round.

Throws:

XPathException

getDepth

public int getDepth()

getCurrentNode

public FleetingParentNode getCurrentNode()

getCurrentEventNumber

public long getCurrentEventNumber()

addPrearrangedWatches

protected void addPrearrangedWatches()
                              throws XPathException

Throws:

XPathException

characters

public void characters(UnicodeString chars,
                       Location locationId,
                       int properties)
                throws XPathException

Text node

Specified by:

characters in interface Receiver

Parameters:

chars - The characters

locationId - provides information such as line number and system ID.

properties - Bit significant value. The following bits are defined:

DISABLE_ESCAPING

Disable escaping for this text node

USE_CDATA

Output as a CDATA section

Throws:

XPathException - if an error occurs

endElement

public void endElement()
                throws XPathException

Notify end of element

Specified by:

endElement in interface Receiver

Throws:

XPathException - if an error occurs

endDocument

public void endDocument()
                 throws XPathException

Notify the end of a document node

Specified by:

endDocument in interface Receiver

Throws:

XPathException - if an error occurs

comment

public void comment(UnicodeString chars,
                    Location locationId,
                    int properties)
             throws XPathException

Output a comment

Specified by:

comment in interface Receiver

Parameters:

chars - The content of the comment

locationId - provides information such as line number and system ID.

properties - Additional information about the comment.

Throws:

XPathException - if an error occurs

processingInstruction

public void processingInstruction(java.lang.String target,
                                  UnicodeString data,
                                  Location locationId,
                                  int properties)
                           throws XPathException

Processing Instruction

Specified by:

processingInstruction in interface Receiver

Parameters:

target - The PI name. This must be a legal name (it will not be checked).

data - The data portion of the processing instruction

locationId - provides information such as line number and system ID.

properties - Additional information about the PI.

Throws:

XPathException - if an error occurs

setUnparsedEntity

public void setUnparsedEntity(java.lang.String name,
                              java.lang.String systemID,
                              java.lang.String publicID)
                       throws XPathException

Notify an unparsed entity URI.

Specified by:

setUnparsedEntity in interface Receiver

Overrides:

setUnparsedEntity in class SequenceReceiver

Parameters:

name - The name of the unparsed entity

systemID - The system identifier of the unparsed entity

publicID - The public identifier of the unparsed entity

Throws:

XPathException - if an error occurs

addWatch

public void addWatch(Watch watch,
                     boolean autoClose)
              throws XPathException

Add a new Watch. This is associated with the current level in the element stack, and is automatically closed and dropped when the current element goes out of scope.

Parameters:

watch - the watch to be added

autoClose - set to true if the watch is to be automatically opened as soon as it is registered, and is to be automatically closed when it goes out of scope.

Throws:

XPathException - if any error occurs

removeWatch

public void removeWatch(Watch watch)

Remove a watch

Parameters:

watch - the watch to be removed. No error occurs if the watch is unknown or inactive.

getURIForPrefix

public NamespaceUri getURIForPrefix(java.lang.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. May be the zero-length string, indicating that there is no prefix. This indicates either the default namespace or the null namespace, depending on the value of useDefault.

useDefault - true if the default namespace is to be used when the prefix is "". If false, the method returns "" when the prefix is "".

Returns:

the uri for the namespace, or null if the prefix is not in scope. The "null namespace" is represented by the pseudo-URI "".

iteratePrefixes

public java.util.Iterator<java.lang.String> iteratePrefixes()

Description copied from interface: NamespaceResolver

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

Returns:

an iterator over all the prefixes for which a namespace binding exists, including the zero-length string to represent the null/absent prefix if it is bound

usesTypeAnnotations

public boolean usesTypeAnnotations()

Ask whether this Receiver (or the downstream pipeline) makes any use of the type annotations supplied on element and attribute events

Specified by:

usesTypeAnnotations in interface Receiver

Returns:

true if the Receiver makes any use of this information. If false, the caller may supply untyped nodes instead of supplying the type annotation

allowsEarlyExit

public boolean allowsEarlyExit()

getDocumentNode

public FleetingDocumentNode getDocumentNode()

getMultiAccumulatorWatch

public MultiAccumulatorWatch getMultiAccumulatorWatch()

watchAccumulators

public void watchAccumulators(MultiAccumulatorWatch multiWatch)
                       throws XPathException

Throws:

XPathException

startGroupingScope

public WatchManager.GroupingScope startGroupingScope()

Called during a partitioning for-each-group whenever a new group is started

endGroupingScope

public void endGroupingScope(WatchManager.GroupingScope current)
                      throws XPathException

Called during a partitioning for-each-group whenever a group is closed

Throws:

XPathException - if a failure occurs

startCapturingGroupingWatches

public void startCapturingGroupingWatches(WatchManager.GroupingScope scope)

stopCapturingGroupingWatches

public void stopCapturingGroupingWatches(WatchManager.GroupingScope scope)