com.saxonica.ee.stream.watch

Class WatchManager

java.lang.Object

net.sf.saxon.event.SequenceReceiver

com.saxonica.ee.stream.watch.WatchManager

All Implemented Interfaces:

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.

Field Summary

Fields

Modifier and Type	Field and Description
protected Stack<List<com.saxonica.ee.stream.watch.WatchManager.ClosedownAction>>	activeWatchStack
protected int	elementStackTop
protected 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 and Description
WatchManager(PipelineConfiguration pipe) Create a WatchManager

Method Summary

Methods

Modifier and Type	Method and Description
protected void	addPrearrangedWatches()
void	addWatch(Watch watch) Add a new Watch.
void	append(Item item, Location locationId, int copyNamespaces) Append an arbitrary item (node or atomic value) to the output
void	attribute(NodeName nameCode, SimpleType typeCode, CharSequence value, Location locationId, int properties) Notify an attribute
void	characters(CharSequence chars, Location locationId, int properties) Text node
void	close() Notify the end of the event stream
void	comment(CharSequence chars, Location locationId, int properties) Output a comment
void	endDocument() Notify the end of a document node
void	endElement() Notify end of element
Map<Accumulator,AccumulatorWatch>	getAccumulatorWatchMap() Get a map from accumulators to AccumulatorWatch instances
FleetingDocumentNode	getDocumentNode()
String	getURIForPrefix(String prefix, boolean useDefault) Get the namespace URI corresponding to a given prefix.
XPathContext	getXPathContext()
Iterator<String>	iteratePrefixes() Get an iterator over all the prefixes declared in this namespace context.
void	namespace(NamespaceBinding namespaceBinding, int properties) Notify a namespace
void	processingInstruction(String target, CharSequence data, Location locationId, int properties) Processing Instruction
void	removeWatch(Watch watch) Remove a watch
void	setAccumulatorWatchMap(Map<Accumulator,AccumulatorWatch> accumulatorWatchMap)
void	setStartTagBuffer(StartTagBuffer stb)
void	setXPathContext(XPathContext context)
void	startContent() Start element content (called after all the attributes and namespaces have been processed)
void	startDocument(int properties) Start of a document node.
void	startElement(NodeName elementName, SchemaType typeCode, Location location, int properties) Output element start tag
boolean	usesTypeAnnotations() Ask whether this Receiver (or the downstream pipeline) makes any use of the type annotations supplied on element and attribute events

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

append, getConfiguration, getNamePool, getPipelineConfiguration, getSystemId, isTrueSequenceReceiver, open, setPipelineConfiguration, setSystemId, setUnparsedEntity

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 List<Watch> watchList

activeWatchStack

protected Stack<List<com.saxonica.ee.stream.watch.WatchManager.ClosedownAction>> activeWatchStack

Constructor Detail

WatchManager

public WatchManager(PipelineConfiguration pipe)

Create a WatchManager

Parameters:

pipe - the pipeline configuration

Method Detail

setStartTagBuffer

public void setStartTagBuffer(StartTagBuffer stb)

setXPathContext

public void setXPathContext(XPathContext context)

getXPathContext

public XPathContext getXPathContext()

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 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 NodeInfo.ALL_NAMESPACES, NodeInfo.LOCAL_NAMESPACES, NodeInfo.NO_NAMESPACES

Throws:

XPathException - if the operation fails

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 - bit-significant integer indicating properties of the document node. The definitions of the bits are in class ReceiverOptions

Throws:

XPathException - if an error occurs

startElement

public void startElement(NodeName elementName,
                SchemaType typeCode,
                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.

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 revelant properties, zero is supplied. The definitions of the bits are in class ReceiverOptions

Throws:

XPathException - if an error occurs

addPrearrangedWatches

protected void addPrearrangedWatches()
                              throws XPathException

Throws:

XPathException

attribute

public void attribute(NodeName nameCode,
             SimpleType typeCode,
             CharSequence value,
             Location locationId,
             int properties)
               throws XPathException

Notify an attribute

Specified by:

attribute in interface Receiver

Parameters:

nameCode - integer identifying the name of the attribute

typeCode - integer identifying the type annotation (ignored)

value - the value of the attribute

locationId -

properties - additional properties of the attribute @throws net.sf.saxon.trans.XPathException On any failure to write the attribute

Throws:

XPathException - if an error occurs

namespace

public void namespace(NamespaceBinding namespaceBinding,
             int properties)
               throws XPathException

Notify a namespace

Specified by:

namespace in interface Receiver

Parameters:

namespaceBinding - the prefix/uri pair being notified

properties - properties of this event

Throws:

XPathException - if any error occurs

characters

public void characters(CharSequence 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(CharSequence 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(String target,
                         CharSequence 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

startContent

public void startContent()
                  throws XPathException

Start element content (called after all the attributes and namespaces have been processed)

Specified by:

startContent in interface Receiver

Throws:

XPathException

addWatch

public void addWatch(Watch watch)
              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

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 String getURIForPrefix(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 Iterator<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

getDocumentNode

public FleetingDocumentNode getDocumentNode()

getAccumulatorWatchMap

public Map<Accumulator,AccumulatorWatch> getAccumulatorWatchMap()

Get a map from accumulators to AccumulatorWatch instances

Returns:

the map for all accumulators that apply to this stream. Return null if there are no accumulators

setAccumulatorWatchMap

public void setAccumulatorWatchMap(Map<Accumulator,AccumulatorWatch> accumulatorWatchMap)