net.sf.saxon.instruct
Class TraceExpression

java.lang.Object
  net.sf.saxon.expr.Expression
      net.sf.saxon.instruct.Instruction
          net.sf.saxon.instruct.TraceWrapper
              net.sf.saxon.instruct.TraceExpression

All Implemented Interfaces:

Serializable, SourceLocator, LocationProvider, SaxonLocator, EvaluableItem, SequenceIterable, TailCallReturner, InstructionInfo, InstructionInfoProvider, Locator

public class TraceExpression
extends TraceWrapper
implements InstructionInfo

A subclass of TraceWrapper used to trace expressions in XPath and XQuery. Unlike the TraceInstruction class, this class contains all information needed for tracing, rather than referencing a separate InstructionDetails object.

See Also:

Serialized Form

Field Summary

Fields inherited from class net.sf.saxon.expr.Expression

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

TraceExpression(Expression child)
Create a trace expression that traces execution of a given child expression

Method Summary

int	getColumnNumber() Get the column number identifying the position of the instruction.
int	getConstructType() Get the construct type.
InstructionInfo	getInstructionInfo() Get the InstructionInfo details about the construct.
int	getLineNumber() Get the line number of the instruction within its module
int	getLineNumber(long locationId) Get the line number of the expression being traced.
NamespaceResolver	getNamespaceResolver() Get the namespace resolver to supply the namespace context of the instruction that is being traced
StructuredQName	getObjectName(NamePool pool) Get a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc.
Iterator	getProperties() Get an iterator over all the properties available.
Object	getProperty(String name) Get a named property of the instruction/expression
String	getSystemId() Get the URI of the module containing the instruction
String	getSystemId(long locationId) Get the system identifier (that is the base URI) of the static context of the expression being traced.
void	setColumnNumber(int column) Set the column number of the expression being traced
void	setConstructType(int type) Set the type of construct.
void	setLineNumber(int line) Set the line number of the expression being traced
void	setNamespaceResolver(NamespaceResolver resolver) Set the namespace context for the instruction being traced.
void	setObjectName(StructuredQName qName) Set a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc.
void	setProperty(String name, Object value) Set a named property of the instruction/expression
void	setSystemId(String systemId) Set the URI of the module containing the instruction

Methods inherited from class net.sf.saxon.instruct.TraceWrapper

computeDependencies, copy, createsNewNodes, evaluateItem, explain, getCardinality, getDependencies, getInstructionNameCode, getItemType, iterate, iterateSubExpressions, optimize, processLeavingTail, promote, replaceSubExpression, simplify, typeCheck

Methods inherited from class net.sf.saxon.instruct.Instruction

computeCardinality, computeSpecialProperties, evaluateAsString, getImplementationMethod, getSourceLocator, isXSLT, process

Methods inherited from class net.sf.saxon.expr.Expression

addToPathMap, adoptChildExpression, checkPermittedContents, computeStaticProperties, display, doPromotion, effectiveBooleanValue, explain, findParentOf, getContainer, getExecutable, getHostLanguage, getIntrinsicDependencies, getLocationId, getLocationProvider, getPublicId, getSlotsUsed, getSpecialProperties, hasLoopingSubexpression, implementsStaticTypeCheck, iterateEvents, markTailFunctionCalls, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.xml.sax.Locator

getPublicId

Methods inherited from interface javax.xml.transform.SourceLocator

getPublicId

Constructor Detail

TraceExpression

public TraceExpression(Expression child)

Create a trace expression that traces execution of a given child expression

Parameters:

child - the expression to be traced. This will be available to the TraceListener as the value of the "expression" property of the InstructionInfo.

Method Detail

setLineNumber

public void setLineNumber(int line)

Set the line number of the expression being traced

Parameters:

line -

setColumnNumber

public void setColumnNumber(int column)

Set the column number of the expression being traced

Parameters:

column -

setConstructType

public void setConstructType(int type)

Set the type of construct. This will generally be a constant in class Location

getConstructType

public int getConstructType()

Get the construct type. This will generally be a constant in class Location

Specified by:

getConstructType in interface InstructionInfo

Returns:

the type of expression, as enumerated in class Location

setNamespaceResolver

public void setNamespaceResolver(NamespaceResolver resolver)

Set the namespace context for the instruction being traced. This is needed if the tracelistener wants to evaluate XPath expressions in the context of the current instruction

getNamespaceResolver

public NamespaceResolver getNamespaceResolver()

Get the namespace resolver to supply the namespace context of the instruction that is being traced

Specified by:

getNamespaceResolver in interface InstructionInfo

setSystemId

public void setSystemId(String systemId)

Set the URI of the module containing the instruction

Parameters:

systemId - the module's URI

getSystemId

public String getSystemId()

Get the URI of the module containing the instruction

Specified by:

getSystemId in interface SourceLocator

Specified by:

getSystemId in interface InstructionInfo

Specified by:

getSystemId in interface Locator

Overrides:

getSystemId in class Expression

Returns:

the module's URI

getLineNumber

public int getLineNumber()

Get the line number of the instruction within its module

Specified by:

getLineNumber in interface SourceLocator

Specified by:

getLineNumber in interface InstructionInfo

Specified by:

getLineNumber in interface Locator

Overrides:

getLineNumber in class Expression

Returns:

the line number

setObjectName

public void setObjectName(StructuredQName qName)

Set a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc. This is used only where the name is known statically.

getObjectName

public StructuredQName getObjectName(NamePool pool)

Get a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc. This is used only where the name is known statically.

Specified by:

getObjectName in interface InstructionInfo

Parameters:

pool -

setProperty

public void setProperty(String name,
                        Object value)

Set a named property of the instruction/expression

getProperty

public Object getProperty(String name)

Get a named property of the instruction/expression

Specified by:

getProperty in interface InstructionInfo

Parameters:

name - The name of the required property

Returns:

The value of the requested property, or null if the property is not available

getProperties

public Iterator getProperties()

Get an iterator over all the properties available. The values returned by the iterator will be of type String, and each string can be supplied as input to the getProperty() method to retrieve the value of the property.

Specified by:

getProperties in interface InstructionInfo

getColumnNumber

public int getColumnNumber()

Get the column number identifying the position of the instruction. This method is provided to satisfy the SourceLocator interface. However, the column number is not maintained by Saxon, and the method always returns -1

Specified by:

getColumnNumber in interface SourceLocator

Specified by:

getColumnNumber in interface Locator

Overrides:

getColumnNumber in class Expression

Returns:

-1

getInstructionInfo

public InstructionInfo getInstructionInfo()

Get the InstructionInfo details about the construct. This is to satisfy the InstructionInfoProvider interface.

Specified by:

getInstructionInfo in interface InstructionInfoProvider

Overrides:

getInstructionInfo in class Instruction

getSystemId

public String getSystemId(long locationId)

Get the system identifier (that is the base URI) of the static context of the expression being traced. This returns the same result as getSystemId(), it is provided to satisfy the LocationProvider interface.

Specified by:

getSystemId in interface LocationProvider

Parameters:

locationId - not used

Returns:

the URI of the module containing the expression

getLineNumber

public int getLineNumber(long locationId)

Get the line number of the expression being traced. This returns the same result as getLineNumber(), it is provided to satisfy the LocationProvider interface.

Specified by:

getLineNumber in interface LocationProvider

Parameters:

locationId - not used

Returns:

the line number of the expression within its module