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:

java.io.Serializable, javax.xml.transform.SourceLocator, LocationProvider, SaxonLocator, EvaluableItem, SequenceIterable, TailCallReturner, InstructionInfo, org.xml.sax.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, locationId, PROCESS_METHOD, staticProperties

Constructor Summary

Constructors
Constructor Description

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

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`getColumnNumber()`	Get the column number identifying the position of the instruction.
`int`	`getColumnNumber(long locationId)`	Get the column number within the document or module containing a particular location
`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()`	Get a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc.
`java.util.Iterator`	`getProperties()`	Get an iterator over all the properties available.
`java.lang.Object`	`getProperty(java.lang.String name)`	Get a named property of the instruction/expression
`java.lang.String`	`getSystemId()`	Get the URI of the module containing the instruction
`java.lang.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(java.lang.String name, java.lang.Object value)`	Set a named property of the instruction/expression
`void`	`setSystemId(java.lang.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
assembleParams, assembleTunnelParams, computeCardinality, computeSpecialProperties, dynamicError, evaluateAsString, getImplementationMethod, getSourceLocator, isXSLT, process, promoteInst

Methods inherited from class java.lang.Object
clone, equals, finalize, 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
    
    Overrides:
    
    getConstructType in class Instruction
    
    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
  - setSystemId
```
public void setSystemId(java.lang.String systemId)
```
    Set the URI of the module containing the instruction
    
    Parameters:
    
    systemId - the module's URI
  - getSystemId
```
public java.lang.String getSystemId()
```
    Get the URI of the module containing the instruction
    
    Specified by:
    
    getSystemId in interface InstructionInfo
    
    Specified by:
    
    getSystemId in interface org.xml.sax.Locator
    
    Specified by:
    
    getSystemId in interface javax.xml.transform.SourceLocator
    
    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 InstructionInfo
    
    Specified by:
    
    getLineNumber in interface org.xml.sax.Locator
    
    Specified by:
    
    getLineNumber in interface javax.xml.transform.SourceLocator
    
    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()
```
    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
    
    Overrides:
    
    getObjectName in class Expression
    
    Returns:
    
    the QName of the object declared or manipulated by this instruction or expression
  - setProperty
```
public void setProperty(java.lang.String name,
                        java.lang.Object value)
```
    Set a named property of the instruction/expression
  - getProperty
```
public java.lang.Object getProperty(java.lang.String name)
```
    Get a named property of the instruction/expression
    
    Specified by:
    
    getProperty in interface InstructionInfo
    
    Overrides:
    
    getProperty in class Expression
    
    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 java.util.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
    
    Overrides:
    
    getProperties in class Expression
    
    Returns:
    
    an iterator over the properties.
  - 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 org.xml.sax.Locator
    
    Specified by:
    
    getColumnNumber in interface javax.xml.transform.SourceLocator
    
    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.
    
    Overrides:
    
    getInstructionInfo in class TraceWrapper
    
    Returns:
    
    the details of the child instruction (the instruction being traced)
  - getSystemId
```
public java.lang.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
    
    Overrides:
    
    getSystemId in class Expression
    
    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
    
    Overrides:
    
    getLineNumber in class Expression
    
    Parameters:
    
    locationId - not used
    
    Returns:
    
    the line number of the expression within its module
  - getColumnNumber
```
public int getColumnNumber(long locationId)
```
    Description copied from interface: LocationProvider
    
    Get the column number within the document or module containing a particular location
    
    Specified by:
    
    getColumnNumber in interface LocationProvider
    
    Overrides:
    
    getColumnNumber in class Expression
    
    Parameters:
    
    locationId - identifier of the location in question (as passed down the Receiver pipeline)
    
    Returns:
    
    the column number within the document or module, or -1 if this is not available

Class TraceExpression

Field Summary

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

Constructor Summary

Method Summary

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

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

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

Methods inherited from class java.lang.Object

Methods inherited from interface org.xml.sax.Locator

Methods inherited from interface javax.xml.transform.SourceLocator

Constructor Detail

TraceExpression

Method Detail

setLineNumber

setColumnNumber

setConstructType

getConstructType

setNamespaceResolver

getNamespaceResolver

setSystemId

getSystemId

getLineNumber

setObjectName

getObjectName

setProperty

getProperty

getProperties

getColumnNumber

getInstructionInfo

getSystemId

getLineNumber

getColumnNumber