net.sf.saxon.sxpath
Class XPathVariable

java.lang.Object
  net.sf.saxon.sxpath.XPathVariable

All Implemented Interfaces:

Serializable, Binding, VariableDeclaration

public final class XPathVariable
extends Object
implements VariableDeclaration, Binding, Serializable

An object representing an XPath variable for use in the standalone XPath API. The object can only be created by calling the declareVariable method of class StandaloneContext. Note that once declared, this object is thread-safe: it does not hold the actual variable value, which means it can be used with any number of evaluations of a given XPath expression, in series or in parallel.

See Also:

Serialized Form

Method Summary

ValueRepresentation	evaluateVariable(XPathContext context) Get the value of the variable.
int	getLocalSlotNumber() If this is a local variable held on the local stack frame, return the corresponding slot number.
int	getNameCode() Establish the nameCode of the name of this variable.
String	getVariableName() Get the name of the variable.
QNameValue	getVariableQName() Get the name of the variable as a QNameValue.
boolean	isAssignable() Test whether it is permitted to assign to the variable using the saxon:assign extension element.
boolean	isGlobal() Indicate whether the binding is local or global.
void	registerReference(BindingReference ref) Method called by the XPath expression parser to register a reference to this variable.
void	setSlotNumber(int slotNumber) Set the slot number allocated to this variable

Methods inherited from class java.lang.Object

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

Method Detail

isGlobal

public boolean isGlobal()

Indicate whether the binding is local or global. A global binding is one that has a fixed value for the life of a query or transformation; any other binding is local.

Specified by:

isGlobal in interface Binding

isAssignable

public final boolean isAssignable()

Test whether it is permitted to assign to the variable using the saxon:assign extension element. This will only be for an XSLT global variable where the extra attribute saxon:assignable="yes" is present.

Specified by:

isAssignable in interface Binding

setSlotNumber

public void setSlotNumber(int slotNumber)

Set the slot number allocated to this variable

Parameters:

slotNumber -

getLocalSlotNumber

public int getLocalSlotNumber()

If this is a local variable held on the local stack frame, return the corresponding slot number. In other cases, return -1.

Specified by:

getLocalSlotNumber in interface Binding

getVariableQName

public QNameValue getVariableQName()

Get the name of the variable as a QNameValue.

Returns:

the name of the variable, as a QNameValue

getVariableName

public String getVariableName()

Get the name of the variable. Used for diagnostic purposes only.

Specified by:

getVariableName in interface VariableDeclaration

Returns:

the name of the variable, as a string (containing the raw QName)

getNameCode

public int getNameCode()

Establish the nameCode of the name of this variable.

Specified by:

getNameCode in interface VariableDeclaration

Returns:

the nameCode

registerReference

public void registerReference(BindingReference ref)

Method called by the XPath expression parser to register a reference to this variable. This method should not be called by users of the API.

Specified by:

registerReference in interface VariableDeclaration

evaluateVariable

public ValueRepresentation evaluateVariable(XPathContext context)

Get the value of the variable. This method is used by the XPath execution engine to retrieve the value. Note that the value is not held within the variable itself, but within the dunamic context.

Specified by:

evaluateVariable in interface Binding

Parameters:

context - The dynamic evaluation context

Returns:

The value of the variable