XPathVariable

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

All Implemented Interfaces:

Binding, LocalBinding
```
public final class XPathVariable
extends java.lang.Object
implements LocalBinding
```
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 IndependentContext. 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.

A variable can be given a value by calling XPathDynamicContext.setVariable(XPathVariable, net.sf.saxon.om.Sequence). Note that the value of the variable is not held in the XPathVariable object, but in the XPathDynamicContext, which means that the XPathVariable itself can be used in multiple threads.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addReference(VariableReference ref, boolean isLoopingReference)` Method called by the XPath expression parser to register a reference to this variable.
`Sequence`	`evaluateVariable(XPathContext context)` Get the value of the variable.
`Sequence`	`getDefaultValue()` Get the default value of the variable
`IntegerValue[]`	`getIntegerBoundsForVariable()` If the variable is bound to an integer, get the minimum and maximum possible values.
`int`	`getLocalSlotNumber()` If this is a local variable held on the local stack frame, return the corresponding slot number.
`SequenceType`	`getRequiredType()` Get the required type of this variable.
`StructuredQName`	`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()` Ask whether the binding is local or global.
`boolean`	`isIndexedVariable()` Ask whether the binding is to be indexed
`protected static XPathVariable`	`make(StructuredQName name)` Factory method, for use by the declareVariable method of class IndependentContext
`void`	`setDefaultValue(Sequence defaultValue)` Set a default value for the variable, to be used if no specific value is supplied when the expression is evaluated
`void`	`setIndexedVariable()` Say that the bound value has the potential to be indexed
`void`	`setRequiredType(SequenceType requiredType)` Set the required type of this variable.
`void`	`setSlotNumber(int slotNumber)` Set the slot number allocated to this variable.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - make
```
protected static XPathVariable make(StructuredQName name)
```
    Factory method, for use by the declareVariable method of class IndependentContext
    
    Parameters:
    
    name - the name of the variable to create
    
    Returns:
    
    the constructed XPathVariable
  - isGlobal
```
public boolean isGlobal()
```
    Ask 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. An XPath variable is treated as a local variable (largely because it is held on the stack frame)
    
    Specified by:
    
    isGlobal in interface Binding
    
    Returns:
    
    false (always)
  - 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
    
    Returns:
    
    false (always)
  - setRequiredType
```
public void setRequiredType(SequenceType requiredType)
```
    Set the required type of this variable. If no required type is specified, the type item()* is assumed.
    
    Parameters:
    
    requiredType - the required type
  - getRequiredType
```
public SequenceType getRequiredType()
```
    Get the required type of this variable. If no required type has been specified, the type item()* is returned.
    
    Specified by:
    
    getRequiredType in interface Binding
    
    Returns:
    
    the required type of the variable
  - getIntegerBoundsForVariable
```
public IntegerValue[] getIntegerBoundsForVariable()
```
    If the variable is bound to an integer, get the minimum and maximum possible values. Return null if unknown or not applicable
    
    Specified by:
    
    getIntegerBoundsForVariable in interface Binding
    
    Returns:
    
    a pair of integers containing the minimum and maximum values for the integer value; or null if the value is not an integer or the range is unknown
  - setSlotNumber
```
public void setSlotNumber(int slotNumber)
```
    Set the slot number allocated to this variable. This method is for internal use.
    
    Parameters:
    
    slotNumber - the slot number to be allocated
  - 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 LocalBinding
    
    Returns:
    
    the slot number on the local stack frame
  - getVariableQName
```
public StructuredQName getVariableQName()
```
    Get the name of the variable as a QNameValue.
    
    Specified by:
    
    getVariableQName in interface Binding
    
    Returns:
    
    the name of the variable, as a QNameValue
  - addReference
```
public void addReference(VariableReference ref,
                         boolean isLoopingReference)
```
    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:
    
    addReference in interface Binding
    
    Parameters:
    
    ref - the variable reference
    
    isLoopingReference - - true if the reference occurs within a loop, such as the predicate of a filter expression
  - setDefaultValue
```
public void setDefaultValue(Sequence defaultValue)
```
    Set a default value for the variable, to be used if no specific value is supplied when the expression is evaluated
    
    Parameters:
    
    defaultValue - the default value for the variable
  - getDefaultValue
```
public Sequence getDefaultValue()
```
    Get the default value of the variable
    
    Returns:
    
    the default value if one has been registered, or null otherwise
  - evaluateVariable
```
public Sequence 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 dynamic context.
    
    Specified by:
    
    evaluateVariable in interface Binding
    
    Parameters:
    
    context - The dynamic evaluation context
    
    Returns:
    
    The value of the variable
  - setIndexedVariable
```
public void setIndexedVariable()
```
    Say that the bound value has the potential to be indexed
    
    Specified by:
    
    setIndexedVariable in interface LocalBinding
  - isIndexedVariable
```
public boolean isIndexedVariable()
```
    Ask whether the binding is to be indexed
    
    Specified by:
    
    isIndexedVariable in interface LocalBinding
    
    Returns:
    
    true if the variable value can be indexed

Class XPathVariable

Method Summary

Methods inherited from class java.lang.Object

Method Detail

make

isGlobal

isAssignable

setRequiredType

getRequiredType

getIntegerBoundsForVariable

setSlotNumber

getLocalSlotNumber

getVariableQName

addReference

setDefaultValue

getDefaultValue

evaluateVariable

setIndexedVariable

isIndexedVariable