Package net.sf.saxon.trans
Class Variable
- java.lang.Object
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- net.sf.saxon.trans.Variable
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- All Implemented Interfaces:
java.io.Serializable
,Binding
,VariableDeclaration
public final class Variable extends java.lang.Object implements VariableDeclaration, Binding, java.io.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.- See Also:
- Serialized Form
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description 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.java.lang.String
getVariableName()
Get the name of the variable.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.static Variable
make(QNameValue name, Configuration config)
Factory method, for use by the declareVariable method of class StandaloneContextvoid
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 variablevoid
setUseStack(boolean useStack)
Indicate that values of variables are to be found on the stack, not in the Variable object itselfvoid
setValue(java.lang.Object value)
Assign a value to the variable.void
setXPathValue(ValueRepresentation value)
Assign a value to the variable.
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Method Detail
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make
public static Variable make(QNameValue name, Configuration config)
Factory method, for use by the declareVariable method of class StandaloneContext
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setUseStack
public void setUseStack(boolean useStack)
Indicate that values of variables are to be found on the stack, not in the Variable object itself
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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.
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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 interfaceBinding
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setSlotNumber
public void setSlotNumber(int slotNumber)
Set the slot number allocated to this variable- Parameters:
slotNumber
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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 interfaceBinding
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getVariableName
public java.lang.String getVariableName()
Get the name of the variable. Used for diagnostic purposes only.- Specified by:
getVariableName
in interfaceVariableDeclaration
- Returns:
- the name of the variable, as a string (containing the raw QName)
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getNameCode
public int getNameCode()
Establish the nameCode of the name of this variable.- Specified by:
getNameCode
in interfaceVariableDeclaration
- Returns:
- the nameCode
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setValue
public void setValue(java.lang.Object value) throws XPathException
Assign a value to the variable. This value may be changed between successive evaluations of a compiled XPath expression that references the variable. If this method is called, the value will be set directly within the Variable object. This is only workable if compilation and execution happen in the same thread. The preferred approach is to set the variable in the stack frame of the XPathContext object.- Parameters:
value
- the value of the variable, as a Java object. This is converted to the "best fit" XPath data type.- Throws:
XPathException
- if the Java value cannot be converted to an XPath type
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setXPathValue
public void setXPathValue(ValueRepresentation value)
Assign a value to the variable. This value may be changed between successive evaluations of a compiled XPath expression that references the variable. If this method is called, the value will be set directly within the Variable object. This is only workable if compilation and execution happen in the same thread. The preferred approach is to set the variable in the stack frame of the XPathContext object.- Parameters:
value
- the value of the variable, which must be an instance of a class representing a value in the XPath model.
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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 interfaceVariableDeclaration
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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.- Specified by:
evaluateVariable
in interfaceBinding
- Parameters:
context
- The dynamic evaluation context- Returns:
- The value of the variable
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