Package org.apache.xpath.operations
Class Variable
- java.lang.Object
-
- org.apache.xpath.Expression
-
- org.apache.xpath.operations.Variable
-
- All Implemented Interfaces:
java.io.Serializable
,javax.xml.transform.SourceLocator
,PathComponent
,ExpressionNode
,XPathVisitable
- Direct Known Subclasses:
VariableSafeAbsRef
public class Variable extends Expression implements PathComponent
The variable reference expression executer.- See Also:
- Serialized Form
-
-
Constructor Summary
Constructors Constructor Description Variable()
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
callVisitors(ExpressionOwner owner, XPathVisitor visitor)
This will traverse the heararchy, calling the visitor for each member.boolean
deepEquals(Expression expr)
Compare this object with another object and see if they are equal, include the sub heararchy.XObject
execute(XPathContext xctxt)
Execute an expression in the XPath runtime context, and return the result of the expression.XObject
execute(XPathContext xctxt, boolean destructiveOK)
Dereference the variable, and return the reference value.void
fixupVariables(java.util.Vector vars, int globalsSize)
This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.int
getAnalysisBits()
Get the analysis bits for this walker, as defined in the WalkerFactory.ElemVariable
getElemVariable()
Get the XSLT ElemVariable that this sub-expression references.boolean
getGlobal()
Set the index for the variable into the stack.int
getIndex()
Set the index for the variable into the stack.QName
getQName()
Get the qualified name of the variable.boolean
isPsuedoVarRef()
Tell if this is a psuedo variable reference, declared by Xalan instead of by the user.boolean
isStableNumber()
Tell if this expression returns a stable number that will not change during iterations within the expression.void
setIndex(int index)
Set the index for the variable into the stack.void
setIsGlobal(boolean isGlobal)
Set whether or not this is a global reference.void
setQName(QName qname)
Set the qualified name of the variable.-
Methods inherited from class org.apache.xpath.Expression
asIterator, asIteratorRaw, asNode, assertion, bool, canTraverseOutsideSubtree, error, execute, execute, executeCharsToContentHandler, exprAddChild, exprGetChild, exprGetNumChildren, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isNodesetExpr, num, warn, xstr
-
-
-
-
Method Detail
-
setIndex
public void setIndex(int index)
Set the index for the variable into the stack. For advanced use only. You must know what you are doing to use this.- Parameters:
index
- a global or local index.
-
getIndex
public int getIndex()
Set the index for the variable into the stack. For advanced use only.- Returns:
- index a global or local index.
-
setIsGlobal
public void setIsGlobal(boolean isGlobal)
Set whether or not this is a global reference. For advanced use only.- Parameters:
isGlobal
- true if this should be a global variable reference.
-
getGlobal
public boolean getGlobal()
Set the index for the variable into the stack. For advanced use only.- Returns:
- true if this should be a global variable reference.
-
fixupVariables
public void fixupVariables(java.util.Vector vars, int globalsSize)
This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.- Specified by:
fixupVariables
in classExpression
- Parameters:
vars
- List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame).
-
setQName
public void setQName(QName qname)
Set the qualified name of the variable.- Parameters:
qname
- Must be a non-null reference to a qualified name.
-
getQName
public QName getQName()
Get the qualified name of the variable.- Returns:
- A non-null reference to a qualified name.
-
execute
public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
Execute an expression in the XPath runtime context, and return the result of the expression.- Specified by:
execute
in classExpression
- Parameters:
xctxt
- The XPath runtime context.- Returns:
- The result of the expression in the form of a
XObject
. - Throws:
javax.xml.transform.TransformerException
- if a runtime exception occurs.
-
execute
public XObject execute(XPathContext xctxt, boolean destructiveOK) throws javax.xml.transform.TransformerException
Dereference the variable, and return the reference value. Note that lazy evaluation will occur. If a variable within scope is not found, a warning will be sent to the error listener, and an empty nodeset will be returned.- Overrides:
execute
in classExpression
- Parameters:
xctxt
- The runtime execution context.destructiveOK
- true if a "safe" object doesn't need to be returned.- Returns:
- The evaluated variable, or an empty nodeset if not found.
- Throws:
javax.xml.transform.TransformerException
-
getElemVariable
public ElemVariable getElemVariable()
Get the XSLT ElemVariable that this sub-expression references. In order for this to work, the SourceLocator must be the owning ElemTemplateElement.- Returns:
- The dereference to the ElemVariable, or null if not found.
-
isStableNumber
public boolean isStableNumber()
Tell if this expression returns a stable number that will not change during iterations within the expression. This is used to determine if a proximity position predicate can indicate that no more searching has to occur.- Overrides:
isStableNumber
in classExpression
- Returns:
- true if the expression represents a stable number.
-
getAnalysisBits
public int getAnalysisBits()
Get the analysis bits for this walker, as defined in the WalkerFactory.- Specified by:
getAnalysisBits
in interfacePathComponent
- Returns:
- One of WalkerFactory#BIT_DESCENDANT, etc.
-
callVisitors
public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
Description copied from interface:XPathVisitable
This will traverse the heararchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.- Specified by:
callVisitors
in interfaceXPathVisitable
- Parameters:
owner
- The owner of the visitor, where that path may be rewritten if needed.visitor
- The visitor whose appropriate method will be called.- See Also:
XPathVisitable.callVisitors(ExpressionOwner, XPathVisitor)
-
deepEquals
public boolean deepEquals(Expression expr)
Description copied from class:Expression
Compare this object with another object and see if they are equal, include the sub heararchy.- Specified by:
deepEquals
in classExpression
- Parameters:
expr
- Another expression object.- Returns:
- true if this objects class and the expr object's class are the same, and the data contained within both objects are considered equal.
- See Also:
Expression.deepEquals(Expression)
-
isPsuedoVarRef
public boolean isPsuedoVarRef()
Tell if this is a psuedo variable reference, declared by Xalan instead of by the user.
-
-