org.apache.xpath.operations
Class Variable
java.lang.Object
|
+--org.apache.xpath.Expression
|
+--org.apache.xpath.operations.Variable
- public class Variable
- extends Expression
The variable reference expression executer.
- See Also:
- Serialized Form
Method Summary |
XObject |
execute(XPathContext xctxt)
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. |
boolean |
isStableNumber()
Tell if this expression returns a stable number that will not change during
iterations within the expression. |
void |
setQName(QName qname)
Set the qualified name of the variable. |
Methods inherited from class org.apache.xpath.Expression |
asIterator,
asNode,
assertion,
bool,
canTraverseOutsideSubtree,
error,
execute,
execute,
executeCharsToContentHandler,
isNodesetExpr,
num,
setSourceLocator,
warn,
xstr |
Methods inherited from class java.lang.Object |
equals,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait |
Variable
public Variable()
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.
- 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).- Overrides:
- fixupVariables in class Expression
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.
execute
public XObject execute(XPathContext xctxt)
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.
- Parameters:
xctxt
- The runtime execution context.- Returns:
- The evaluated variable, or an empty nodeset if not found.
- Throws:
- javax.xml.transform.TransformerException -
- Overrides:
- execute in class Expression
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.
- Returns:
- true if the expression represents a stable number.
- Overrides:
- isStableNumber in class Expression
Copyright © 2001 Apache XML Project. All Rights Reserved.