org.apache.commons.jxpath.ri.axes
Class RootContext

java.lang.Object
  extended by org.apache.commons.jxpath.ri.EvalContext
      extended by org.apache.commons.jxpath.ri.axes.RootContext
All Implemented Interfaces:
java.util.Iterator, ExpressionContext

public class RootContext
extends EvalContext

EvalContext that is used to hold the root node for the path traversal.

Version:
$Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
Author:
Dmitri Plotnikov

Field Summary
static java.lang.Object UNKNOWN_VALUE
           
 
Fields inherited from class org.apache.commons.jxpath.ri.EvalContext
parentContext, position, rootContext
 
Constructor Summary
RootContext(JXPathContextReferenceImpl jxpathContext, NodePointer pointer)
          Create a new RootContext.
 
Method Summary
 EvalContext getAbsoluteRootContext()
          Get absolute root context
 EvalContext getConstantContext(java.lang.Object constant)
          Get a context that points to the specified object.
 NodePointer getCurrentNodePointer()
          Returns the current context node.
 int getCurrentPosition()
          Get the current position.
 Function getFunction(QName functionName, java.lang.Object[] parameters)
          Get the specified function from the context.
 JXPathContext getJXPathContext()
          Get the JXPathContext in which this function is being evaluated.
 java.lang.Object getRegisteredValue(int id)
          Get a registered value.
 RootContext getRootContext()
          Returns the root context of the path, which provides easy access to variables and functions.
 java.lang.Object getValue()
          Typically returns the NodeSet by calling getNodeSet(), but will be overridden for contexts that more naturally produce individual values, e.g.
 EvalContext getVariableContext(QName variableName)
          Get variable context.
 boolean nextNode()
          Returns true if there is another object in the current set.
 boolean nextSet()
          Returns true if there is another sets of objects to interate over.
 boolean setPosition(int position)
          Moves the current position to the specified index.
 int setRegisteredValue(java.lang.Object value)
          Set the next registered value.
 java.lang.String toString()
           
 
Methods inherited from class org.apache.commons.jxpath.ri.EvalContext
getContextNodeList, getContextNodePointer, getDocumentOrder, getNodeSet, getPosition, getSingleNodePointer, hasNext, isChildOrderingRequired, next, remove, reset, sortPointers
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

UNKNOWN_VALUE

public static final java.lang.Object UNKNOWN_VALUE
Constructor Detail

RootContext

public RootContext(JXPathContextReferenceImpl jxpathContext,
                   NodePointer pointer)
Create a new RootContext.

Parameters:
jxpathContext - context
pointer - pointer
Method Detail

getJXPathContext

public JXPathContext getJXPathContext()
Description copied from interface: ExpressionContext
Get the JXPathContext in which this function is being evaluated.

Specified by:
getJXPathContext in interface ExpressionContext
Overrides:
getJXPathContext in class EvalContext
Returns:
A list representing the current context nodes.

getRootContext

public RootContext getRootContext()
Description copied from class: EvalContext
Returns the root context of the path, which provides easy access to variables and functions.

Overrides:
getRootContext in class EvalContext
Returns:
RootContext

getAbsoluteRootContext

public EvalContext getAbsoluteRootContext()
Get absolute root context

Returns:
EvalContext

getCurrentNodePointer

public NodePointer getCurrentNodePointer()
Description copied from class: EvalContext
Returns the current context node. Undefined before the beginning of the iteration.

Specified by:
getCurrentNodePointer in class EvalContext
Returns:
NodePoiner

getValue

public java.lang.Object getValue()
Description copied from class: EvalContext
Typically returns the NodeSet by calling getNodeSet(), but will be overridden for contexts that more naturally produce individual values, e.g. VariableContext

Overrides:
getValue in class EvalContext
Returns:
Object

getCurrentPosition

public int getCurrentPosition()
Description copied from class: EvalContext
Get the current position.

Overrides:
getCurrentPosition in class EvalContext
Returns:
int position.

nextNode

public boolean nextNode()
Description copied from class: EvalContext
Returns true if there is another object in the current set. Switches the current position and node to the next object.

Specified by:
nextNode in class EvalContext
Returns:
boolean

nextSet

public boolean nextSet()
Description copied from class: EvalContext
Returns true if there is another sets of objects to interate over. Resets the current position and node.

Overrides:
nextSet in class EvalContext
Returns:
boolean

setPosition

public boolean setPosition(int position)
Description copied from class: EvalContext
Moves the current position to the specified index. Used with integer predicates to quickly get to the n'th element of the node set. Returns false if the position is out of the node set range. You can call it with 0 as the position argument to restart the iteration.

Overrides:
setPosition in class EvalContext
Parameters:
position - to set
Returns:
boolean

getConstantContext

public EvalContext getConstantContext(java.lang.Object constant)
Get a context that points to the specified object.

Parameters:
constant - object
Returns:
EvalContext

getVariableContext

public EvalContext getVariableContext(QName variableName)
Get variable context.

Parameters:
variableName - variable name
Returns:
EvalContext

getFunction

public Function getFunction(QName functionName,
                            java.lang.Object[] parameters)
Get the specified function from the context.

Parameters:
functionName - QName
parameters - Object[]
Returns:
Function

getRegisteredValue

public java.lang.Object getRegisteredValue(int id)
Get a registered value.

Parameters:
id - int
Returns:
Object

setRegisteredValue

public int setRegisteredValue(java.lang.Object value)
Set the next registered value.

Parameters:
value - Object
Returns:
the id that can reclaim value.

toString

public java.lang.String toString()
Overrides:
toString in class EvalContext


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