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DTMAxisTraverser.java API Doc Java SE 5 API 4443 Fri Aug 26 14:56:00 BST 2005 com.sun.org.apache.xml.internal.dtm

DTMAxisTraverser

java.lang.Object

public abstract class DTMAxisTraverser extends Object

A class that implements traverses DTMAxisTraverser interface can traverse a set of nodes, usually as defined by an XPath axis. It is different from an iterator, because it does not need to hold state, and, in fact, must not hold any iteration-based state. It is meant to be implemented as an inner class of a DTM, and returned by the getAxisTraverser(final int axis) function.

A DTMAxisTraverser can probably not traverse a reverse axis in document order.

Typical usage:


for(int nodeHandle=myTraverser.first(myContext);
nodeHandle!=DTM.NULL;
nodeHandle=myTraverser.next(myContext,nodeHandle))
{ ... processing for node indicated by nodeHandle goes here ... }

author: Scott Boag

Fields Summary
Constructors Summary
Methods Summary
public int first(int context)
By the nature of the stateless traversal, the context node can not be returned or the iteration will go into an infinate loop. So to traverse an axis, the first function must be used to get the first node.
This method needs to be overloaded only by those axis that process the self node. <\p>
param
context The context node of this traversal. This is the point that the traversal starts from.
return
the first node in the traversal.
return next(context, context);
public int first(int context, int extendedTypeID)
By the nature of the stateless traversal, the context node can not be returned or the iteration will go into an infinate loop. So to traverse an axis, the first function must be used to get the first node.
This method needs to be overloaded only by those axis that process the self node. <\p>
param
context The context node of this traversal. This is the point of origin for the traversal -- its "root node" or starting point.
param
extendedTypeID The extended type ID that must match.
return
the first node in the traversal.
return next(context, context, extendedTypeID);
public abstract int next(int context, int current)
Traverse to the next node after the current node.
param
context The context node of this traversal. This is the point of origin for the traversal -- its "root node" or starting point.
param
current The current node of the traversal. This is the last known location in the traversal, typically the node-handle returned by the previous traversal step. For the first traversal step, context should be set equal to current. Note that in order to test whether context is in the set, you must use the first() method instead.
return
the next node in the iteration, or DTM.NULL.
see
first(int)
public abstract int next(int context, int current, int extendedTypeID)
Traverse to the next node after the current node that is matched by the extended type ID.
param
context The context node of this traversal. This is the point of origin for the traversal -- its "root node" or starting point.
param
current The current node of the traversal. This is the last known location in the traversal, typically the node-handle returned by the previous traversal step. For the first traversal step, context should be set equal to current. Note that in order to test whether context is in the set, you must use the first() method instead.
param
extendedTypeID The extended type ID that must match.
return
the next node in the iteration, or DTM.NULL.
see
first(int,int)