net.sf.saxon.tree.iter
Class NamespaceIterator

java.lang.Object
  extended by net.sf.saxon.tree.iter.NamespaceIterator
All Implemented Interfaces:
SequenceIterator, AxisIterator, UnfailingIterator

public class NamespaceIterator
extends Object
implements AxisIterator

This class provides an implementation of the namespace axis over any implementation of the data model. It relies on element nodes to implement the method NodeInfo.getDeclaredNamespaces(int[])


Nested Class Summary
static class NamespaceIterator.NamespaceNodeImpl
          Inner class: a model-independent representation of a namespace node
 
Field Summary
 
Fields inherited from interface net.sf.saxon.om.SequenceIterator
GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD
 
Method Summary
 void advance()
          Get the next item in the sequence.
 Value atomize()
          Return the atomized value of the current node.
 void close()
          Close the iterator.
 Item current()
          Get the current item in the sequence.
 SequenceIterator getAnother()
          Get another iterator over the same sequence of items, positioned at the start of the sequence
static int[] getInScopeNamespaceCodes(NodeInfo element)
          Get a list of in-scope namespace codes.
 int getProperties()
          Get properties of this iterator, as a bit-significant integer.
 CharSequence getStringValue()
          Return the string value of the current node.
 AxisIterator iterateAxis(byte axis, NodeTest test)
          Return an iterator over an axis, starting at the current node.
static AxisIterator makeIterator(NodeInfo element, NodeTest test)
          Factory method to create an iterator over the in-scope namespace nodes
 boolean moveNext()
          Move to the next node, without returning it.
 Item next()
          Get the next item in the sequence.
 int position()
          Get the current position
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

makeIterator

public static AxisIterator makeIterator(NodeInfo element,
                                        NodeTest test)
Factory method to create an iterator over the in-scope namespace nodes

Parameters:
element - the node whose namespaces are required
test - used to filter the returned nodes
Returns:
an iterator over the namespace nodes that satisfy the test

advance

public void advance()
Get the next item in the sequence.


moveNext

public boolean moveNext()
Move to the next node, without returning it. Returns true if there is a next node, false if the end of the sequence has been reached. After calling this method, the current node may be retrieved using the current() function.

Specified by:
moveNext in interface AxisIterator

next

public Item next()
Get the next item in the sequence.

Specified by:
next in interface SequenceIterator
Specified by:
next in interface UnfailingIterator
Returns:
the next Item. If there are no more nodes, return null.

current

public Item current()
Get the current item in the sequence.

Specified by:
current in interface SequenceIterator
Specified by:
current in interface UnfailingIterator
Returns:
the current item, that is, the item most recently returned by next()

position

public int position()
Get the current position

Specified by:
position in interface SequenceIterator
Specified by:
position in interface UnfailingIterator
Returns:
the position of the current item (the item most recently returned by next()), starting at 1 for the first node

close

public void close()
Description copied from interface: SequenceIterator
Close the iterator. This indicates to the supplier of the data that the client does not require any more items to be delivered by the iterator. This may enable the supplier to release resources. After calling close(), no further calls on the iterator should be made; if further calls are made, the effect of such calls is undefined.

(Currently, closing an iterator is important only when the data is being "pushed" in another thread. Closing the iterator terminates that thread and means that it needs to do no additional work. Indeed, failing to close the iterator may cause the push thread to hang waiting for the buffer to be emptied.)

Specified by:
close in interface SequenceIterator

iterateAxis

public AxisIterator iterateAxis(byte axis,
                                NodeTest test)
Return an iterator over an axis, starting at the current node.

Specified by:
iterateAxis in interface AxisIterator
Parameters:
axis - the axis to iterate over, using a constant such as Axis.CHILD
test - a predicate to apply to the nodes before returning them.
Throws:
NullPointerException - if there is no current node

atomize

public Value atomize()
              throws XPathException
Return the atomized value of the current node.

Specified by:
atomize in interface AxisIterator
Returns:
the atomized value.
Throws:
NullPointerException - if there is no current node
XPathException

getStringValue

public CharSequence getStringValue()
Return the string value of the current node.

Specified by:
getStringValue in interface AxisIterator
Returns:
the string value, as an instance of CharSequence.
Throws:
NullPointerException - if there is no current node

getAnother

public SequenceIterator getAnother()
Get another iterator over the same sequence of items, positioned at the start of the sequence

Specified by:
getAnother in interface SequenceIterator
Specified by:
getAnother in interface UnfailingIterator
Returns:
a new iterator over the same sequence

getProperties

public int getProperties()
Get properties of this iterator, as a bit-significant integer.

Specified by:
getProperties in interface SequenceIterator
Returns:
the properties of this iterator. This will be some combination of properties such as SequenceIterator.GROUNDED, SequenceIterator.LAST_POSITION_FINDER, and SequenceIterator.LOOKAHEAD. It is always acceptable to return the value zero, indicating that there are no known special properties. It is acceptable for the properties of the iterator to change depending on its state.

getInScopeNamespaceCodes

public static int[] getInScopeNamespaceCodes(NodeInfo element)
Get a list of in-scope namespace codes. If an array of namespace codes is needed, without actually constructing the namespace nodes, this factory method can be used directly. The result is an array of integers, each containing a prefix code in the top half and a uri code in the bottom half. Note that calling this method is destructive: the iterator is consumed and cannot be used again.

Parameters:
element - the element whose nodes are required
Returns:
the list of in scope namespaces


Copyright (c) 2004-2010 Saxonica Limited. All rights reserved.