org.w3c.dom.xpath
Interface XPathResult
public interface XPathResult
The
XPathResult
interface represents the result of the
evaluation of an XPath 1.0 expression within the context of a particular
node. Since evaluation of an XPath expression can result in various
result types, this object makes it possible to discover and manipulate
the type and value of the result.
See also the
Document Object Model (DOM) Level 3 XPath Specification.
ANY_TYPE
public static final short ANY_TYPE
This code does not represent a specific type. An evaluation of an XPath
expression will never produce this type. If this type is requested,
then the evaluation returns whatever type naturally results from
evaluation of the expression.
If the natural result is a node set when ANY_TYPE
was
requested, then UNORDERED_NODE_ITERATOR_TYPE
is always
the resulting type. Any other representation of a node set must be
explicitly requested.
- 0
ANY_UNORDERED_NODE_TYPE
public static final short ANY_UNORDERED_NODE_TYPE
The result is a
node set as defined by [
XPath 1.0] and
will be accessed as a single node, which may be
null
if
the node set is empty. Document modification does not invalidate the
node, but may mean that the result node no longer corresponds to the
current document. This is a convenience that permits optimization
since the implementation can stop once any node in the resulting set
has been found.
If there is more than one node in the actual result, the single
node returned might not be the first in document order.
- 8
BOOLEAN_TYPE
public static final short BOOLEAN_TYPE
The result is a
boolean as defined by [
XPath 1.0].
Document modification does not invalidate the boolean, but may mean
that reevaluation would not yield the same boolean.
- 3
FIRST_ORDERED_NODE_TYPE
public static final short FIRST_ORDERED_NODE_TYPE
The result is a
node set as defined by [
XPath 1.0] and
will be accessed as a single node, which may be
null
if
the node set is empty. Document modification does not invalidate the
node, but may mean that the result node no longer corresponds to the
current document. This is a convenience that permits optimization
since the implementation can stop once the first node in document
order of the resulting set has been found.
If there are more than one node in the actual result, the single
node returned will be the first in document order.
- 9
NUMBER_TYPE
public static final short NUMBER_TYPE
The result is a
number as defined by [
XPath 1.0].
Document modification does not invalidate the number, but may mean
that reevaluation would not yield the same number.
- 1
ORDERED_NODE_ITERATOR_TYPE
public static final short ORDERED_NODE_ITERATOR_TYPE
The result is a node set as defined by [
XPath 1.0] that
will be accessed iteratively, which will produce document-ordered
nodes. Document modification invalidates the iteration.
- 5
ORDERED_NODE_SNAPSHOT_TYPE
public static final short ORDERED_NODE_SNAPSHOT_TYPE
The result is a
node set as defined by [
XPath 1.0] that
will be accessed as a snapshot list of nodes that will be in original
document order. Document modification does not invalidate the
snapshot but may mean that reevaluation would not yield the same
snapshot and nodes in the snapshot may have been altered, moved, or
removed from the document.
- 7
STRING_TYPE
public static final short STRING_TYPE
The result is a
string as defined by [
XPath 1.0].
Document modification does not invalidate the string, but may mean
that the string no longer corresponds to the current document.
- 2
UNORDERED_NODE_ITERATOR_TYPE
public static final short UNORDERED_NODE_ITERATOR_TYPE
The result is a
node set as defined by [
XPath 1.0] that
will be accessed iteratively, which may not produce nodes in a
particular order. Document modification invalidates the iteration.
This is the default type returned if the result is a node set and
ANY_TYPE
is requested.
- 4
UNORDERED_NODE_SNAPSHOT_TYPE
public static final short UNORDERED_NODE_SNAPSHOT_TYPE
The result is a
node set as defined by [
XPath 1.0] that
will be accessed as a snapshot list of nodes that may not be in a
particular order. Document modification does not invalidate the
snapshot but may mean that reevaluation would not yield the same
snapshot and nodes in the snapshot may have been altered, moved, or
removed from the document.
- 6
getBooleanValue
public boolean getBooleanValue()
throws XPathException
The value of this boolean result.
XPathException
- TYPE_ERR: raised if resultType
is not
BOOLEAN_TYPE
.
getInvalidIteratorState
public boolean getInvalidIteratorState()
Signifies that the iterator has become invalid. True if
resultType
is UNORDERED_NODE_ITERATOR_TYPE
or ORDERED_NODE_ITERATOR_TYPE
and the document has been
modified since this result was returned.
getNumberValue
public double getNumberValue()
throws XPathException
The value of this number result. If the native double type of the DOM
binding does not directly support the exact IEEE 754 result of the
XPath expression, then it is up to the definition of the binding to
specify how the XPath number is converted to the native binding
number.
XPathException
- TYPE_ERR: raised if resultType
is not
NUMBER_TYPE
.
getResultType
public short getResultType()
A code representing the type of this result, as defined by the type
constants.
getSingleNodeValue
public Node getSingleNodeValue()
throws XPathException
The value of this single node result, which may be null
.
XPathException
- TYPE_ERR: raised if resultType
is not
ANY_UNORDERED_NODE_TYPE
or
FIRST_ORDERED_NODE_TYPE
.
getSnapshotLength
public int getSnapshotLength()
throws XPathException
The number of nodes in the result snapshot. Valid values for
snapshotItem indices are 0
to
snapshotLength-1
inclusive.
XPathException
- TYPE_ERR: raised if resultType
is not
UNORDERED_NODE_SNAPSHOT_TYPE
or
ORDERED_NODE_SNAPSHOT_TYPE
.
getStringValue
public String getStringValue()
throws XPathException
The value of this string result.
XPathException
- TYPE_ERR: raised if resultType
is not
STRING_TYPE
.
iterateNext
public Node iterateNext()
throws XPathException,
DOMException
Iterates and returns the next node from the node set or
null
if there are no more nodes.
- Returns the next node.
XPathException
- TYPE_ERR: raised if resultType
is not
UNORDERED_NODE_ITERATOR_TYPE
or
ORDERED_NODE_ITERATOR_TYPE
.DOMException
- INVALID_STATE_ERR: The document has been mutated since the result was
returned.
snapshotItem
public Node snapshotItem(int index)
throws XPathException
Returns the index
th item in the snapshot collection. If
index
is greater than or equal to the number of nodes in
the list, this method returns null
. Unlike the iterator
result, the snapshot does not become invalid, but may not correspond
to the current document if it is mutated.
index
- Index into the snapshot collection.
- The node at the
index
th position in the
NodeList
, or null
if that is not a valid
index.
XPathException
- TYPE_ERR: raised if resultType
is not
UNORDERED_NODE_SNAPSHOT_TYPE
or
ORDERED_NODE_SNAPSHOT_TYPE
.