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.
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Field Summary
Modifier and TypeFieldDescriptionstatic final short
This code does not represent a specific type.static final short
The result is a node set as defined by and will be accessed as a single node, which may benull
if the node set is empty.static final short
The result is a boolean as defined by .static final short
The result is a node set as defined by and will be accessed as a single node, which may benull
if the node set is empty.static final short
The result is a number as defined by .static final short
The result is a node set as defined by that will be accessed iteratively, which will produce document-ordered nodes.static final short
The result is a node set as defined by that will be accessed as a snapshot list of nodes that will be in original document order.static final short
The result is a string as defined by .static final short
The result is a node set as defined by that will be accessed iteratively, which may not produce nodes in a particular order.static final short
The result is a node set as defined by that will be accessed as a snapshot list of nodes that may not be in a particular order. -
Method Summary
Modifier and TypeMethodDescriptionboolean
The value of this boolean result.boolean
Signifies that the iterator has become invalid.double
The value of this number result.short
A code representing the type of this result, as defined by the type constants.The value of this single node result, which may benull
.int
The number of nodes in the result snapshot.The value of this string result.Iterates and returns the next node from the node set ornull
if there are no more nodes.snapshotItem
(int index) Returns theindex
th item in the snapshot collection.
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Field Details
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ANY_TYPE
static final short ANY_TYPEThis 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 whenANY_TYPE
was requested, thenUNORDERED_NODE_ITERATOR_TYPE
is always the resulting type. Any other representation of a node set must be explicitly requested.- See Also:
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NUMBER_TYPE
static final short NUMBER_TYPEThe result is a number as defined by . Document modification does not invalidate the number, but may mean that reevaluation would not yield the same number.- See Also:
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STRING_TYPE
static final short STRING_TYPEThe result is a string as defined by . Document modification does not invalidate the string, but may mean that the string no longer corresponds to the current document.- See Also:
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BOOLEAN_TYPE
static final short BOOLEAN_TYPEThe result is a boolean as defined by . Document modification does not invalidate the boolean, but may mean that reevaluation would not yield the same boolean.- See Also:
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UNORDERED_NODE_ITERATOR_TYPE
static final short UNORDERED_NODE_ITERATOR_TYPEThe result is a node set as defined by 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 andANY_TYPE
is requested.- See Also:
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ORDERED_NODE_ITERATOR_TYPE
static final short ORDERED_NODE_ITERATOR_TYPEThe result is a node set as defined by that will be accessed iteratively, which will produce document-ordered nodes. Document modification invalidates the iteration.- See Also:
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UNORDERED_NODE_SNAPSHOT_TYPE
static final short UNORDERED_NODE_SNAPSHOT_TYPEThe result is a node set as defined by 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.- See Also:
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ORDERED_NODE_SNAPSHOT_TYPE
static final short ORDERED_NODE_SNAPSHOT_TYPEThe result is a node set as defined by 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.- See Also:
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ANY_UNORDERED_NODE_TYPE
static final short ANY_UNORDERED_NODE_TYPEThe result is a node set as defined by and will be accessed as a single node, which may benull
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 in the resulting set has been found.
If there are more than one node in the actual result, the single node returned might not be the first in document order.- See Also:
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FIRST_ORDERED_NODE_TYPE
static final short FIRST_ORDERED_NODE_TYPEThe result is a node set as defined by and will be accessed as a single node, which may benull
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.- See Also:
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Method Details
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getResultType
short getResultType()A code representing the type of this result, as defined by the type constants. -
getNumberValue
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 binding to specify how the XPath number is converted to the native binding number.- Throws:
XPathException
- TYPE_ERR: raised ifresultType
is notNUMBER_TYPE
.
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getStringValue
The value of this string result.- Throws:
XPathException
- TYPE_ERR: raised ifresultType
is notSTRING_TYPE
.
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getBooleanValue
The value of this boolean result.- Throws:
XPathException
- TYPE_ERR: raised ifresultType
is notBOOLEAN_TYPE
.
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getSingleNodeValue
The value of this single node result, which may benull
.- Throws:
XPathException
- TYPE_ERR: raised ifresultType
is notANY_UNORDERED_NODE_TYPE
orFIRST_ORDERED_NODE_TYPE
.
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getInvalidIteratorState
boolean getInvalidIteratorState()Signifies that the iterator has become invalid. True ifresultType
isUNORDERED_NODE_ITERATOR_TYPE
orORDERED_NODE_ITERATOR_TYPE
and the document has been modified since this result was returned. -
getSnapshotLength
The number of nodes in the result snapshot. Valid values for snapshotItem indices are0
tosnapshotLength-1
inclusive.- Throws:
XPathException
- TYPE_ERR: raised ifresultType
is notUNORDERED_NODE_SNAPSHOT_TYPE
orORDERED_NODE_SNAPSHOT_TYPE
.
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iterateNext
Iterates and returns the next node from the node set ornull
if there are no more nodes.- Returns:
- Returns the next node.
- Throws:
XPathException
- TYPE_ERR: raised ifresultType
is notUNORDERED_NODE_ITERATOR_TYPE
orORDERED_NODE_ITERATOR_TYPE
.DOMException
- INVALID_STATE_ERR: The document has been mutated since the result was returned.
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snapshotItem
Returns theindex
th item in the snapshot collection. Ifindex
is greater than or equal to the number of nodes in the list, this method returnsnull
. Unlike the iterator result, the snapshot does not become invalid, but may not correspond to the current document if it is mutated.- Parameters:
index
- Index into the snapshot collection.- Returns:
- The node at the
index
th position in theNodeList
, ornull
if that is not a valid index. - Throws:
XPathException
- TYPE_ERR: raised ifresultType
is notUNORDERED_NODE_SNAPSHOT_TYPE
orORDERED_NODE_SNAPSHOT_TYPE
.
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