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.
*/
public interface XPathResult {
// XPathResultType
/**
* 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.
*/
public static final short ANY_TYPE = 0;
/**
* 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.
*/
public static final short NUMBER_TYPE = 1;
/**
* 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.
*/
public static final short STRING_TYPE = 2;
/**
* 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.
*/
public static final short BOOLEAN_TYPE = 3;
/**
* 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.
*/
public static final short UNORDERED_NODE_ITERATOR_TYPE = 4;
/**
* 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.
*/
public static final short ORDERED_NODE_ITERATOR_TYPE = 5;
/**
* 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.
*/
public static final short UNORDERED_NODE_SNAPSHOT_TYPE = 6;
/**
* 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.
*/
public static final short ORDERED_NODE_SNAPSHOT_TYPE = 7;
/**
* The result is a node set as defined by [XPath 1.0] and
* will be accessed as a single node, which may be nullif
* 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.
*/
public static final short ANY_UNORDERED_NODE_TYPE = 8;
/**
* 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.
*/
public static final short FIRST_ORDERED_NODE_TYPE = 9;
/**
* A code representing the type of this result, as defined by the type
* constants.
*/
public short getResultType();
/**
* 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.
* @exception XPathException
* TYPE_ERR: raised if resultType is not
* NUMBER_TYPE.
*/
public double getNumberValue()
throws XPathException;
/**
* The value of this string result.
* @exception XPathException
* TYPE_ERR: raised if resultType is not
* STRING_TYPE.
*/
public String getStringValue()
throws XPathException;
/**
* The value of this boolean result.
* @exception XPathException
* TYPE_ERR: raised if resultType is not
* BOOLEAN_TYPE.
*/
public boolean getBooleanValue()
throws XPathException;
/**
* The value of this single node result, which may be null.
* @exception XPathException
* TYPE_ERR: raised if resultType is not
* ANY_UNORDERED_NODE_TYPE or
* FIRST_ORDERED_NODE_TYPE.
*/
public Node getSingleNodeValue()
throws XPathException;
/**
* 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.
*/
public boolean getInvalidIteratorState();
/**
* The number of nodes in the result snapshot. Valid values for
* snapshotItem indices are 0 to
* snapshotLength-1 inclusive.
* @exception XPathException
* TYPE_ERR: raised if resultType is not
* UNORDERED_NODE_SNAPSHOT_TYPE or
* ORDERED_NODE_SNAPSHOT_TYPE.
*/
public int getSnapshotLength()
throws XPathException;
/**
* Iterates and returns the next node from the node set or
* nullif there are no more nodes.
* @return Returns the next node.
* @exception XPathException
* TYPE_ERR: raised if resultType is not
* UNORDERED_NODE_ITERATOR_TYPE or
* ORDERED_NODE_ITERATOR_TYPE.
* @exception DOMException
* INVALID_STATE_ERR: The document has been mutated since the result was
* returned.
*/
public Node iterateNext()
throws XPathException, DOMException;
/**
* Returns the indexth 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.
* @param index Index into the snapshot collection.
* @return The node at the indexth position in the
* NodeList, or null if that is not a valid
* index.
* @exception XPathException
* TYPE_ERR: raised if resultType is not
* UNORDERED_NODE_SNAPSHOT_TYPE or
* ORDERED_NODE_SNAPSHOT_TYPE.
*/
public Node snapshotItem(int index)
throws XPathException;
}