| /* |
| * Copyright (c) 2002 World Wide Web Consortium, |
| * (Massachusetts Institute of Technology, Institut National de |
| * Recherche en Informatique et en Automatique, Keio University). All |
| * Rights Reserved. This program is distributed under the W3C's Software |
| * Intellectual Property License. This program is distributed in the |
| * hope that it will be useful, but WITHOUT ANY WARRANTY; without even |
| * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR |
| * PURPOSE. |
| * See W3C License http://www.w3.org/Consortium/Legal/ for more details. |
| */ |
| |
| package org.w3c.dom.xpath; |
| |
| import org.w3c.dom.Node; |
| import org.w3c.dom.DOMException; |
| |
| /** |
| * The <code>XPathResult</code> interface represents the result of the |
| * evaluation of an XPath 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.Should there be a flag on the result to |
| * say whether an iteration has become invalid?Yes.Added the boolean |
| * attribute <code>invalidIteratorState</code>Should there be a reset method |
| * on the result in case someone wants to iterate the result multiple times? |
| * It may be more trouble than it is worth, because the user can request a |
| * new query. See if there are use cases.It might be better to consolidate |
| * the interfaces and just move the snapshot and iterator functions to the |
| * result object.Yes.The result of the consolidation looks good and unless |
| * there are great objections, this is how it will be.There is concern that |
| * the result cannot represent multiple strings, which is a possible result |
| * of XPath 2.0. on them?No change.This is not part of the XPath 1.0 data |
| * model. We cannot plan well for the XPath 2.0 data model at this point. |
| * Most likely a new API will be required for XPath 2.0 |
| * <p>See also the <a href='http://www.w3.org/TR/2002/WD-DOM-Level-3-XPath-20020328'>Document Object Model (DOM) Level 3 XPath Specification</a>. |
| */ |
| 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. |
| * <br>If the natural result is a node set when <code>ANY_TYPE</code> was |
| * requested, then <code>UNORDERED_NODE_ITERATOR_TYPE</code> 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 . 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 . 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 . 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 that will be accessed |
| * iteratively, which may not produce nodes in a particular order. |
| * Document modification invalidates the iteration. |
| * <br>This is the default type returned if the result is a node set and |
| * <code>ANY_TYPE</code> is requested. |
| */ |
| public static final short UNORDERED_NODE_ITERATOR_TYPE = 4; |
| /** |
| * The result is a node set as defined by 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 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 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 and will be accessed as a |
| * single node, which may be <code>null</code>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. |
| * <br>If there are more than one node in the actual result, the single |
| * node returned may 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 and will be accessed as a |
| * single node, which may be <code>null</code> 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. |
| * <br>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. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>NUMBER_TYPE</code>. |
| */ |
| public double getNumberValue() |
| throws XPathException; |
| |
| /** |
| * The value of this string result. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>STRING_TYPE</code>. |
| */ |
| public String getStringValue() |
| throws XPathException; |
| |
| /** |
| * The value of this boolean result. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>BOOLEAN_TYPE</code>. |
| */ |
| public boolean getBooleanValue() |
| throws XPathException; |
| |
| /** |
| * The value of this single node result, which may be <code>null</code>. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>ANY_UNORDERED_NODE_TYPE</code> or |
| * <code>FIRST_ORDERED_NODE_TYPE</code>. |
| */ |
| public Node getSingleNodeValue() |
| throws XPathException; |
| |
| /** |
| * Signifies that the iterator has become invalid. True if |
| * <code>resultType</code> is <code>UNORDERED_NODE_ITERATOR_TYPE</code> |
| * or <code>ORDERED_NODE_ITERATOR_TYPE</code> 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 <code>0</code> to |
| * <code>snapshotLength-1</code> inclusive. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or |
| * <code>ORDERED_NODE_SNAPSHOT_TYPE</code>. |
| */ |
| public int getSnapshotLength() |
| throws XPathException; |
| |
| /** |
| * Iterates and returns the next node from the node set or |
| * <code>null</code>if there are no more nodes. |
| * @return Returns the next node. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>UNORDERED_NODE_ITERATOR_TYPE</code> or |
| * <code>ORDERED_NODE_ITERATOR_TYPE</code>. |
| * @exception DOMException |
| * INVALID_STATE_ERR: The document has been mutated since the result was |
| * returned. |
| */ |
| public Node iterateNext() |
| throws XPathException, DOMException; |
| |
| /** |
| * Returns the <code>index</code>th item in the snapshot collection. If |
| * <code>index</code> is greater than or equal to the number of nodes in |
| * the list, this method returns <code>null</code>. 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 <code>index</code>th position in the |
| * <code>NodeList</code>, or <code>null</code> if that is not a valid |
| * index. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or |
| * <code>ORDERED_NODE_SNAPSHOT_TYPE</code>. |
| */ |
| public Node snapshotItem(int index) |
| throws XPathException; |
| |
| } |