2 * Copyright (c) 2004 World Wide Web Consortium,
4 * (Massachusetts Institute of Technology, European Research Consortium for
5 * Informatics and Mathematics, Keio University). All Rights Reserved. This
6 * work is distributed under the W3C(r) Software License [1] in the hope that
7 * it will be useful, but WITHOUT ANY WARRANTY; without even the implied
8 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
10 * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
13 package org.w3c.dom.xpath;
15 import org.w3c.dom.Node;
16 import org.w3c.dom.DOMException;
19 * The <code>XPathResult</code> interface represents the result of the
20 * evaluation of an XPath 1.0 expression within the context of a particular
21 * node. Since evaluation of an XPath expression can result in various
22 * result types, this object makes it possible to discover and manipulate
23 * the type and value of the result.
24 * <p>See also the <a href='http://www.w3.org/TR/2004/NOTE-DOM-Level-3-XPath-20040226'>Document Object Model (DOM) Level 3 XPath Specification</a>.
26 public interface XPathResult {
29 * This code does not represent a specific type. An evaluation of an XPath
30 * expression will never produce this type. If this type is requested,
31 * then the evaluation returns whatever type naturally results from
32 * evaluation of the expression.
33 * <br>If the natural result is a node set when <code>ANY_TYPE</code> was
34 * requested, then <code>UNORDERED_NODE_ITERATOR_TYPE</code> is always
35 * the resulting type. Any other representation of a node set must be
36 * explicitly requested.
38 public static final short ANY_TYPE = 0;
40 * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#numbers'>number</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>].
41 * Document modification does not invalidate the number, but may mean
42 * that reevaluation would not yield the same number.
44 public static final short NUMBER_TYPE = 1;
46 * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#strings'>string</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>].
47 * Document modification does not invalidate the string, but may mean
48 * that the string no longer corresponds to the current document.
50 public static final short STRING_TYPE = 2;
52 * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#booleans'>boolean</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>].
53 * Document modification does not invalidate the boolean, but may mean
54 * that reevaluation would not yield the same boolean.
56 public static final short BOOLEAN_TYPE = 3;
58 * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#node-sets'>node set</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] that
59 * will be accessed iteratively, which may not produce nodes in a
60 * particular order. Document modification invalidates the iteration.
61 * <br>This is the default type returned if the result is a node set and
62 * <code>ANY_TYPE</code> is requested.
64 public static final short UNORDERED_NODE_ITERATOR_TYPE = 4;
66 * The result is a node set as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] that
67 * will be accessed iteratively, which will produce document-ordered
68 * nodes. Document modification invalidates the iteration.
70 public static final short ORDERED_NODE_ITERATOR_TYPE = 5;
72 * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#node-sets'>node set</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] that
73 * will be accessed as a snapshot list of nodes that may not be in a
74 * particular order. Document modification does not invalidate the
75 * snapshot but may mean that reevaluation would not yield the same
76 * snapshot and nodes in the snapshot may have been altered, moved, or
77 * removed from the document.
79 public static final short UNORDERED_NODE_SNAPSHOT_TYPE = 6;
81 * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#node-sets'>node set</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] that
82 * will be accessed as a snapshot list of nodes that will be in original
83 * document order. Document modification does not invalidate the
84 * snapshot but may mean that reevaluation would not yield the same
85 * snapshot and nodes in the snapshot may have been altered, moved, or
86 * removed from the document.
88 public static final short ORDERED_NODE_SNAPSHOT_TYPE = 7;
90 * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#node-sets'>node set</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] and
91 * will be accessed as a single node, which may be <code>null</code>if
92 * the node set is empty. Document modification does not invalidate the
93 * node, but may mean that the result node no longer corresponds to the
94 * current document. This is a convenience that permits optimization
95 * since the implementation can stop once any node in the resulting set
97 * <br>If there is more than one node in the actual result, the single
98 * node returned might not be the first in document order.
100 public static final short ANY_UNORDERED_NODE_TYPE = 8;
102 * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#node-sets'>node set</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] and
103 * will be accessed as a single node, which may be <code>null</code> if
104 * the node set is empty. Document modification does not invalidate the
105 * node, but may mean that the result node no longer corresponds to the
106 * current document. This is a convenience that permits optimization
107 * since the implementation can stop once the first node in document
108 * order of the resulting set has been found.
109 * <br>If there are more than one node in the actual result, the single
110 * node returned will be the first in document order.
112 public static final short FIRST_ORDERED_NODE_TYPE = 9;
115 * A code representing the type of this result, as defined by the type
118 public short getResultType();
121 * The value of this number result. If the native double type of the DOM
122 * binding does not directly support the exact IEEE 754 result of the
123 * XPath expression, then it is up to the definition of the binding to
124 * specify how the XPath number is converted to the native binding
126 * @exception XPathException
127 * TYPE_ERR: raised if <code>resultType</code> is not
128 * <code>NUMBER_TYPE</code>.
130 public double getNumberValue()
131 throws XPathException;
134 * The value of this string result.
135 * @exception XPathException
136 * TYPE_ERR: raised if <code>resultType</code> is not
137 * <code>STRING_TYPE</code>.
139 public String getStringValue()
140 throws XPathException;
143 * The value of this boolean result.
144 * @exception XPathException
145 * TYPE_ERR: raised if <code>resultType</code> is not
146 * <code>BOOLEAN_TYPE</code>.
148 public boolean getBooleanValue()
149 throws XPathException;
152 * The value of this single node result, which may be <code>null</code>.
153 * @exception XPathException
154 * TYPE_ERR: raised if <code>resultType</code> is not
155 * <code>ANY_UNORDERED_NODE_TYPE</code> or
156 * <code>FIRST_ORDERED_NODE_TYPE</code>.
158 public Node getSingleNodeValue()
159 throws XPathException;
162 * Signifies that the iterator has become invalid. True if
163 * <code>resultType</code> is <code>UNORDERED_NODE_ITERATOR_TYPE</code>
164 * or <code>ORDERED_NODE_ITERATOR_TYPE</code> and the document has been
165 * modified since this result was returned.
167 public boolean getInvalidIteratorState();
170 * The number of nodes in the result snapshot. Valid values for
171 * snapshotItem indices are <code>0</code> to
172 * <code>snapshotLength-1</code> inclusive.
173 * @exception XPathException
174 * TYPE_ERR: raised if <code>resultType</code> is not
175 * <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or
176 * <code>ORDERED_NODE_SNAPSHOT_TYPE</code>.
178 public int getSnapshotLength()
179 throws XPathException;
182 * Iterates and returns the next node from the node set or
183 * <code>null</code>if there are no more nodes.
184 * @return Returns the next node.
185 * @exception XPathException
186 * TYPE_ERR: raised if <code>resultType</code> is not
187 * <code>UNORDERED_NODE_ITERATOR_TYPE</code> or
188 * <code>ORDERED_NODE_ITERATOR_TYPE</code>.
189 * @exception DOMException
190 * INVALID_STATE_ERR: The document has been mutated since the result was
193 public Node iterateNext()
194 throws XPathException, DOMException;
197 * Returns the <code>index</code>th item in the snapshot collection. If
198 * <code>index</code> is greater than or equal to the number of nodes in
199 * the list, this method returns <code>null</code>. Unlike the iterator
200 * result, the snapshot does not become invalid, but may not correspond
201 * to the current document if it is mutated.
202 * @param index Index into the snapshot collection.
203 * @return The node at the <code>index</code>th position in the
204 * <code>NodeList</code>, or <code>null</code> if that is not a valid
206 * @exception XPathException
207 * TYPE_ERR: raised if <code>resultType</code> is not
208 * <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or
209 * <code>ORDERED_NODE_SNAPSHOT_TYPE</code>.
211 public Node snapshotItem(int index)
212 throws XPathException;