1/*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
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9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
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24
25/*
26 * This file is available under and governed by the GNU General Public
27 * License version 2 only, as published by the Free Software Foundation.
28 * However, the following notice accompanied the original version of this
29 * file and, per its terms, should not be removed:
30 *
31 * Copyright (c) 2002 World Wide Web Consortium,
32 * (Massachusetts Institute of Technology, Institut National de
33 * Recherche en Informatique et en Automatique, Keio University). All
34 * Rights Reserved. This program is distributed under the W3C's Software
35 * Intellectual Property License. This program is distributed in the
36 * hope that it will be useful, but WITHOUT ANY WARRANTY; without even
37 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
38 * PURPOSE.
39 * See W3C License http://www.w3.org/Consortium/Legal/ for more details.
40 */
41
42package org.w3c.dom.xpath;
43
44
45import org.w3c.dom.Node;
46import org.w3c.dom.DOMException;
47
48/**
49 * The <code>XPathResult</code> interface represents the result of the
50 * evaluation of an XPath 1.0 expression within the context of a particular
51 * node. Since evaluation of an XPath expression can result in various
52 * result types, this object makes it possible to discover and manipulate
53 * the type and value of the result.
54 * <p>See also the <a href='http://www.w3.org/2002/08/WD-DOM-Level-3-XPath-20020820'>Document Object Model (DOM) Level 3 XPath Specification</a>.
55 */
56public interface XPathResult {
57    // XPathResultType
58    /**
59     * This code does not represent a specific type. An evaluation of an XPath
60     * expression will never produce this type. If this type is requested,
61     * then the evaluation returns whatever type naturally results from
62     * evaluation of the expression.
63     * <br>If the natural result is a node set when <code>ANY_TYPE</code> was
64     * requested, then <code>UNORDERED_NODE_ITERATOR_TYPE</code> is always
65     * the resulting type. Any other representation of a node set must be
66     * explicitly requested.
67     */
68    public static final short ANY_TYPE                  = 0;
69    /**
70     * The result is a number as defined by . Document modification does not
71     * invalidate the number, but may mean that reevaluation would not yield
72     * the same number.
73     */
74    public static final short NUMBER_TYPE               = 1;
75    /**
76     * The result is a string as defined by . Document modification does not
77     * invalidate the string, but may mean that the string no longer
78     * corresponds to the current document.
79     */
80    public static final short STRING_TYPE               = 2;
81    /**
82     * The result is a boolean as defined by . Document modification does not
83     * invalidate the boolean, but may mean that reevaluation would not
84     * yield the same boolean.
85     */
86    public static final short BOOLEAN_TYPE              = 3;
87    /**
88     * The result is a node set as defined by  that will be accessed
89     * iteratively, which may not produce nodes in a particular order.
90     * Document modification invalidates the iteration.
91     * <br>This is the default type returned if the result is a node set and
92     * <code>ANY_TYPE</code> is requested.
93     */
94    public static final short UNORDERED_NODE_ITERATOR_TYPE = 4;
95    /**
96     * The result is a node set as defined by  that will be accessed
97     * iteratively, which will produce document-ordered nodes. Document
98     * modification invalidates the iteration.
99     */
100    public static final short ORDERED_NODE_ITERATOR_TYPE = 5;
101    /**
102     * The result is a node set as defined by  that will be accessed as a
103     * snapshot list of nodes that may not be in a particular order.
104     * Document modification does not invalidate the snapshot but may mean
105     * that reevaluation would not yield the same snapshot and nodes in the
106     * snapshot may have been altered, moved, or removed from the document.
107     */
108    public static final short UNORDERED_NODE_SNAPSHOT_TYPE = 6;
109    /**
110     * The result is a node set as defined by  that will be accessed as a
111     * snapshot list of nodes that will be in original document order.
112     * Document modification does not invalidate the snapshot but may mean
113     * that reevaluation would not yield the same snapshot and nodes in the
114     * snapshot may have been altered, moved, or removed from the document.
115     */
116    public static final short ORDERED_NODE_SNAPSHOT_TYPE = 7;
117    /**
118     * The result is a node set as defined by  and will be accessed as a
119     * single node, which may be <code>null</code>if the node set is empty.
120     * Document modification does not invalidate the node, but may mean that
121     * the result node no longer corresponds to the current document. This
122     * is a convenience that permits optimization since the implementation
123     * can stop once any node in the in the resulting set has been found.
124     * <br>If there are more than one node in the actual result, the single
125     * node returned might not be the first in document order.
126     */
127    public static final short ANY_UNORDERED_NODE_TYPE   = 8;
128    /**
129     * The result is a node set as defined by  and will be accessed as a
130     * single node, which may be <code>null</code> if the node set is empty.
131     * Document modification does not invalidate the node, but may mean that
132     * the result node no longer corresponds to the current document. This
133     * is a convenience that permits optimization since the implementation
134     * can stop once the first node in document order of the resulting set
135     * has been found.
136     * <br>If there are more than one node in the actual result, the single
137     * node returned will be the first in document order.
138     */
139    public static final short FIRST_ORDERED_NODE_TYPE   = 9;
140
141    /**
142     * A code representing the type of this result, as defined by the type
143     * constants.
144     */
145    public short getResultType();
146
147    /**
148     * The value of this number result. If the native double type of the DOM
149     * binding does not directly support the exact IEEE 754 result of the
150     * XPath expression, then it is up to the definition of the binding
151     * binding to specify how the XPath number is converted to the native
152     * binding number.
153     * @exception XPathException
154     *   TYPE_ERR: raised if <code>resultType</code> is not
155     *   <code>NUMBER_TYPE</code>.
156     */
157    public double getNumberValue()
158                             throws XPathException;
159
160    /**
161     * The value of this string result.
162     * @exception XPathException
163     *   TYPE_ERR: raised if <code>resultType</code> is not
164     *   <code>STRING_TYPE</code>.
165     */
166    public String getStringValue()
167                             throws XPathException;
168
169    /**
170     * The value of this boolean result.
171     * @exception XPathException
172     *   TYPE_ERR: raised if <code>resultType</code> is not
173     *   <code>BOOLEAN_TYPE</code>.
174     */
175    public boolean getBooleanValue()
176                             throws XPathException;
177
178    /**
179     * The value of this single node result, which may be <code>null</code>.
180     * @exception XPathException
181     *   TYPE_ERR: raised if <code>resultType</code> is not
182     *   <code>ANY_UNORDERED_NODE_TYPE</code> or
183     *   <code>FIRST_ORDERED_NODE_TYPE</code>.
184     */
185    public Node getSingleNodeValue()
186                             throws XPathException;
187
188    /**
189     * Signifies that the iterator has become invalid. True if
190     * <code>resultType</code> is <code>UNORDERED_NODE_ITERATOR_TYPE</code>
191     * or <code>ORDERED_NODE_ITERATOR_TYPE</code> and the document has been
192     * modified since this result was returned.
193     */
194    public boolean getInvalidIteratorState();
195
196    /**
197     * The number of nodes in the result snapshot. Valid values for
198     * snapshotItem indices are <code>0</code> to
199     * <code>snapshotLength-1</code> inclusive.
200     * @exception XPathException
201     *   TYPE_ERR: raised if <code>resultType</code> is not
202     *   <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or
203     *   <code>ORDERED_NODE_SNAPSHOT_TYPE</code>.
204     */
205    public int getSnapshotLength()
206                             throws XPathException;
207
208    /**
209     * Iterates and returns the next node from the node set or
210     * <code>null</code>if there are no more nodes.
211     * @return Returns the next node.
212     * @exception XPathException
213     *   TYPE_ERR: raised if <code>resultType</code> is not
214     *   <code>UNORDERED_NODE_ITERATOR_TYPE</code> or
215     *   <code>ORDERED_NODE_ITERATOR_TYPE</code>.
216     * @exception DOMException
217     *   INVALID_STATE_ERR: The document has been mutated since the result was
218     *   returned.
219     */
220    public Node iterateNext()
221                            throws XPathException, DOMException;
222
223    /**
224     * Returns the <code>index</code>th item in the snapshot collection. If
225     * <code>index</code> is greater than or equal to the number of nodes in
226     * the list, this method returns <code>null</code>. Unlike the iterator
227     * result, the snapshot does not become invalid, but may not correspond
228     * to the current document if it is mutated.
229     * @param index Index into the snapshot collection.
230     * @return The node at the <code>index</code>th position in the
231     *   <code>NodeList</code>, or <code>null</code> if that is not a valid
232     *   index.
233     * @exception XPathException
234     *   TYPE_ERR: raised if <code>resultType</code> is not
235     *   <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or
236     *   <code>ORDERED_NODE_SNAPSHOT_TYPE</code>.
237     */
238    public Node snapshotItem(int index)
239                             throws XPathException;
240
241}
242