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1: /* 2: * Copyright (c) 2004 World Wide Web Consortium, 3: * 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. 9: * 10: * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231 11: */ 12: 13: package org.w3c.dom.xpath; 14: 15: import org.w3c.dom.Node; 16: import org.w3c.dom.DOMException; 17: 18: /** 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>. 25: */ 26: public interface XPathResult { 27: // XPathResultType 28: /** 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. 37: */ 38: public static final short ANY_TYPE = 0; 39: /** 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. 43: */ 44: public static final short NUMBER_TYPE = 1; 45: /** 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. 49: */ 50: public static final short STRING_TYPE = 2; 51: /** 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. 55: */ 56: public static final short BOOLEAN_TYPE = 3; 57: /** 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. 63: */ 64: public static final short UNORDERED_NODE_ITERATOR_TYPE = 4; 65: /** 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. 69: */ 70: public static final short ORDERED_NODE_ITERATOR_TYPE = 5; 71: /** 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. 78: */ 79: public static final short UNORDERED_NODE_SNAPSHOT_TYPE = 6; 80: /** 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. 87: */ 88: public static final short ORDERED_NODE_SNAPSHOT_TYPE = 7; 89: /** 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 96: * has been found. 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. 99: */ 100: public static final short ANY_UNORDERED_NODE_TYPE = 8; 101: /** 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. 111: */ 112: public static final short FIRST_ORDERED_NODE_TYPE = 9; 113: 114: /** 115: * A code representing the type of this result, as defined by the type 116: * constants. 117: */ 118: public short getResultType(); 119: 120: /** 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 125: * number. 126: * @exception XPathException 127: * TYPE_ERR: raised if <code>resultType</code> is not 128: * <code>NUMBER_TYPE</code>. 129: */ 130: public double getNumberValue() 131: throws XPathException; 132: 133: /** 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>. 138: */ 139: public String getStringValue() 140: throws XPathException; 141: 142: /** 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>. 147: */ 148: public boolean getBooleanValue() 149: throws XPathException; 150: 151: /** 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>. 157: */ 158: public Node getSingleNodeValue() 159: throws XPathException; 160: 161: /** 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. 166: */ 167: public boolean getInvalidIteratorState(); 168: 169: /** 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>. 177: */ 178: public int getSnapshotLength() 179: throws XPathException; 180: 181: /** 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 191: * returned. 192: */ 193: public Node iterateNext() 194: throws XPathException, DOMException; 195: 196: /** 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 205: * index. 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>. 210: */ 211: public Node snapshotItem(int index) 212: throws XPathException; 213: 214: }