| 1 | package org.apache.velocity.anakia; |
| 2 | |
| 3 | /* |
| 4 | * Copyright 2001,2004 The Apache Software Foundation. |
| 5 | * |
| 6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 7 | * you may not use this file except in compliance with the License. |
| 8 | * You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, software |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | * See the License for the specific language governing permissions and |
| 16 | * limitations under the License. |
| 17 | */ |
| 18 | |
| 19 | import java.util.List; |
| 20 | |
| 21 | import org.jdom.Document; |
| 22 | import org.jdom.Element; |
| 23 | |
| 24 | /** |
| 25 | * This class adds an entrypoint into XPath functionality, |
| 26 | * for Anakia. |
| 27 | * <p> |
| 28 | * All methods take a string XPath specification, along with |
| 29 | * a context, and produces a resulting java.util.List. |
| 30 | * <p> |
| 31 | * The W3C XPath Specification (http://www.w3.org/TR/xpath) refers |
| 32 | * to NodeSets repeatedly, but this implementation simply uses |
| 33 | * java.util.List to hold all Nodes. A 'Node' is any object in |
| 34 | * a JDOM object tree, such as an org.jdom.Element, org.jdom.Document, |
| 35 | * or org.jdom.Attribute. |
| 36 | * <p> |
| 37 | * To use it in Velocity, do this: |
| 38 | * <p> |
| 39 | * <pre> |
| 40 | * #set $authors = $xpath.applyTo("document/author", $root) |
| 41 | * #foreach ($author in $authors) |
| 42 | * $author.getValue() |
| 43 | * #end |
| 44 | * #set $chapterTitles = $xpath.applyTo("document/chapter/@title", $root) |
| 45 | * #foreach ($title in $chapterTitles) |
| 46 | * $title.getValue() |
| 47 | * #end |
| 48 | * </pre> |
| 49 | * <p> |
| 50 | * In newer Anakia builds, this class is obsoleted in favor of calling |
| 51 | * <code>selectNodes()</code> on the element directly: |
| 52 | * <pre> |
| 53 | * #set $authors = $root.selectNodes("document/author") |
| 54 | * #foreach ($author in $authors) |
| 55 | * $author.getValue() |
| 56 | * #end |
| 57 | * #set $chapterTitles = $root.selectNodes("document/chapter/@title") |
| 58 | * #foreach ($title in $chapterTitles) |
| 59 | * $title.getValue() |
| 60 | * #end |
| 61 | * </pre> |
| 62 | * <p> |
| 63 | * |
| 64 | * @author <a href="mailto:bob@werken.com">bob mcwhirter</a> |
| 65 | * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a> |
| 66 | * @author <a href="mailto:szegedia@freemail.hu">Attila Szegedi</a> |
| 67 | * @version $Id: XPathTool.java,v 1.13.4.1 2004/03/03 23:22:04 geirm Exp $ |
| 68 | */ |
| 69 | public class XPathTool |
| 70 | { |
| 71 | /** |
| 72 | * Constructor does nothing, as this is mostly |
| 73 | * just objectified static methods |
| 74 | */ |
| 75 | public XPathTool() |
| 76 | { |
| 77 | // RuntimeSingleton.info("XPathTool::XPathTool()"); |
| 78 | // intentionally left blank |
| 79 | } |
| 80 | |
| 81 | /** |
| 82 | * Apply an XPath to a JDOM Document |
| 83 | * |
| 84 | * @param xpathSpec The XPath to apply |
| 85 | * @param doc The Document context |
| 86 | * |
| 87 | * @return A list of selected nodes |
| 88 | */ |
| 89 | public NodeList applyTo(String xpathSpec, |
| 90 | Document doc) |
| 91 | { |
| 92 | //RuntimeSingleton.info("XPathTool::applyTo(String, Document)"); |
| 93 | return new NodeList(XPathCache.getXPath(xpathSpec).applyTo( doc ), false); |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * Apply an XPath to a JDOM Element |
| 98 | * |
| 99 | * @param xpathSpec The XPath to apply |
| 100 | * @param doc The Element context |
| 101 | * |
| 102 | * @return A list of selected nodes |
| 103 | */ |
| 104 | public NodeList applyTo(String xpathSpec, |
| 105 | Element elem) |
| 106 | { |
| 107 | //RuntimeSingleton.info("XPathTool::applyTo(String, Element)"); |
| 108 | return new NodeList(XPathCache.getXPath(xpathSpec).applyTo( elem ), false); |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * Apply an XPath to a nodeset |
| 113 | * |
| 114 | * @param xpathSpec The XPath to apply |
| 115 | * @param doc The nodeset context |
| 116 | * |
| 117 | * @return A list of selected nodes |
| 118 | */ |
| 119 | public NodeList applyTo(String xpathSpec, |
| 120 | List nodeSet) |
| 121 | { |
| 122 | //RuntimeSingleton.info("XPathTool::applyTo(String, List)"); |
| 123 | return new NodeList(XPathCache.getXPath(xpathSpec).applyTo( nodeSet ), false); |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | |
| 128 | |