org.apache.velocity.anakia.XPathTool Maven / Gradle / Ivy
package org.apache.velocity.anakia;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
import java.util.List;
import org.jdom.Document;
import org.jdom.Element;
/**
* This class adds an entrypoint into XPath functionality,
* for Anakia.
*
* All methods take a string XPath specification, along with
* a context, and produces a resulting java.util.List.
*
* The W3C XPath Specification (http://www.w3.org/TR/xpath) refers
* to NodeSets repeatedly, but this implementation simply uses
* java.util.List to hold all Nodes. A 'Node' is any object in
* a JDOM object tree, such as an org.jdom.Element, org.jdom.Document,
* or org.jdom.Attribute.
*
* To use it in Velocity, do this:
*
*
* #set $authors = $xpath.applyTo("document/author", $root)
* #foreach ($author in $authors)
* $author.getValue()
* #end
* #set $chapterTitles = $xpath.applyTo("document/chapter/@title", $root)
* #foreach ($title in $chapterTitles)
* $title.getValue()
* #end
*
*
* In newer Anakia builds, this class is obsoleted in favor of calling
* selectNodes() on the element directly:
*
* #set $authors = $root.selectNodes("document/author")
* #foreach ($author in $authors)
* $author.getValue()
* #end
* #set $chapterTitles = $root.selectNodes("document/chapter/@title")
* #foreach ($title in $chapterTitles)
* $title.getValue()
* #end
*
*
*
* @author bob mcwhirter
* @author Jon S. Stevens
* @author Attila Szegedi
* @version $Id: XPathTool.java 463298 2006-10-12 16:10:32Z henning $
*/
public class XPathTool
{
/**
* Constructor does nothing, as this is mostly
* just objectified static methods
*/
public XPathTool()
{
// RuntimeSingleton.info("XPathTool::XPathTool()");
// intentionally left blank
}
/**
* Apply an XPath to a JDOM Document
*
* @param xpathSpec The XPath to apply
* @param doc The Document context
*
* @return A list of selected nodes
*/
public NodeList applyTo(String xpathSpec,
Document doc)
{
//RuntimeSingleton.info("XPathTool::applyTo(String, Document)");
return new NodeList(XPathCache.getXPath(xpathSpec).applyTo( doc ), false);
}
/**
* Apply an XPath to a JDOM Element
*
* @param xpathSpec The XPath to apply
* @param elem The Element context
*
* @return A list of selected nodes
*/
public NodeList applyTo(String xpathSpec,
Element elem)
{
//RuntimeSingleton.info("XPathTool::applyTo(String, Element)");
return new NodeList(XPathCache.getXPath(xpathSpec).applyTo( elem ), false);
}
/**
* Apply an XPath to a nodeset
*
* @param xpathSpec The XPath to apply
* @param nodeSet The nodeset context
*
* @return A list of selected nodes
*/
public NodeList applyTo(String xpathSpec,
List nodeSet)
{
//RuntimeSingleton.info("XPathTool::applyTo(String, List)");
return new NodeList(XPathCache.getXPath(xpathSpec).applyTo( nodeSet ), false);
}
}