| /******************************************************************************* |
| * Copyright (c) 2005 Oracle Corporation. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Ian Trimble - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jst.pagedesigner.dtmanager.converter.operations.internal; |
| |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.StringTokenizer; |
| |
| import javax.xml.namespace.NamespaceContext; |
| import javax.xml.xpath.XPath; |
| import javax.xml.xpath.XPathConstants; |
| import javax.xml.xpath.XPathExpressionException; |
| import javax.xml.xpath.XPathFactory; |
| |
| import org.eclipse.core.runtime.Assert; |
| import org.eclipse.jst.pagedesigner.dtmanager.converter.operations.AbstractTransformOperation; |
| import org.w3c.dom.Element; |
| |
| /** |
| * ITransformOperation implementation that creates a new attribute on the |
| * current Element by getting a value from the specified XPath expression. |
| * |
| * @author Ian Trimble - Oracle |
| */ |
| public class CreateAttributeFromXPathOperation extends AbstractTransformOperation { |
| |
| private static final String DEFAULT_PREFIX = "prefix"; //$NON-NLS-1$ |
| |
| private String attributeName; |
| private String xPathExpression; |
| private String nsURI; |
| private String prefixedTokens; |
| |
| /* |
| * (non-Javadoc) |
| * @see org.eclipse.jst.pagedesigner.dtmanager.converter.operations.internal.provisional.AbstractTransformOperation#transform(org.w3c.dom.Element, org.w3c.dom.Element) |
| */ |
| public Element transform(Element srcElement, Element curElement) { |
| |
| if (getParameters().length < 2) { |
| getLog().error("Warning.TransformOperationFactory.TooFewParameters", getTransformOperationID()); //$NON-NLS-1$ |
| return null; |
| } |
| attributeName = getParameters()[0]; |
| xPathExpression = getParameters()[1]; |
| Assert.isNotNull(attributeName); |
| Assert.isNotNull(xPathExpression); |
| if (getParameters().length > 3) { |
| nsURI = getParameters()[2]; |
| Assert.isNotNull(nsURI); |
| prefixedTokens = getParameters()[3]; |
| Assert.isNotNull(prefixedTokens); |
| } |
| |
| if (srcElement != null) { |
| XPath xPath = XPathFactory.newInstance().newXPath(); |
| try { |
| Object resultObject = xPath.evaluate(xPathExpression, srcElement, XPathConstants.STRING); |
| if (resultObject instanceof String && curElement != null) { |
| if (((String)resultObject).equals("0")) { //$NON-NLS-1$ |
| if (nsURI != null && prefixedTokens != null) { |
| xPath.setNamespaceContext(new NSContext(nsURI, DEFAULT_PREFIX)); |
| resultObject = xPath.evaluate(getPrefixedExpression(DEFAULT_PREFIX), srcElement, XPathConstants.STRING); |
| } |
| } |
| curElement.setAttribute(attributeName, (String)resultObject); |
| } |
| } catch(XPathExpressionException xee) { |
| //could not evaluate - return curElement |
| } |
| } |
| return curElement; |
| } |
| |
| private String getPrefixedExpression(String prefix) { |
| String prefixedExpression = xPathExpression; |
| final List<String> tokens = new ArrayList<String>(); |
| final StringTokenizer tokenizer = new StringTokenizer(prefixedTokens, ","); //$NON-NLS-1$ |
| while (tokenizer.hasMoreTokens()) { |
| tokens.add(tokenizer.nextToken()); |
| } |
| for (String token: tokens) { |
| prefixedExpression = prefixedExpression.replace(token, prefix + ":" + token); //$NON-NLS-1$ |
| } |
| return prefixedExpression; |
| } |
| |
| |
| |
| class NSContext implements NamespaceContext { |
| |
| private String _namespaceURI; |
| private String _prefix; |
| |
| public NSContext(String namespaceURI, String prefix) { |
| _namespaceURI = namespaceURI; |
| _prefix = prefix; |
| } |
| |
| public String getNamespaceURI(String prefix) { |
| return _namespaceURI; |
| } |
| |
| public String getPrefix(String namespaceURI) { |
| return _prefix; |
| } |
| |
| public Iterator getPrefixes(String namespaceURI) { |
| return Arrays.asList(new String[]{_prefix}).iterator(); |
| } |
| |
| } |
| |
| } |