| /******************************************************************************* |
| * 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 javax.xml.xpath.XPath; |
| import javax.xml.xpath.XPathConstants; |
| import javax.xml.xpath.XPathExpressionException; |
| import javax.xml.xpath.XPathFactory; |
| |
| import org.eclipse.jst.pagedesigner.dtmanager.converter.operations.AbstractTransformOperation; |
| import org.w3c.dom.Element; |
| |
| /** |
| * ITransformOperation implementation that executes child ITransformOperation |
| * instances if the XPath expression evaluated against the source Element |
| * instance returns a "true" result. |
| * |
| * <br><b>Note:</b> requires ITransformOperation.setTagConverterContext(...) to |
| * have been called to provide a valid ITagConverterContext instance prior to |
| * a call to the transform(...) method. |
| * |
| * @author Ian Trimble - Oracle |
| */ |
| public class IfOperation extends AbstractTransformOperation { |
| |
| private String xPathExpression; |
| |
| /** |
| * Constructs an instance with the specified XPath expression. |
| * |
| * @param xPathExpression XPath expression to be evaluated against the |
| * source Element instance. |
| */ |
| public IfOperation(String xPathExpression) { |
| this.xPathExpression = xPathExpression; |
| } |
| |
| /* |
| * (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) { |
| Element retElement = curElement; |
| if (srcElement != null) { |
| XPath xPath = XPathFactory.newInstance().newXPath(); |
| try { |
| Object resultObject = xPath.evaluate(xPathExpression, srcElement, XPathConstants.BOOLEAN); |
| if (((Boolean)resultObject).booleanValue()) { |
| retElement = executeChildOperations(srcElement, retElement); |
| } |
| } catch(XPathExpressionException xee) { |
| //could not evaluate - return curElement |
| } |
| } |
| return retElement; |
| } |
| |
| } |