| /******************************************************************************* |
| * Copyright (c) 2008 Standards for Technology in Automotive Retail and others |
| * 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: |
| * David Carver (STAR) - initial API and implementation |
| *******************************************************************************/ |
| |
| package org.eclipse.wst.xml.xpath.core.util; |
| |
| import javax.xml.transform.TransformerException; |
| import javax.xml.xpath.XPathExpressionException; |
| |
| import org.apache.xml.utils.PrefixResolver; |
| import org.apache.xml.utils.PrefixResolverDefault; |
| import org.apache.xpath.XPath; |
| import org.apache.xpath.XPathContext; |
| import org.apache.xpath.compiler.FunctionTable; |
| import org.apache.xpath.jaxp.JAXPPrefixResolver; |
| import org.apache.xpath.objects.XObject; |
| import org.w3c.dom.Attr; |
| import org.w3c.dom.Document; |
| import org.w3c.dom.Node; |
| import org.w3c.dom.NodeList; |
| import org.w3c.dom.traversal.NodeIterator; |
| |
| public class XSLTXPathHelper { |
| |
| /** |
| * Use an XPath string to select a single node. XPath namespace prefixes are |
| * resolved from the context node, which may not be what you want (see the |
| * next method). |
| * |
| * @param contextNode |
| * The node to start searching from. |
| * @param str |
| * A valid XPath string. |
| * @return The first node found that matches the XPath, or null. |
| * |
| * @throws TransformerException |
| */ |
| public static Node selectSingleNode(Node contextNode, String str) |
| throws TransformerException { |
| return selectSingleNode(contextNode, str, contextNode); |
| } |
| |
| /** |
| * Use an XPath string to select a single node. XPath namespace prefixes are |
| * resolved from the namespaceNode. |
| * |
| * @param contextNode |
| * The node to start searching from. |
| * @param str |
| * A valid XPath string. |
| * @param namespaceNode |
| * The node from which prefixes in the XPath will be resolved to |
| * namespaces. |
| * @return The first node found that matches the XPath, or null. |
| * |
| * @throws TransformerException |
| */ |
| public static Node selectSingleNode(Node contextNode, String str, |
| Node namespaceNode) throws TransformerException { |
| |
| // Have the XObject return its result as a NodeSetDTM. |
| NodeIterator nl = selectNodeIterator(contextNode, str, namespaceNode); |
| |
| // Return the first node, or null |
| return nl.nextNode(); |
| } |
| |
| /** |
| * Use an XPath string to select a nodelist. XPath namespace prefixes are |
| * resolved from the contextNode. |
| * |
| * @param contextNode |
| * The node to start searching from. |
| * @param str |
| * A valid XPath string. |
| * @return A NodeIterator, should never be null. |
| * |
| * @throws TransformerException |
| */ |
| public static NodeIterator selectNodeIterator(Node contextNode, String str) |
| throws TransformerException { |
| return selectNodeIterator(contextNode, str, contextNode); |
| } |
| |
| /** |
| * Use an XPath string to select a nodelist. XPath namespace prefixes are |
| * resolved from the namespaceNode. |
| * |
| * @param contextNode |
| * The node to start searching from. |
| * @param str |
| * A valid XPath string. |
| * @param namespaceNode |
| * The node from which prefixes in the XPath will be resolved to |
| * namespaces. |
| * @return A NodeIterator, should never be null. |
| * |
| * @throws TransformerException |
| */ |
| public static NodeIterator selectNodeIterator(Node contextNode, String str, |
| Node namespaceNode) throws TransformerException { |
| |
| // Execute the XPath, and have it return the result |
| XObject list = eval(contextNode, str, namespaceNode); |
| |
| // Have the XObject return its result as a NodeSetDTM. |
| return list.nodeset(); |
| } |
| |
| /** |
| * Use an XPath string to select a nodelist. XPath namespace prefixes are |
| * resolved from the contextNode. |
| * |
| * @param contextNode |
| * The node to start searching from. |
| * @param str |
| * A valid XPath string. |
| * @return A NodeIterator, should never be null. |
| * |
| * @throws TransformerException |
| */ |
| public static NodeList selectNodeList(Node contextNode, String str) |
| throws TransformerException { |
| return selectNodeList(contextNode, str, contextNode); |
| } |
| |
| /** |
| * Use an XPath string to select a nodelist. XPath namespace prefixes are |
| * resolved from the namespaceNode. |
| * |
| * @param contextNode |
| * The node to start searching from. |
| * @param str |
| * A valid XPath string. |
| * @param namespaceNode |
| * The node from which prefixes in the XPath will be resolved to |
| * namespaces. |
| * @return A NodeIterator, should never be null. |
| * |
| * @throws TransformerException |
| */ |
| public static NodeList selectNodeList(Node contextNode, String str, |
| Node namespaceNode) throws TransformerException { |
| |
| // Execute the XPath, and have it return the result |
| XObject list = eval(contextNode, str, namespaceNode); |
| |
| // Return a NodeList. |
| return list.nodelist(); |
| } |
| |
| /** |
| * Evaluate XPath string to an XObject. Using this method, XPath namespace |
| * prefixes will be resolved from the namespaceNode. |
| * |
| * @param contextNode |
| * The node to start searching from. |
| * @param str |
| * A valid XPath string. |
| * @return An XObject, which can be used to obtain a string, number, |
| * nodelist, etc, should never be null. |
| * @see org.apache.xpath.objects.XObject |
| * @see org.apache.xpath.objects.XNull |
| * @see org.apache.xpath.objects.XBoolean |
| * @see org.apache.xpath.objects.XNumber |
| * @see org.apache.xpath.objects.XString |
| * @see org.apache.xpath.objects.XRTreeFrag |
| * |
| * @throws TransformerException |
| */ |
| public static XObject eval(Node contextNode, String str) |
| throws TransformerException { |
| return eval(contextNode, str, contextNode); |
| } |
| |
| /** |
| * Evaluate XPath string to an XObject. XPath namespace prefixes are |
| * resolved from the namespaceNode. The implementation of this is a little |
| * slow, since it creates a number of objects each time it is called. This |
| * could be optimized to keep the same objects around, but then |
| * thread-safety issues would arise. |
| * |
| * @param contextNode |
| * The node to start searching from. |
| * @param str |
| * A valid XPath string. |
| * @param namespaceNode |
| * The node from which prefixes in the XPath will be resolved to |
| * namespaces. |
| * @return An XObject, which can be used to obtain a string, number, |
| * nodelist, etc, should never be null. |
| * @see org.apache.xpath.objects.XObject |
| * @see org.apache.xpath.objects.XNull |
| * @see org.apache.xpath.objects.XBoolean |
| * @see org.apache.xpath.objects.XNumber |
| * @see org.apache.xpath.objects.XString |
| * @see org.apache.xpath.objects.XRTreeFrag |
| * |
| * @throws TransformerException |
| * |
| */ |
| public static XObject eval(Node contextNode, String str, Node namespaceNode) |
| throws TransformerException { |
| |
| // Since we don't have a XML Parser involved here, install some default |
| // support |
| // for things like namespaces, etc. |
| // (Changed from: XPathContext xpathSupport = new XPathContext(); |
| // because XPathContext is weak in a number of areas... perhaps |
| // XPathContext should be done away with.) |
| XPathContext xpathSupport = new XPathContext(); |
| |
| // Create an object to resolve namespace prefixes. |
| // XPath namespaces are resolved from the input context node's document |
| // element |
| // if it is a root node, or else the current context node (for lack of a |
| // better |
| // resolution space, given the simplicity of this sample code). |
| PrefixResolverDefault prefixResolver = new PrefixResolverDefault( |
| (namespaceNode.getNodeType() == Node.DOCUMENT_NODE) ? ((Document) namespaceNode) |
| .getDocumentElement() |
| : namespaceNode); |
| |
| // Create the XPath object. |
| XPath xpath = new XPath(str, null, prefixResolver, XPath.SELECT, null, |
| getFunctionTable()); |
| |
| // Execute the XPath, and have it return the result |
| // return xpath.execute(xpathSupport, contextNode, prefixResolver); |
| int ctxtNode = xpathSupport.getDTMHandleFromNode(contextNode); |
| |
| return xpath.execute(xpathSupport, ctxtNode, prefixResolver); |
| } |
| |
| /** |
| * Evaluate XPath string to an XObject. XPath namespace prefixes are |
| * resolved from the namespaceNode. The implementation of this is a little |
| * slow, since it creates a number of objects each time it is called. This |
| * could be optimized to keep the same objects around, but then |
| * thread-safety issues would arise. |
| * |
| * @param contextNode |
| * The node to start searching from. |
| * @param str |
| * A valid XPath string. |
| * @param prefixResolver |
| * Will be called if the parser encounters namespace prefixes, to |
| * resolve the prefixes to URLs. |
| * @return An XObject, which can be used to obtain a string, number, |
| * nodelist, etc, should never be null. |
| * @see org.apache.xpath.objects.XObject |
| * @see org.apache.xpath.objects.XNull |
| * @see org.apache.xpath.objects.XBoolean |
| * @see org.apache.xpath.objects.XNumber |
| * @see org.apache.xpath.objects.XString |
| * @see org.apache.xpath.objects.XRTreeFrag |
| * |
| * @throws TransformerException |
| */ |
| public static XObject eval(Node contextNode, String str, |
| PrefixResolver prefixResolver) throws TransformerException { |
| |
| // Since we don't have a XML Parser involved here, install some default |
| // support |
| // for things like namespaces, etc. |
| // (Changed from: XPathContext xpathSupport = new XPathContext(); |
| // because XPathContext is weak in a number of areas... perhaps |
| // XPathContext should be done away with.) |
| // Create the XPath object. |
| XPath xpath = new XPath(str, null, prefixResolver, XPath.SELECT, null, |
| getFunctionTable()); |
| |
| // Execute the XPath, and have it return the result |
| XPathContext xpathSupport = new XPathContext(); |
| int ctxtNode = xpathSupport.getDTMHandleFromNode(contextNode); |
| |
| return xpath.execute(xpathSupport, ctxtNode, prefixResolver); |
| } |
| |
| public static void compile(String expression) |
| throws XPathExpressionException { |
| try { |
| new XPath(expression, null, null, org.apache.xpath.XPath.SELECT, |
| null, getFunctionTable()); |
| } catch (javax.xml.transform.TransformerException te) { |
| throw new XPathExpressionException(te); |
| } |
| |
| } |
| |
| protected static FunctionTable getFunctionTable() { |
| FunctionTable functionTable = new FunctionTable(); |
| functionTable.installFunction("key", |
| org.apache.xalan.templates.FuncKey.class); |
| functionTable.installFunction("format-number", |
| org.apache.xalan.templates.FuncFormatNumb.class); |
| functionTable.installFunction("document", |
| org.apache.xalan.templates.FuncDocument.class); |
| functionTable.installFunction("element-available", |
| org.apache.xpath.functions.FuncExtElementAvailable.class); |
| functionTable.installFunction("function-available", |
| org.apache.xpath.functions.FuncExtFunctionAvailable.class); |
| functionTable.installFunction("current", |
| org.apache.xpath.functions.FuncCurrent.class); |
| functionTable.installFunction("unparsed-entity-string", |
| org.apache.xpath.functions.FuncUnparsedEntityURI.class); |
| functionTable.installFunction("generate-id", |
| org.apache.xpath.functions.FuncGenerateId.class); |
| functionTable.installFunction("system-property", |
| org.apache.xpath.functions.FuncSystemProperty.class); |
| return functionTable; |
| } |
| |
| /** |
| * Returns a XPath expression given a DOM Node. |
| * |
| * @param node |
| * The DOM Node to create the XPath expression. |
| * @since 1.0 |
| */ |
| public static String calculateXPathToNode(Node node) { |
| Node xpathNode = node; |
| StringBuffer sb = new StringBuffer(); |
| while (xpathNode != null) { |
| switch (xpathNode.getNodeType()) { |
| case Node.ATTRIBUTE_NODE: |
| sb.insert(0, xpathNode.getNodeName()); |
| sb.insert(0, "/@"); //$NON-NLS-1$ |
| xpathNode = ((Attr) xpathNode).getOwnerElement(); |
| break; |
| case Node.ELEMENT_NODE: |
| Node sibling = xpathNode; |
| int position = 1; |
| while ((sibling = sibling.getPreviousSibling()) != null) { |
| if (sibling.getNodeType() == Node.ELEMENT_NODE |
| && sibling.getNodeName().equals(xpathNode.getNodeName())) { |
| ++position; |
| } |
| } |
| if (position > 1) { |
| sb.insert(0, "[" + position + "]"); //$NON-NLS-1$ //$NON-NLS-2$ |
| } |
| else { |
| sibling = xpathNode.getNextSibling(); |
| boolean following = false; |
| while (sibling != null) { |
| if (sibling.getNodeType() == Node.ELEMENT_NODE |
| && sibling.getNodeName().equals( |
| xpathNode.getNodeName())) { |
| following = true; |
| break; |
| } |
| sibling = sibling.getNextSibling(); |
| } |
| if (following) { |
| sb.insert(0, "[1]"); //$NON-NLS-1$ |
| } |
| } |
| sb.insert(0, xpathNode.getNodeName()); |
| sb.insert(0, "/"); //$NON-NLS-1$ |
| xpathNode = xpathNode.getParentNode(); |
| break; |
| default: |
| xpathNode = xpathNode.getParentNode(); |
| } |
| } |
| return sb.toString(); |
| } |
| |
| } |
