/* * reserved comment block * DO NOT REMOVE OR ALTER! */ /* * Copyright 2002-2005 The Apache Software Foundation. * * Licensed 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. */ /* * $Id: XPathExpressionImpl.java,v 1.2.4.1 2005/09/10 04:06:55 jeffsuttor Exp $ */ package com.sun.org.apache.xpath.internal.domapi; import javax.xml.transform.TransformerException; import com.sun.org.apache.xpath.internal.XPath; import com.sun.org.apache.xpath.internal.XPathContext; import com.sun.org.apache.xpath.internal.objects.XObject; import com.sun.org.apache.xpath.internal.res.XPATHErrorResources; import com.sun.org.apache.xpath.internal.res.XPATHMessages; import org.w3c.dom.DOMException; import org.w3c.dom.Document; import org.w3c.dom.Node; import org.w3c.dom.xpath.XPathException; import org.w3c.dom.xpath.XPathExpression; import org.w3c.dom.xpath.XPathNamespace; /** * * The class provides an implementation of XPathExpression according * to the DOM L3 XPath Specification, Working Group Note 26 February 2004. * *

See also the Document Object Model (DOM) Level 3 XPath Specification.

* *

The XPathExpression interface represents a parsed and resolved * XPath expression.

* * @see org.w3c.dom.xpath.XPathExpression * * @xsl.usage internal */ class XPathExpressionImpl implements XPathExpression { /** * The xpath object that this expression wraps */ final private XPath m_xpath; /** * The document to be searched to parallel the case where the XPathEvaluator * is obtained by casting a Document. */ final private Document m_doc; /** * Constructor for XPathExpressionImpl. * * @param xpath The wrapped XPath object. * @param doc The document to be searched, to parallel the case where'' * the XPathEvaluator is obtained by casting the document. */ XPathExpressionImpl(XPath xpath, Document doc) { m_xpath = xpath; m_doc = doc; } /** * * This method provides an implementation XPathResult.evaluate according * to the DOM L3 XPath Specification, Working Group Note 26 February 2004. * *

See also the Document Object Model (DOM) Level 3 XPath Specification.

* *

Evaluates this XPath expression and returns a result.

* @param contextNode The context is context node for the * evaluation of this XPath expression.If the XPathEvaluator was * obtained by casting the Document then this must be * owned by the same document and must be a Document, * Element, Attribute, Text, * CDATASection, Comment, * ProcessingInstruction, or XPathNamespace * node.If the context node is a Text or a * CDATASection, then the context is interpreted as the * whole logical text node as seen by XPath, unless the node is empty * in which case it may not serve as the XPath context. * @param type If a specific type is specified, then the * result will be coerced to return the specified type relying on * XPath conversions and fail if the desired coercion is not possible. * This must be one of the type codes of XPathResult. * @param result The result specifies a specific result * object which may be reused and returned by this method. If this is * specified as nullor the implementation does not reuse * the specified result, a new result object will be constructed and * returned.For XPath 1.0 results, this object will be of type * XPathResult. * @return The result of the evaluation of the XPath expression.For XPath * 1.0 results, this object will be of type XPathResult. * @exception XPathException * TYPE_ERR: Raised if the result cannot be converted to return the * specified type. * @exception DOMException * WRONG_DOCUMENT_ERR: The Node is from a document that is not supported * by the XPathEvaluator that created this * XPathExpression. *
NOT_SUPPORTED_ERR: The Node is not a type permitted as an XPath * context node. * * @see org.w3c.dom.xpath.XPathExpression#evaluate(Node, short, XPathResult) * @xsl.usage internal */ public Object evaluate( Node contextNode, short type, Object result) throws XPathException, DOMException { // If the XPathEvaluator was determined by "casting" the document if (m_doc != null) { // Check that the context node is owned by the same document if ((contextNode != m_doc) && (!contextNode.getOwnerDocument().equals(m_doc))) { String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_WRONG_DOCUMENT, null); throw new DOMException(DOMException.WRONG_DOCUMENT_ERR, fmsg); } // Check that the context node is an acceptable node type short nodeType = contextNode.getNodeType(); if ((nodeType != Document.DOCUMENT_NODE) && (nodeType != Document.ELEMENT_NODE) && (nodeType != Document.ATTRIBUTE_NODE) && (nodeType != Document.TEXT_NODE) && (nodeType != Document.CDATA_SECTION_NODE) && (nodeType != Document.COMMENT_NODE) && (nodeType != Document.PROCESSING_INSTRUCTION_NODE) && (nodeType != XPathNamespace.XPATH_NAMESPACE_NODE)) { String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_WRONG_NODETYPE, null); throw new DOMException(DOMException.NOT_SUPPORTED_ERR, fmsg); } } // // If the type is not a supported type, throw an exception and be // done with it! if (!XPathResultImpl.isValidType(type)) { String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_INVALID_XPATH_TYPE, new Object[] {new Integer(type)}); throw new XPathException(XPathException.TYPE_ERR,fmsg); // Invalid XPath type argument: {0} } // Cache xpath context? XPathContext xpathSupport = new XPathContext(); // if m_document is not null, build the DTM from the document if (null != m_doc) { xpathSupport.getDTMHandleFromNode(m_doc); } XObject xobj = null; try { xobj = m_xpath.execute(xpathSupport, contextNode, null); } catch (TransformerException te) { // What should we do here? throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,te.getMessageAndLocation()); } // Create a new XPathResult object // Reuse result object passed in? // The constructor will check the compatibility of type and xobj and // throw an exception if they are not compatible. return new XPathResultImpl(type,xobj,contextNode, m_xpath); } }