| /* |
| * 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. |
| */ |
| /* |
| * $Id$ |
| */ |
| |
| |
| package org.apache.xpath.domapi; |
| |
| import javax.xml.transform.TransformerException; |
| |
| import org.apache.xpath.XPath; |
| import org.apache.xpath.XPathContext; |
| import org.apache.xpath.objects.XObject; |
| import org.apache.xpath.res.XPATHErrorResources; |
| import org.apache.xpath.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. |
| * |
| * <p>See also the <a href='http://www.w3.org/TR/2004/NOTE-DOM-Level-3-XPath-20040226'>Document Object Model (DOM) Level 3 XPath Specification</a>.</p> |
| * |
| * <p>The <code>XPathExpression</code> interface represents a parsed and resolved |
| * XPath expression.</p> |
| * |
| * @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. |
| * |
| * <p>See also the <a href='http://www.w3.org/TR/2004/NOTE-DOM-Level-3-XPath-20040226'>Document Object Model (DOM) Level 3 XPath Specification</a>.</p> |
| * |
| * <p>Evaluates this XPath expression and returns a result.</p> |
| * @param contextNode The <code>context</code> is context node for the |
| * evaluation of this XPath expression.If the XPathEvaluator was |
| * obtained by casting the <code>Document</code> then this must be |
| * owned by the same document and must be a <code>Document</code>, |
| * <code>Element</code>, <code>Attribute</code>, <code>Text</code>, |
| * <code>CDATASection</code>, <code>Comment</code>, |
| * <code>ProcessingInstruction</code>, or <code>XPathNamespace</code> |
| * node.If the context node is a <code>Text</code> or a |
| * <code>CDATASection</code>, 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 <code>type</code> 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 <code>XPathResult</code>. |
| * @param result The <code>result</code> specifies a specific result |
| * object which may be reused and returned by this method. If this is |
| * specified as <code>null</code>or 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 |
| * <code>XPathResult</code>. |
| * @return The result of the evaluation of the XPath expression.For XPath |
| * 1.0 results, this object will be of type <code>XPathResult</code>. |
| * @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 |
| * <code>XPathExpression</code>. |
| * <br>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} |
| } |
| |
| // Create an XPathContext that doesn't support pushing and popping of |
| // variable resolution scopes. Sufficient for simple XPath 1.0 |
| // expressions. |
| // Cache xpath context? |
| XPathContext xpathSupport = new XPathContext(false); |
| |
| // 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); |
| } |
| |
| } |