/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * This file is available under and governed by the GNU General Public
 * License version 2 only, as published by the Free Software Foundation.
 * However, the following notice accompanied the original version of this
 * file and, per its terms, should not be removed:
 *
 * Copyright (c) 2002 World Wide Web Consortium,
 * (Massachusetts Institute of Technology, Institut National de
 * Recherche en Informatique et en Automatique, Keio University). All
 * Rights Reserved. This program is distributed under the W3C's Software
 * Intellectual Property License. This program is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY; without even
 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE.
 * See W3C License http://www.w3.org/Consortium/Legal/ for more details.
 */

package org.w3c.dom.xpath;


import org.w3c.dom.Node;
import org.w3c.dom.DOMException;

The evaluation of XPath expressions is provided by XPathEvaluator. In a DOM implementation which supports the XPath 3.0 feature, as described above, the XPathEvaluator interface will be implemented on the same object which implements the Document interface permitting it to be obtained by the usual binding-specific method such as casting or by using the DOM Level 3 getInterface method. In this case the implementation obtained from the Document supports the XPath DOM module and is compatible with the XPath 1.0 specification.

Evaluation of expressions with specialized extension functions or variables may not work in all implementations and is, therefore, not portable. XPathEvaluator implementations may be available from other sources that could provide specific support for specialized extension functions or variables as would be defined by other specifications.

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

/** * The evaluation of XPath expressions is provided by * <code>XPathEvaluator</code>. In a DOM implementation which supports the * XPath 3.0 feature, as described above, the <code>XPathEvaluator</code> * interface will be implemented on the same object which implements the * <code>Document</code> interface permitting it to be obtained by the usual * binding-specific method such as casting or by using the DOM Level 3 * getInterface method. In this case the implementation obtained from the * Document supports the XPath DOM module and is compatible with the XPath * 1.0 specification. * <p>Evaluation of expressions with specialized extension functions or * variables may not work in all implementations and is, therefore, not * portable. <code>XPathEvaluator</code> implementations may be available * from other sources that could provide specific support for specialized * extension functions or variables as would be defined by other * specifications. * <p>See also the <a href='http://www.w3.org/2002/08/WD-DOM-Level-3-XPath-20020820'>Document Object Model (DOM) Level 3 XPath Specification</a>. */
public interface XPathEvaluator {
Creates a parsed XPath expression with resolved namespaces. This is useful when an expression will be reused in an application since it makes it possible to compile the expression string into a more efficient internal form and preresolve all namespace prefixes which occur within the expression.
Params:
  • expression – The XPath expression string to be parsed.
  • resolver – The resolver permits translation of prefixes within the XPath expression into appropriate namespace URIs . If this is specified as null, any namespace prefix within the expression will result in DOMException being thrown with the code NAMESPACE_ERR.
Throws:
  • XPathException – INVALID_EXPRESSION_ERR: Raised if the expression is not legal according to the rules of the XPathEvaluatori
  • DOMException – NAMESPACE_ERR: Raised if the expression contains namespace prefixes which cannot be resolved by the specified XPathNSResolver.
Returns:The compiled form of the XPath expression.
/** * Creates a parsed XPath expression with resolved namespaces. This is * useful when an expression will be reused in an application since it * makes it possible to compile the expression string into a more * efficient internal form and preresolve all namespace prefixes which * occur within the expression. * @param expression The XPath expression string to be parsed. * @param resolver The <code>resolver</code> permits translation of * prefixes within the XPath expression into appropriate namespace URIs * . If this is specified as <code>null</code>, any namespace prefix * within the expression will result in <code>DOMException</code> * being thrown with the code <code>NAMESPACE_ERR</code>. * @return The compiled form of the XPath expression. * @exception XPathException * INVALID_EXPRESSION_ERR: Raised if the expression is not legal * according to the rules of the <code>XPathEvaluator</code>i * @exception DOMException * NAMESPACE_ERR: Raised if the expression contains namespace prefixes * which cannot be resolved by the specified * <code>XPathNSResolver</code>. */
public XPathExpression createExpression(String expression, XPathNSResolver resolver) throws XPathException, DOMException;
Adapts any DOM node to resolve namespaces so that an XPath expression can be easily evaluated relative to the context of the node where it appeared within the document. This adapter works like the DOM Level 3 method lookupNamespaceURI on nodes in resolving the namespaceURI from a given prefix using the current information available in the node's hierarchy at the time lookupNamespaceURI is called. also correctly resolving the implicit xml prefix.
Params:
  • nodeResolver – The node to be used as a context for namespace resolution.
Returns:XPathNSResolver which resolves namespaces with respect to the definitions in scope for a specified node.
/** * Adapts any DOM node to resolve namespaces so that an XPath expression * can be easily evaluated relative to the context of the node where it * appeared within the document. This adapter works like the DOM Level 3 * method <code>lookupNamespaceURI</code> on nodes in resolving the * namespaceURI from a given prefix using the current information * available in the node's hierarchy at the time lookupNamespaceURI is * called. also correctly resolving the implicit xml prefix. * @param nodeResolver The node to be used as a context for namespace * resolution. * @return <code>XPathNSResolver</code> which resolves namespaces with * respect to the definitions in scope for a specified node. */
public XPathNSResolver createNSResolver(Node nodeResolver);
Evaluates an XPath expression string and returns a result of the specified type if possible.
Params:
  • expression – The XPath expression string to be parsed and evaluated.
  • 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.
  • resolver – The resolver permits translation of prefixes within the XPath expression into appropriate namespace URIs . If this is specified as null, any namespace prefix within the expression will result in DOMException being thrown with the code NAMESPACE_ERR.
  • type – If a specific type is specified, then the result will be returned as the corresponding type.For XPath 1.0 results, this must be one of the codes of the XPathResult interface.
  • 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.
Throws:
  • XPathException – INVALID_EXPRESSION_ERR: Raised if the expression is not legal according to the rules of the XPathEvaluatori
    TYPE_ERR: Raised if the result cannot be converted to return the specified type.
  • DOMException – NAMESPACE_ERR: Raised if the expression contains namespace prefixes which cannot be resolved by the specified XPathNSResolver.
    WRONG_DOCUMENT_ERR: The Node is from a document that is not supported by this XPathEvaluator.
    NOT_SUPPORTED_ERR: The Node is not a type permitted as an XPath context node or the request type is not permitted by this XPathEvaluator.
Returns:The result of the evaluation of the XPath expression.For XPath 1.0 results, this object will be of type XPathResult.
/** * Evaluates an XPath expression string and returns a result of the * specified type if possible. * @param expression The XPath expression string to be parsed and * evaluated. * @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 resolver The <code>resolver</code> permits translation of * prefixes within the XPath expression into appropriate namespace URIs * . If this is specified as <code>null</code>, any namespace prefix * within the expression will result in <code>DOMException</code> * being thrown with the code <code>NAMESPACE_ERR</code>. * @param type If a specific <code>type</code> is specified, then the * result will be returned as the corresponding type.For XPath 1.0 * results, this must be one of the codes of the * <code>XPathResult</code> interface. * @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 * INVALID_EXPRESSION_ERR: Raised if the expression is not legal * according to the rules of the <code>XPathEvaluator</code>i * <br>TYPE_ERR: Raised if the result cannot be converted to return the * specified type. * @exception DOMException * NAMESPACE_ERR: Raised if the expression contains namespace prefixes * which cannot be resolved by the specified * <code>XPathNSResolver</code>. * <br>WRONG_DOCUMENT_ERR: The Node is from a document that is not * supported by this <code>XPathEvaluator</code>. * <br>NOT_SUPPORTED_ERR: The Node is not a type permitted as an XPath * context node or the request type is not permitted by this * <code>XPathEvaluator</code>. */
public Object evaluate(String expression, Node contextNode, XPathNSResolver resolver, short type, Object result) throws XPathException, DOMException; }