001    /*
002     * Copyright (c) 2004 World Wide Web Consortium,
003     *
004     * (Massachusetts Institute of Technology, European Research Consortium for
005     * Informatics and Mathematics, Keio University). All Rights Reserved. This
006     * work is distributed under the W3C(r) Software License [1] in the hope that
007     * it will be useful, but WITHOUT ANY WARRANTY; without even the implied
008     * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
009     *
010     * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
011     */
012    
013    package org.w3c.dom.xpath;
014    
015    import org.w3c.dom.Node;
016    import org.w3c.dom.DOMException;
017    
018    /**
019     * The <code>XPathExpression</code> interface represents a parsed and resolved
020     * XPath expression.
021     * <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>.
022     */
023    public interface XPathExpression {
024        /**
025         * Evaluates this XPath expression and returns a result.
026         * @param contextNode The <code>context</code> is context node for the
027         *   evaluation of this XPath expression.If the XPathEvaluator was
028         *   obtained by casting the <code>Document</code> then this must be
029         *   owned by the same document and must be a <code>Document</code>,
030         *   <code>Element</code>, <code>Attribute</code>, <code>Text</code>,
031         *   <code>CDATASection</code>, <code>Comment</code>,
032         *   <code>ProcessingInstruction</code>, or <code>XPathNamespace</code>
033         *   node.If the context node is a <code>Text</code> or a
034         *   <code>CDATASection</code>, then the context is interpreted as the
035         *   whole logical text node as seen by XPath, unless the node is empty
036         *   in which case it may not serve as the XPath context.
037         * @param type If a specific <code>type</code> is specified, then the
038         *   result will be coerced to return the specified type relying on
039         *   XPath conversions and fail if the desired coercion is not possible.
040         *   This must be one of the type codes of <code>XPathResult</code>.
041         * @param result The <code>result</code> specifies a specific result
042         *   object which may be reused and returned by this method. If this is
043         *   specified as <code>null</code>or the implementation does not reuse
044         *   the specified result, a new result object will be constructed and
045         *   returned.For XPath 1.0 results, this object will be of type
046         *   <code>XPathResult</code>.
047         * @return The result of the evaluation of the XPath expression.For XPath
048         *   1.0 results, this object will be of type <code>XPathResult</code>.
049         * @exception XPathException
050         *   TYPE_ERR: Raised if the result cannot be converted to return the
051         *   specified type.
052         * @exception DOMException
053         *   WRONG_DOCUMENT_ERR: The Node is from a document that is not supported
054         *   by the XPathEvaluator that created this <code>XPathExpression</code>
055         *   .
056         *   <br>NOT_SUPPORTED_ERR: The Node is not a type permitted as an XPath
057         *   context node or the request type is not permitted by this
058         *   <code>XPathExpression</code>.
059         */
060        public Object evaluate(Node contextNode,
061                               short type,
062                               Object result)
063                               throws XPathException, DOMException;
064    
065    }