/**
 * 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.
 */
package org.apache.xml.security.utils;

import javax.xml.transform.TransformerException;

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * An interface to abstract XPath evaluation
 */
public interface XPathAPI {

    /**
     *  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 xpathnode
     *  @param str
     *  @param namespaceNode The node from which prefixes in the XPath will be resolved to namespaces.
     *  @return A NodeIterator, should never be null.
     *
     * @throws TransformerException
     */
    NodeList selectNodeList(
        Node contextNode, Node xpathnode, String str, Node namespaceNode
    ) throws TransformerException;
    
    /**
     * Evaluate an XPath string and return true if the output is to be included or not.
     *  @param contextNode The node to start searching from.
     *  @param xpathnode The XPath node
     *  @param str The XPath expression
     *  @param namespaceNode The node from which prefixes in the XPath will be resolved to namespaces.
     */
    boolean evaluate(Node contextNode, Node xpathnode, String str, Node namespaceNode)
        throws TransformerException;
    
    /**
     * Clear any context information from this object
     */
    void clear();

}