/**
 * 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.signature;

import org.apache.xml.security.transforms.TransformationException;
import org.w3c.dom.Node;

/**
 * An interface to tell to the c14n if a node is included or not in the output
 */
public interface NodeFilter {

    /**
     * Tells if a node must be output in c14n.
     * @param n
     * @return 1 if the node should be output.
     * 		   0 if node must not be output,
     * 		  -1 if the node and all it's child must not be output.
     *
     */
    int isNodeInclude(Node n) throws TransformationException;

    /**
     * Tells if a node must be output in a c14n.
     * The caller must assured that this method is always call
     * in document order. The implementations can use this
     * restriction to optimize the transformation.
     * @param n
     * @param level the relative level in the tree
     * @return 1 if the node should be output.
     * 		   0 if node must not be output,
     * 		  -1 if the node and all it's child must not be output.
     */
    int isNodeIncludeDO(Node n, int level) throws TransformationException;

}
