/*
 * @(#)AttributeProxy.java
 *
 * Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistribution of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 * 
 *   2. Redistribution in binary form must reproduce the above copyright
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 *      documentation and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
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 *
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 */

package com.sun.xacml.attr;

import org.w3c.dom.Node;


/**
 * Used by the <code>AttributeFactory</code> to create new attributes.
 * Typically a new proxy class is created which in turn knows how to create
 * a specific kind of attribute, and then this proxy class is installed in
 * the <code>AttributeFactory</code>.
 *
 * @since 1.0
 * @author Seth Proctor
 */
public interface AttributeProxy
{

    /**
     * Tries to create a new <code>AttributeValue</code> based on the given
     * DOM root node.
     *
     * @param root the DOM root of some attribute data
     *
     * @return an <code>AttributeValue</code> representing the given data
     *
     * @throws Exception if the data couldn't be used (the exception is
     *                   typically wrapping some other exception)
     */
    public AttributeValue getInstance(Node root) throws Exception;

    /**
     * Tries to create a new <code>AttributeValue</code> based on the given
     * String data.
     *
     * @param value the text form of some attribute data
     *
     * @return an <code>AttributeValue</code> representing the given data
     *
     * @throws Exception if the data couldn't be used (the exception is
     *                   typically wrapping some other exception)
     */
    public AttributeValue getInstance(String value) throws Exception;

}