openaz-xacml-pdp/src/main/java/org/apache/openaz/xacml/pdp/policy/FunctionArgument.java

/*
 *  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.
 *
 */

/*
 *                        AT&T - PROPRIETARY
 *          THIS FILE CONTAINS PROPRIETARY INFORMATION OF
 *        AT&T AND IS NOT TO BE DISCLOSED OR USED EXCEPT IN
 *             ACCORDANCE WITH APPLICABLE AGREEMENTS.
 *
 *          Copyright (c) 2013 AT&T Knowledge Ventures
 *              Unpublished and Not for Publication
 *                     All Rights Reserved
 */
package org.apache.openaz.xacml.pdp.policy;

import org.apache.openaz.xacml.api.AttributeValue;
import org.apache.openaz.xacml.api.Status;

/**
 * FunctionArgument is the interface implemented by objects that can serve as arguments to a
 * {@link org.apache.openaz.xacml.pdp.policy.FunctionDefinition} <code>evaluate</code> call.
 */
public interface FunctionArgument {
    /**
     * Gets the {@link org.apache.openaz.xacml.api.Status} from the evaluation of this
     * <code>FunctionArgument</code>.
     *
     * @return the <code>Status</code> from the evaluation of this <code>FunctionArgument</code>>
     */
    Status getStatus();

    /**
     * Determines if this <code>FunctionArgument</code> is OK and can have its <code>AttributeValue</code> or
     * <code>Bag</code> retrieved.
     *
     * @return true if this <code>FunctionArgument</code> is OK, otherwise false.
     */
    boolean isOk();

    /**
     * Determines if this <code>FunctionArgument</code> represents a bag of values.
     *
     * @return true if this <code>FunctionArgument</code> represents a bag of values, else false.
     */
    boolean isBag();

    /**
     * Gets the single <code>AttributeValue</code> representing the value of this
     * <code>FunctionArgument</code>. If this <code>FunctionArgument</code> represents a bag, the value
     * returned is up to the implementation.
     *
     * @return the single <code>AttributeValue</code> representing the value of this
     *         <code>FunctionArgument</code>.
     */
    AttributeValue<?> getValue();

    /**
     * Gets the {@link Bag} value for this <code>FunctionArgument</code> if the argument represents a
     * <code>Bag</code>, (i.e. <code>isBag</code> returns true).
     *
     * @return the <code>Bag</code> value for this <code>FunctionArgument</code>.
     */
    Bag getBag();

}